![Full Jet-Reconstruction in STAR · 0.2 0.6 1.0 1.4 1.8 1/2 π d σ /(d η dp T) [pb/GeV] data / theory p [GeV/c] T 0 10 20 30 40 50 2 (a) (b) Combined MB Combined HT NLO QCD (Vogelsang)](https://static.fdocuments.us/doc/165x107/5fd6de9868b72036ef5ba689/full-jet-reconstruction-in-star-02-06-10-14-18-12-d-f-d-dp-t-pbgev.jpg)
Kinematic reconstruction of the W mass and width at FCC-ee · 2019. 11. 18. · Direct...
22
Draft Marina B´ eguin W study at FCC-ee November 18, 2019 1 / 15 Kinematic reconstruction of the W mass and width at FCC-ee Marina B´ eguin On behalf of the FCC-ee WG2 working group CEPC workshop November 18, 2019
Transcript of Kinematic reconstruction of the W mass and width at FCC-ee · 2019. 11. 18. · Direct...
Dra
ftMarina Beguin W study at FCC-ee November 18 2019 1 15
Kinematic reconstruction of the W mass andwidth at FCC-ee
Marina Beguin
On behalf of the FCC-ee WG2 working groupCEPC workshop
November 18 2019
FCC-eeFCC-hh 100 TeVOption FCC-he
Z WW HZ ttsim 91 GeV sim 160 GeV sim 240 GeV sim 350-365 GeV
Detectors e+eminus CLD and IDEA
WW factoryradics = 160 GeV L = 12 abminus1
rarr 60106 WW
radics = 240 GeV L = 5 abminus1
rarr 80106 WW
radics = 350 minus 365 GeV L = 17 abminus1
rarr 20106 WW
WW diboson physics at FCC-ee
Measurements of the W mass andwidth directly and with threshold scan
W partial widths
Strong coupling constant
CKM matrix
Gauge self-couplings
with unprecedented accuracy
W mass measurement
Marina Beguin W study at FCC-ee November 18 2019 5 15
Precise relation between MW MH Mt is a crucial test of
the internal consistency of SM and failure might reveal
new physics
At WW threshold
Direct determination
Methods
CLIC-Like Detector CLD
Marina Beguin W study at FCC-ee November 18 2019 6 15
More information in FCC CDR v2
Detector simulation softwareFCCSW and heppy
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Study at 1626 GeV 240 GeV and 365 GeV
pythia v824 simulation
Reconstruction withheppy (CLD detectordurham algorithm)
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 7 15
W mass estimators
Raw mass
4C jets momenta rescaling
Kinematic fit with energy-momentum conservation (4C) and Wmasses equality (5C)
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Statistical uncertainty estimated with a binned maximum likelihoodfit on the reconstructed MW distributions using templates with dif-ferent nominal W mass (width) values
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
02
04
06
08
1
12
14
16
18
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detector qqqqrarrWW
5C Kinematic Fit4C Kinematic Fit4C Kinematic rescalingRaw MassThreshold method
Marina Beguin W study at FCC-ee November 18 2019 8 15
1626 GeV∆ΓW (4C) = 11 MeV
240 GeV∆ΓW (5C) = 047 MeV
365 GeV∆ΓW (5C) = 1 MeV
Mass and width uncertaintiesevaluated independently
Full FCC-ee luminosity
Th
resh
old
mea
sure
men
th
ere
Direct reconstruction of MW and ΓW
Semi-leptonic decay channel WW rarr qq`ν
Study at 1626 GeV 240 GeV and 365 GeV
Only the muon decay
Marina Beguin W study at FCC-ee November 18 2019 9 15
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
0
02
04
06
08
1
12
14
16
18
2
22
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detectorνmicro qqrarrWW
Raw mass
1C Kinematic Fit
2C Kinematic Fit
Threshold method
Full FCC-ee luminosity
1626 GeV ∆ΓW (1C) = 035 MeV240 GeV ∆ΓW (2C) = 068 MeV365 GeV ∆ΓW (2C) = 156 MeV
Threshold measurement here
Direct reconstruction of MW and ΓW at threshold
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 10 15
Had
roni
cch
anne
lS
emi-leptonic
channel
Direct reconstruction can be used to extract W mass and width at threshold
W mass and width statistical uncertaintiesTable Hadronic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 166 049 097 144 110 171
4C rescaling 172 036 073 153 077 148
4C fit 113 028 05 11 058 095
5C fit 021 044 047 10
With threshold method σMW= 023 MeV
Threshold measurement here
Table Semi-leptonic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 042 049 119 039 087 194
1C fit 026 033 078 035 059 136
2C fit 031 075 068 156
Marina Beguin W study at FCC-ee November 18 2019 11 15
Full FCC-ee luminosity
Systematic uncertainties
radics [GeV] 1626 240 365
δMFSI [MeV] standard cone standard cone standard coneSKI 146 75 239 115 322 175SKII 79 38 121 60 147 83BEC 31 18 59 21 99 55
Marina Beguin W study at FCC-ee November 18 2019 12 15
40 50 60 70 80 90 100 110 120 (5C) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7689
Std Dev 9452
Wo treatment
Cone 04 rad
240 GeV
CLD Detector qqqqrarrWW
Main sources of systematic uncertainties at LEP2arXiv13023415 FSI simulated with pythia (SKISKII)
δMW FSI reduced using a cone(04 rad) on jets
∆MW stat is degraded with the cone by a few percents at threshold and 10-15 above
without FSI
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
FCC-eeFCC-hh 100 TeVOption FCC-he
Z WW HZ ttsim 91 GeV sim 160 GeV sim 240 GeV sim 350-365 GeV
Detectors e+eminus CLD and IDEA
WW factoryradics = 160 GeV L = 12 abminus1
rarr 60106 WW
radics = 240 GeV L = 5 abminus1
rarr 80106 WW
radics = 350 minus 365 GeV L = 17 abminus1
rarr 20106 WW
WW diboson physics at FCC-ee
Measurements of the W mass andwidth directly and with threshold scan
W partial widths
Strong coupling constant
CKM matrix
Gauge self-couplings
with unprecedented accuracy
W mass measurement
Marina Beguin W study at FCC-ee November 18 2019 5 15
Precise relation between MW MH Mt is a crucial test of
the internal consistency of SM and failure might reveal
new physics
At WW threshold
Direct determination
Methods
CLIC-Like Detector CLD
Marina Beguin W study at FCC-ee November 18 2019 6 15
More information in FCC CDR v2
Detector simulation softwareFCCSW and heppy
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Study at 1626 GeV 240 GeV and 365 GeV
pythia v824 simulation
Reconstruction withheppy (CLD detectordurham algorithm)
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 7 15
W mass estimators
Raw mass
4C jets momenta rescaling
Kinematic fit with energy-momentum conservation (4C) and Wmasses equality (5C)
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Statistical uncertainty estimated with a binned maximum likelihoodfit on the reconstructed MW distributions using templates with dif-ferent nominal W mass (width) values
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
02
04
06
08
1
12
14
16
18
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detector qqqqrarrWW
5C Kinematic Fit4C Kinematic Fit4C Kinematic rescalingRaw MassThreshold method
Marina Beguin W study at FCC-ee November 18 2019 8 15
1626 GeV∆ΓW (4C) = 11 MeV
240 GeV∆ΓW (5C) = 047 MeV
365 GeV∆ΓW (5C) = 1 MeV
Mass and width uncertaintiesevaluated independently
Full FCC-ee luminosity
Th
resh
old
mea
sure
men
th
ere
Direct reconstruction of MW and ΓW
Semi-leptonic decay channel WW rarr qq`ν
Study at 1626 GeV 240 GeV and 365 GeV
Only the muon decay
Marina Beguin W study at FCC-ee November 18 2019 9 15
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
0
02
04
06
08
1
12
14
16
18
2
22
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detectorνmicro qqrarrWW
Raw mass
1C Kinematic Fit
2C Kinematic Fit
Threshold method
Full FCC-ee luminosity
1626 GeV ∆ΓW (1C) = 035 MeV240 GeV ∆ΓW (2C) = 068 MeV365 GeV ∆ΓW (2C) = 156 MeV
Threshold measurement here
Direct reconstruction of MW and ΓW at threshold
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 10 15
Had
roni
cch
anne
lS
emi-leptonic
channel
Direct reconstruction can be used to extract W mass and width at threshold
W mass and width statistical uncertaintiesTable Hadronic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 166 049 097 144 110 171
4C rescaling 172 036 073 153 077 148
4C fit 113 028 05 11 058 095
5C fit 021 044 047 10
With threshold method σMW= 023 MeV
Threshold measurement here
Table Semi-leptonic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 042 049 119 039 087 194
1C fit 026 033 078 035 059 136
2C fit 031 075 068 156
Marina Beguin W study at FCC-ee November 18 2019 11 15
Full FCC-ee luminosity
Systematic uncertainties
radics [GeV] 1626 240 365
δMFSI [MeV] standard cone standard cone standard coneSKI 146 75 239 115 322 175SKII 79 38 121 60 147 83BEC 31 18 59 21 99 55
Marina Beguin W study at FCC-ee November 18 2019 12 15
40 50 60 70 80 90 100 110 120 (5C) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7689
Std Dev 9452
Wo treatment
Cone 04 rad
240 GeV
CLD Detector qqqqrarrWW
Main sources of systematic uncertainties at LEP2arXiv13023415 FSI simulated with pythia (SKISKII)
δMW FSI reduced using a cone(04 rad) on jets
∆MW stat is degraded with the cone by a few percents at threshold and 10-15 above
without FSI
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
WW factoryradics = 160 GeV L = 12 abminus1
rarr 60106 WW
radics = 240 GeV L = 5 abminus1
rarr 80106 WW
radics = 350 minus 365 GeV L = 17 abminus1
rarr 20106 WW
WW diboson physics at FCC-ee
Measurements of the W mass andwidth directly and with threshold scan
W partial widths
Strong coupling constant
CKM matrix
Gauge self-couplings
with unprecedented accuracy
W mass measurement
Marina Beguin W study at FCC-ee November 18 2019 5 15
Precise relation between MW MH Mt is a crucial test of
the internal consistency of SM and failure might reveal
new physics
At WW threshold
Direct determination
Methods
CLIC-Like Detector CLD
Marina Beguin W study at FCC-ee November 18 2019 6 15
More information in FCC CDR v2
Detector simulation softwareFCCSW and heppy
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Study at 1626 GeV 240 GeV and 365 GeV
pythia v824 simulation
Reconstruction withheppy (CLD detectordurham algorithm)
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 7 15
W mass estimators
Raw mass
4C jets momenta rescaling
Kinematic fit with energy-momentum conservation (4C) and Wmasses equality (5C)
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Statistical uncertainty estimated with a binned maximum likelihoodfit on the reconstructed MW distributions using templates with dif-ferent nominal W mass (width) values
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
02
04
06
08
1
12
14
16
18
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detector qqqqrarrWW
5C Kinematic Fit4C Kinematic Fit4C Kinematic rescalingRaw MassThreshold method
Marina Beguin W study at FCC-ee November 18 2019 8 15
1626 GeV∆ΓW (4C) = 11 MeV
240 GeV∆ΓW (5C) = 047 MeV
365 GeV∆ΓW (5C) = 1 MeV
Mass and width uncertaintiesevaluated independently
Full FCC-ee luminosity
Th
resh
old
mea
sure
men
th
ere
Direct reconstruction of MW and ΓW
Semi-leptonic decay channel WW rarr qq`ν
Study at 1626 GeV 240 GeV and 365 GeV
Only the muon decay
Marina Beguin W study at FCC-ee November 18 2019 9 15
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
0
02
04
06
08
1
12
14
16
18
2
22
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detectorνmicro qqrarrWW
Raw mass
1C Kinematic Fit
2C Kinematic Fit
Threshold method
Full FCC-ee luminosity
1626 GeV ∆ΓW (1C) = 035 MeV240 GeV ∆ΓW (2C) = 068 MeV365 GeV ∆ΓW (2C) = 156 MeV
Threshold measurement here
Direct reconstruction of MW and ΓW at threshold
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 10 15
Had
roni
cch
anne
lS
emi-leptonic
channel
Direct reconstruction can be used to extract W mass and width at threshold
W mass and width statistical uncertaintiesTable Hadronic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 166 049 097 144 110 171
4C rescaling 172 036 073 153 077 148
4C fit 113 028 05 11 058 095
5C fit 021 044 047 10
With threshold method σMW= 023 MeV
Threshold measurement here
Table Semi-leptonic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 042 049 119 039 087 194
1C fit 026 033 078 035 059 136
2C fit 031 075 068 156
Marina Beguin W study at FCC-ee November 18 2019 11 15
Full FCC-ee luminosity
Systematic uncertainties
radics [GeV] 1626 240 365
δMFSI [MeV] standard cone standard cone standard coneSKI 146 75 239 115 322 175SKII 79 38 121 60 147 83BEC 31 18 59 21 99 55
Marina Beguin W study at FCC-ee November 18 2019 12 15
40 50 60 70 80 90 100 110 120 (5C) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7689
Std Dev 9452
Wo treatment
Cone 04 rad
240 GeV
CLD Detector qqqqrarrWW
Main sources of systematic uncertainties at LEP2arXiv13023415 FSI simulated with pythia (SKISKII)
δMW FSI reduced using a cone(04 rad) on jets
∆MW stat is degraded with the cone by a few percents at threshold and 10-15 above
without FSI
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
WW diboson physics at FCC-ee
Measurements of the W mass andwidth directly and with threshold scan
W partial widths
Strong coupling constant
CKM matrix
Gauge self-couplings
with unprecedented accuracy
W mass measurement
Marina Beguin W study at FCC-ee November 18 2019 5 15
Precise relation between MW MH Mt is a crucial test of
the internal consistency of SM and failure might reveal
new physics
At WW threshold
Direct determination
Methods
CLIC-Like Detector CLD
Marina Beguin W study at FCC-ee November 18 2019 6 15
More information in FCC CDR v2
Detector simulation softwareFCCSW and heppy
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Study at 1626 GeV 240 GeV and 365 GeV
pythia v824 simulation
Reconstruction withheppy (CLD detectordurham algorithm)
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 7 15
W mass estimators
Raw mass
4C jets momenta rescaling
Kinematic fit with energy-momentum conservation (4C) and Wmasses equality (5C)
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Statistical uncertainty estimated with a binned maximum likelihoodfit on the reconstructed MW distributions using templates with dif-ferent nominal W mass (width) values
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
02
04
06
08
1
12
14
16
18
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detector qqqqrarrWW
5C Kinematic Fit4C Kinematic Fit4C Kinematic rescalingRaw MassThreshold method
Marina Beguin W study at FCC-ee November 18 2019 8 15
1626 GeV∆ΓW (4C) = 11 MeV
240 GeV∆ΓW (5C) = 047 MeV
365 GeV∆ΓW (5C) = 1 MeV
Mass and width uncertaintiesevaluated independently
Full FCC-ee luminosity
Th
resh
old
mea
sure
men
th
ere
Direct reconstruction of MW and ΓW
Semi-leptonic decay channel WW rarr qq`ν
Study at 1626 GeV 240 GeV and 365 GeV
Only the muon decay
Marina Beguin W study at FCC-ee November 18 2019 9 15
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
0
02
04
06
08
1
12
14
16
18
2
22
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detectorνmicro qqrarrWW
Raw mass
1C Kinematic Fit
2C Kinematic Fit
Threshold method
Full FCC-ee luminosity
1626 GeV ∆ΓW (1C) = 035 MeV240 GeV ∆ΓW (2C) = 068 MeV365 GeV ∆ΓW (2C) = 156 MeV
Threshold measurement here
Direct reconstruction of MW and ΓW at threshold
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 10 15
Had
roni
cch
anne
lS
emi-leptonic
channel
Direct reconstruction can be used to extract W mass and width at threshold
W mass and width statistical uncertaintiesTable Hadronic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 166 049 097 144 110 171
4C rescaling 172 036 073 153 077 148
4C fit 113 028 05 11 058 095
5C fit 021 044 047 10
With threshold method σMW= 023 MeV
Threshold measurement here
Table Semi-leptonic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 042 049 119 039 087 194
1C fit 026 033 078 035 059 136
2C fit 031 075 068 156
Marina Beguin W study at FCC-ee November 18 2019 11 15
Full FCC-ee luminosity
Systematic uncertainties
radics [GeV] 1626 240 365
δMFSI [MeV] standard cone standard cone standard coneSKI 146 75 239 115 322 175SKII 79 38 121 60 147 83BEC 31 18 59 21 99 55
Marina Beguin W study at FCC-ee November 18 2019 12 15
40 50 60 70 80 90 100 110 120 (5C) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7689
Std Dev 9452
Wo treatment
Cone 04 rad
240 GeV
CLD Detector qqqqrarrWW
Main sources of systematic uncertainties at LEP2arXiv13023415 FSI simulated with pythia (SKISKII)
δMW FSI reduced using a cone(04 rad) on jets
∆MW stat is degraded with the cone by a few percents at threshold and 10-15 above
without FSI
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
W mass measurement
Marina Beguin W study at FCC-ee November 18 2019 5 15
Precise relation between MW MH Mt is a crucial test of
the internal consistency of SM and failure might reveal
new physics
At WW threshold
Direct determination
Methods
CLIC-Like Detector CLD
Marina Beguin W study at FCC-ee November 18 2019 6 15
More information in FCC CDR v2
Detector simulation softwareFCCSW and heppy
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Study at 1626 GeV 240 GeV and 365 GeV
pythia v824 simulation
Reconstruction withheppy (CLD detectordurham algorithm)
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 7 15
W mass estimators
Raw mass
4C jets momenta rescaling
Kinematic fit with energy-momentum conservation (4C) and Wmasses equality (5C)
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Statistical uncertainty estimated with a binned maximum likelihoodfit on the reconstructed MW distributions using templates with dif-ferent nominal W mass (width) values
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
02
04
06
08
1
12
14
16
18
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detector qqqqrarrWW
5C Kinematic Fit4C Kinematic Fit4C Kinematic rescalingRaw MassThreshold method
Marina Beguin W study at FCC-ee November 18 2019 8 15
1626 GeV∆ΓW (4C) = 11 MeV
240 GeV∆ΓW (5C) = 047 MeV
365 GeV∆ΓW (5C) = 1 MeV
Mass and width uncertaintiesevaluated independently
Full FCC-ee luminosity
Th
resh
old
mea
sure
men
th
ere
Direct reconstruction of MW and ΓW
Semi-leptonic decay channel WW rarr qq`ν
Study at 1626 GeV 240 GeV and 365 GeV
Only the muon decay
Marina Beguin W study at FCC-ee November 18 2019 9 15
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
0
02
04
06
08
1
12
14
16
18
2
22
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detectorνmicro qqrarrWW
Raw mass
1C Kinematic Fit
2C Kinematic Fit
Threshold method
Full FCC-ee luminosity
1626 GeV ∆ΓW (1C) = 035 MeV240 GeV ∆ΓW (2C) = 068 MeV365 GeV ∆ΓW (2C) = 156 MeV
Threshold measurement here
Direct reconstruction of MW and ΓW at threshold
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 10 15
Had
roni
cch
anne
lS
emi-leptonic
channel
Direct reconstruction can be used to extract W mass and width at threshold
W mass and width statistical uncertaintiesTable Hadronic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 166 049 097 144 110 171
4C rescaling 172 036 073 153 077 148
4C fit 113 028 05 11 058 095
5C fit 021 044 047 10
With threshold method σMW= 023 MeV
Threshold measurement here
Table Semi-leptonic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 042 049 119 039 087 194
1C fit 026 033 078 035 059 136
2C fit 031 075 068 156
Marina Beguin W study at FCC-ee November 18 2019 11 15
Full FCC-ee luminosity
Systematic uncertainties
radics [GeV] 1626 240 365
δMFSI [MeV] standard cone standard cone standard coneSKI 146 75 239 115 322 175SKII 79 38 121 60 147 83BEC 31 18 59 21 99 55
Marina Beguin W study at FCC-ee November 18 2019 12 15
40 50 60 70 80 90 100 110 120 (5C) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7689
Std Dev 9452
Wo treatment
Cone 04 rad
240 GeV
CLD Detector qqqqrarrWW
Main sources of systematic uncertainties at LEP2arXiv13023415 FSI simulated with pythia (SKISKII)
δMW FSI reduced using a cone(04 rad) on jets
∆MW stat is degraded with the cone by a few percents at threshold and 10-15 above
without FSI
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
CLIC-Like Detector CLD
Marina Beguin W study at FCC-ee November 18 2019 6 15
More information in FCC CDR v2
Detector simulation softwareFCCSW and heppy
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Study at 1626 GeV 240 GeV and 365 GeV
pythia v824 simulation
Reconstruction withheppy (CLD detectordurham algorithm)
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 7 15
W mass estimators
Raw mass
4C jets momenta rescaling
Kinematic fit with energy-momentum conservation (4C) and Wmasses equality (5C)
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Statistical uncertainty estimated with a binned maximum likelihoodfit on the reconstructed MW distributions using templates with dif-ferent nominal W mass (width) values
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
02
04
06
08
1
12
14
16
18
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detector qqqqrarrWW
5C Kinematic Fit4C Kinematic Fit4C Kinematic rescalingRaw MassThreshold method
Marina Beguin W study at FCC-ee November 18 2019 8 15
1626 GeV∆ΓW (4C) = 11 MeV
240 GeV∆ΓW (5C) = 047 MeV
365 GeV∆ΓW (5C) = 1 MeV
Mass and width uncertaintiesevaluated independently
Full FCC-ee luminosity
Th
resh
old
mea
sure
men
th
ere
Direct reconstruction of MW and ΓW
Semi-leptonic decay channel WW rarr qq`ν
Study at 1626 GeV 240 GeV and 365 GeV
Only the muon decay
Marina Beguin W study at FCC-ee November 18 2019 9 15
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
0
02
04
06
08
1
12
14
16
18
2
22
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detectorνmicro qqrarrWW
Raw mass
1C Kinematic Fit
2C Kinematic Fit
Threshold method
Full FCC-ee luminosity
1626 GeV ∆ΓW (1C) = 035 MeV240 GeV ∆ΓW (2C) = 068 MeV365 GeV ∆ΓW (2C) = 156 MeV
Threshold measurement here
Direct reconstruction of MW and ΓW at threshold
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 10 15
Had
roni
cch
anne
lS
emi-leptonic
channel
Direct reconstruction can be used to extract W mass and width at threshold
W mass and width statistical uncertaintiesTable Hadronic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 166 049 097 144 110 171
4C rescaling 172 036 073 153 077 148
4C fit 113 028 05 11 058 095
5C fit 021 044 047 10
With threshold method σMW= 023 MeV
Threshold measurement here
Table Semi-leptonic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 042 049 119 039 087 194
1C fit 026 033 078 035 059 136
2C fit 031 075 068 156
Marina Beguin W study at FCC-ee November 18 2019 11 15
Full FCC-ee luminosity
Systematic uncertainties
radics [GeV] 1626 240 365
δMFSI [MeV] standard cone standard cone standard coneSKI 146 75 239 115 322 175SKII 79 38 121 60 147 83BEC 31 18 59 21 99 55
Marina Beguin W study at FCC-ee November 18 2019 12 15
40 50 60 70 80 90 100 110 120 (5C) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7689
Std Dev 9452
Wo treatment
Cone 04 rad
240 GeV
CLD Detector qqqqrarrWW
Main sources of systematic uncertainties at LEP2arXiv13023415 FSI simulated with pythia (SKISKII)
δMW FSI reduced using a cone(04 rad) on jets
∆MW stat is degraded with the cone by a few percents at threshold and 10-15 above
without FSI
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Study at 1626 GeV 240 GeV and 365 GeV
pythia v824 simulation
Reconstruction withheppy (CLD detectordurham algorithm)
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 7 15
W mass estimators
Raw mass
4C jets momenta rescaling
Kinematic fit with energy-momentum conservation (4C) and Wmasses equality (5C)
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Statistical uncertainty estimated with a binned maximum likelihoodfit on the reconstructed MW distributions using templates with dif-ferent nominal W mass (width) values
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
02
04
06
08
1
12
14
16
18
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detector qqqqrarrWW
5C Kinematic Fit4C Kinematic Fit4C Kinematic rescalingRaw MassThreshold method
Marina Beguin W study at FCC-ee November 18 2019 8 15
1626 GeV∆ΓW (4C) = 11 MeV
240 GeV∆ΓW (5C) = 047 MeV
365 GeV∆ΓW (5C) = 1 MeV
Mass and width uncertaintiesevaluated independently
Full FCC-ee luminosity
Th
resh
old
mea
sure
men
th
ere
Direct reconstruction of MW and ΓW
Semi-leptonic decay channel WW rarr qq`ν
Study at 1626 GeV 240 GeV and 365 GeV
Only the muon decay
Marina Beguin W study at FCC-ee November 18 2019 9 15
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
0
02
04
06
08
1
12
14
16
18
2
22
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detectorνmicro qqrarrWW
Raw mass
1C Kinematic Fit
2C Kinematic Fit
Threshold method
Full FCC-ee luminosity
1626 GeV ∆ΓW (1C) = 035 MeV240 GeV ∆ΓW (2C) = 068 MeV365 GeV ∆ΓW (2C) = 156 MeV
Threshold measurement here
Direct reconstruction of MW and ΓW at threshold
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 10 15
Had
roni
cch
anne
lS
emi-leptonic
channel
Direct reconstruction can be used to extract W mass and width at threshold
W mass and width statistical uncertaintiesTable Hadronic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 166 049 097 144 110 171
4C rescaling 172 036 073 153 077 148
4C fit 113 028 05 11 058 095
5C fit 021 044 047 10
With threshold method σMW= 023 MeV
Threshold measurement here
Table Semi-leptonic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 042 049 119 039 087 194
1C fit 026 033 078 035 059 136
2C fit 031 075 068 156
Marina Beguin W study at FCC-ee November 18 2019 11 15
Full FCC-ee luminosity
Systematic uncertainties
radics [GeV] 1626 240 365
δMFSI [MeV] standard cone standard cone standard coneSKI 146 75 239 115 322 175SKII 79 38 121 60 147 83BEC 31 18 59 21 99 55
Marina Beguin W study at FCC-ee November 18 2019 12 15
40 50 60 70 80 90 100 110 120 (5C) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7689
Std Dev 9452
Wo treatment
Cone 04 rad
240 GeV
CLD Detector qqqqrarrWW
Main sources of systematic uncertainties at LEP2arXiv13023415 FSI simulated with pythia (SKISKII)
δMW FSI reduced using a cone(04 rad) on jets
∆MW stat is degraded with the cone by a few percents at threshold and 10-15 above
without FSI
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
Direct reconstruction of MW and ΓW
Hadronic decay channel WW rarr qqqq
Statistical uncertainty estimated with a binned maximum likelihoodfit on the reconstructed MW distributions using templates with dif-ferent nominal W mass (width) values
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
02
04
06
08
1
12
14
16
18
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detector qqqqrarrWW
5C Kinematic Fit4C Kinematic Fit4C Kinematic rescalingRaw MassThreshold method
Marina Beguin W study at FCC-ee November 18 2019 8 15
1626 GeV∆ΓW (4C) = 11 MeV
240 GeV∆ΓW (5C) = 047 MeV
365 GeV∆ΓW (5C) = 1 MeV
Mass and width uncertaintiesevaluated independently
Full FCC-ee luminosity
Th
resh
old
mea
sure
men
th
ere
Direct reconstruction of MW and ΓW
Semi-leptonic decay channel WW rarr qq`ν
Study at 1626 GeV 240 GeV and 365 GeV
Only the muon decay
Marina Beguin W study at FCC-ee November 18 2019 9 15
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
0
02
04
06
08
1
12
14
16
18
2
22
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detectorνmicro qqrarrWW
Raw mass
1C Kinematic Fit
2C Kinematic Fit
Threshold method
Full FCC-ee luminosity
1626 GeV ∆ΓW (1C) = 035 MeV240 GeV ∆ΓW (2C) = 068 MeV365 GeV ∆ΓW (2C) = 156 MeV
Threshold measurement here
Direct reconstruction of MW and ΓW at threshold
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 10 15
Had
roni
cch
anne
lS
emi-leptonic
channel
Direct reconstruction can be used to extract W mass and width at threshold
W mass and width statistical uncertaintiesTable Hadronic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 166 049 097 144 110 171
4C rescaling 172 036 073 153 077 148
4C fit 113 028 05 11 058 095
5C fit 021 044 047 10
With threshold method σMW= 023 MeV
Threshold measurement here
Table Semi-leptonic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 042 049 119 039 087 194
1C fit 026 033 078 035 059 136
2C fit 031 075 068 156
Marina Beguin W study at FCC-ee November 18 2019 11 15
Full FCC-ee luminosity
Systematic uncertainties
radics [GeV] 1626 240 365
δMFSI [MeV] standard cone standard cone standard coneSKI 146 75 239 115 322 175SKII 79 38 121 60 147 83BEC 31 18 59 21 99 55
Marina Beguin W study at FCC-ee November 18 2019 12 15
40 50 60 70 80 90 100 110 120 (5C) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7689
Std Dev 9452
Wo treatment
Cone 04 rad
240 GeV
CLD Detector qqqqrarrWW
Main sources of systematic uncertainties at LEP2arXiv13023415 FSI simulated with pythia (SKISKII)
δMW FSI reduced using a cone(04 rad) on jets
∆MW stat is degraded with the cone by a few percents at threshold and 10-15 above
without FSI
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
Direct reconstruction of MW and ΓW
Semi-leptonic decay channel WW rarr qq`ν
Study at 1626 GeV 240 GeV and 365 GeV
Only the muon decay
Marina Beguin W study at FCC-ee November 18 2019 9 15
160 180 200 220 240 260 280 300 320 340 360 380 [GeV]s
0
02
04
06
08
1
12
14
16
18
2
22
[M
eV]
W s
tat
M∆
1626 GeV-1 12 abW stat M∆ 240 GeV-1 5 abW stat M∆
365 GeV-1 17 abW stat M∆
CLD Detectorνmicro qqrarrWW
Raw mass
1C Kinematic Fit
2C Kinematic Fit
Threshold method
Full FCC-ee luminosity
1626 GeV ∆ΓW (1C) = 035 MeV240 GeV ∆ΓW (2C) = 068 MeV365 GeV ∆ΓW (2C) = 156 MeV
Threshold measurement here
Direct reconstruction of MW and ΓW at threshold
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 10 15
Had
roni
cch
anne
lS
emi-leptonic
channel
Direct reconstruction can be used to extract W mass and width at threshold
W mass and width statistical uncertaintiesTable Hadronic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 166 049 097 144 110 171
4C rescaling 172 036 073 153 077 148
4C fit 113 028 05 11 058 095
5C fit 021 044 047 10
With threshold method σMW= 023 MeV
Threshold measurement here
Table Semi-leptonic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 042 049 119 039 087 194
1C fit 026 033 078 035 059 136
2C fit 031 075 068 156
Marina Beguin W study at FCC-ee November 18 2019 11 15
Full FCC-ee luminosity
Systematic uncertainties
radics [GeV] 1626 240 365
δMFSI [MeV] standard cone standard cone standard coneSKI 146 75 239 115 322 175SKII 79 38 121 60 147 83BEC 31 18 59 21 99 55
Marina Beguin W study at FCC-ee November 18 2019 12 15
40 50 60 70 80 90 100 110 120 (5C) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7689
Std Dev 9452
Wo treatment
Cone 04 rad
240 GeV
CLD Detector qqqqrarrWW
Main sources of systematic uncertainties at LEP2arXiv13023415 FSI simulated with pythia (SKISKII)
δMW FSI reduced using a cone(04 rad) on jets
∆MW stat is degraded with the cone by a few percents at threshold and 10-15 above
without FSI
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
Direct reconstruction of MW and ΓW at threshold
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 10 15
Had
roni
cch
anne
lS
emi-leptonic
channel
Direct reconstruction can be used to extract W mass and width at threshold
W mass and width statistical uncertaintiesTable Hadronic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 166 049 097 144 110 171
4C rescaling 172 036 073 153 077 148
4C fit 113 028 05 11 058 095
5C fit 021 044 047 10
With threshold method σMW= 023 MeV
Threshold measurement here
Table Semi-leptonic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 042 049 119 039 087 194
1C fit 026 033 078 035 059 136
2C fit 031 075 068 156
Marina Beguin W study at FCC-ee November 18 2019 11 15
Full FCC-ee luminosity
Systematic uncertainties
radics [GeV] 1626 240 365
δMFSI [MeV] standard cone standard cone standard coneSKI 146 75 239 115 322 175SKII 79 38 121 60 147 83BEC 31 18 59 21 99 55
Marina Beguin W study at FCC-ee November 18 2019 12 15
40 50 60 70 80 90 100 110 120 (5C) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7689
Std Dev 9452
Wo treatment
Cone 04 rad
240 GeV
CLD Detector qqqqrarrWW
Main sources of systematic uncertainties at LEP2arXiv13023415 FSI simulated with pythia (SKISKII)
δMW FSI reduced using a cone(04 rad) on jets
∆MW stat is degraded with the cone by a few percents at threshold and 10-15 above
without FSI
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
W mass and width statistical uncertaintiesTable Hadronic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 166 049 097 144 110 171
4C rescaling 172 036 073 153 077 148
4C fit 113 028 05 11 058 095
5C fit 021 044 047 10
With threshold method σMW= 023 MeV
Threshold measurement here
Table Semi-leptonic decay
σMW[MeVc2] σΓW [MeVc2]
radic
s [GeV] 1626 240 365 1626 240 365
Luminosity (abminus1) 12 5 17 12 5 17
Raw Mass 042 049 119 039 087 194
1C fit 026 033 078 035 059 136
2C fit 031 075 068 156
Marina Beguin W study at FCC-ee November 18 2019 11 15
Full FCC-ee luminosity
Systematic uncertainties
radics [GeV] 1626 240 365
δMFSI [MeV] standard cone standard cone standard coneSKI 146 75 239 115 322 175SKII 79 38 121 60 147 83BEC 31 18 59 21 99 55
Marina Beguin W study at FCC-ee November 18 2019 12 15
40 50 60 70 80 90 100 110 120 (5C) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7689
Std Dev 9452
Wo treatment
Cone 04 rad
240 GeV
CLD Detector qqqqrarrWW
Main sources of systematic uncertainties at LEP2arXiv13023415 FSI simulated with pythia (SKISKII)
δMW FSI reduced using a cone(04 rad) on jets
∆MW stat is degraded with the cone by a few percents at threshold and 10-15 above
without FSI
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
Systematic uncertainties
radics [GeV] 1626 240 365
δMFSI [MeV] standard cone standard cone standard coneSKI 146 75 239 115 322 175SKII 79 38 121 60 147 83BEC 31 18 59 21 99 55
Marina Beguin W study at FCC-ee November 18 2019 12 15
40 50 60 70 80 90 100 110 120 (5C) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7689
Std Dev 9452
Wo treatment
Cone 04 rad
240 GeV
CLD Detector qqqqrarrWW
Main sources of systematic uncertainties at LEP2arXiv13023415 FSI simulated with pythia (SKISKII)
δMW FSI reduced using a cone(04 rad) on jets
∆MW stat is degraded with the cone by a few percents at threshold and 10-15 above
without FSI
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
Background contamination in hadronic channel
Background processes studied at 1626 GeV 240 GeV and 365 GeV (ifpossible)
e+eminus rarr qq(γ)
e+eminus rarrWW rarr qq``
e+eminus rarr ZZ rarr 4f
e+eminus rarr ZH rarr qqqq
e+eminus rarr ZH rarr qq``
Marina Beguin W study at FCC-ee November 18 2019 13 15
Sofiane Lablack
Bkg rejection increases with energy1626 GeV p = 041 ε = 037365 GeV p = 085 ε = 036
⊳ Effective backgroundrejection above threshold
⊳ ∆MW (5C) = 027 MeV240 GeV (5abminus1) inpresence of background(021 MeV without)
Sofiane Lablack Precise measurement of the W boson mass atthe e+eminus future circular collider (FCC-ee) Master Thesis 2019
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
Conclusion
The amount of W-pairs at different centre-of-mass energies plannedat FCC-ee presents a huge potential for the W physics measurements
Direct MW and ΓW measurements at threshold and above ispossible at FCC-ee Yielding to statistical precision belowMeV-level (∆MW = 210 keV 240 GeV for hadronic channeland ∆MW = 260 keV 1626 GeV for semi-leptonic channel)
Measurement of the centre-of-mass energy with good precision(2 MeV 365 GeV) for energies above the WW threshold wherethe resonant depolarisation cannot be used (more informationhere)
Ultimately a simultaneous fit of WW ZZ and Zγ events couldbe performed to extract mW mZ with potential largecancellations of systematic uncertainties
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
Thank you谢谢谢谢谢谢
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
BACK-UP
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
W mass distributions - Hadronic channel
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
Mean 689
Std Dev 9604
Mean 6754
Std Dev 9845
Mean 6711
Std Dev 983
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8154
Std Dev 7732
Mean 8259
Std Dev 8666
1626 GeV qqqqrarrWW
4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 7407
Std Dev 9779
Mean 7313
Std Dev 9977
Mean 7439
Std Dev 1021
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006 Mean 7835
Std Dev 8687
Mean 8607
Std Dev 961
Mean 8559
Std Dev 9863
Mean 8753
Std Dev 1022
240 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (smaller dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 7462
Std Dev 1021
Mean 7329
Std Dev 1066
Mean 762
Std Dev 1063
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006
Mean 79
Std Dev 8493
Mean 8524
Std Dev 9191
Mean 8455
Std Dev 9747
Mean 8732
Std Dev 1004
365 GeV qqqqrarrWW
5C kinematic fit4C kinematic fit4C rescalingRaw Mass
Marina Beguin W study at FCC-ee November 18 2019 2 7
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
W mass distributions - Semi leptonic channel
Marina Beguin W study at FCC-ee November 18 2019 3 7
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
Cross-section for different processes in lepton collisions
Marina Beguin W study at FCC-ee November 18 2019 4 7
All processes with larger orrelatively close cross-section tothe WW cross-section arepotential backgrounds for theWW decay study
sou
rce
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
Colour Reconnection - Models
Jesper Roy Christiansen July 23 2015EPS HEP Vienna
Color Reconnection (CR) in-teraction between partons ofthe two Ws
e+eminus rarrWW rarr q1q2q3q4
Because WW separation in phase-space issmaller than the typical distance scale of hadro-nisation (q1q4) and (q3q2)
Models in Pythia for e+eminus collisions are basedon string hadronisation
SK1 string = cylindrical bag Colourreconnection probability proportional tothe integrated overlap between cylinders
SK2 string = vortex line Colourreconnection if the cores are crossing
Marina Beguin W study at FCC-ee November 18 2019 5 7
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
Cone reconstruction effect on W mass resolution
Marina Beguin W study at FCC-ee November 18 2019 6 7
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
0005
001
0015
002
0025
003
0035
004
0045Mean 8302
Std Dev 7524
Mean 8301
Std Dev 7751
Wo treatment
Cone 04 rad
1626 GeVshift wo cone = 001517 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
Mean 8238
Std Dev 9568
Mean 8085
Std Dev 1026
Wo treatment
Cone 04 rad
240 GeVshift wo cone = 153515 GeV
40 50 60 70 80 90 100 110 120 (larger dijet mass) [GeV]WM
0
001
002
003
004
005
006Mean 8217
Std Dev 1014
Mean 7958
Std Dev 122
Wo treatment
Cone 04 rad
365 GeVshift wo cone = 259273 GeV
The loss of particle information degrades the resolution by 29 at1626 GeV 67 at 240 GeV and 169 at 365 GeV
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
Cone effect on ∆MW stat
radics [GeV] 1626 240 365
∆MW stat [MeV] standard cone standard cone standard conewoFSI 114 118 0215 0228 0463 0564
SKI 118 121 0225 0244 0478 055SKII 117 119 0218 0237 0467 0539BEC 117 118 0224 0236 0461 058
Marina Beguin W study at FCC-ee November 18 2019 7 7
∆MW stat is degraded with the cone by few percent atthreshold and 10-15 above
Full FCC-ee luminosity
- Appendix
-
