India CMS Mee+ng, BARC, Mumbai03/08/12 -‐ 04/08/12
Sudha Ahuja Brajesh Choudhary
University of Delhi, Delhi, India
Outline Published Results: QCD-‐10-‐019, QCD-‐10-‐035 and QCD-‐10-‐037
‣About QCD-‐10-‐037‣About QCD-‐11-‐005 (ongoing)
• Inputs for the measurement• Efficiency Study• Purity esOmaOon• Unfolding• Comparison with theoreOcal predicOons.
Summary & Plans1
UPDATE: Study of Direct Photons at CMS
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
QCD-‐10-‐019First publicaOon with photons21 < ETγ < 300 GeV & |ηγ| < 1.45. Measurement using cluster shape of the photon.Phys. Rev. Le^. 106, 082001 (2011)
2
Inclusive Photon Measurements:
!
Ldt = 2.9pb"1#
!
Ldt = 36pb"1#
QCD-‐10-‐037 (Details in coming slides)Covers 25 < ETγ
< 400 GeV & |ηγ | < 2.5Measurement using Conversion (low ET range) and IsolaOon (high ET range)Phys. Rev. D 84, 052011 (2011)
QCD-‐10-‐035ETγ
1 > 23 GeV & ETγ2 > 20 GeV with ΔR(γ1, γ2) > 0.45
|ηγ1,γ 2| < 2.5 excluding 1.45 < |ηγ1, γ2| < 1.57Signal & background shapes extracted using ECAL isolaOon variable JHEP01 (2012) 133
Diphoton Measurements:
!
Ldt = 36pb"1#
Published Results
QCD-10-019: arXiv:1012.0799 CERN-PH-EP-2010-053 Phys. Rev. Lett. 106 (2011) 082001
First prompt photon measurement from the LHC: dσ/dET for |η|<1.45, ET>21 GeV, 2.9pb-1
EM shower shape used to estimate signal fraction
Comparison to pQCD calculation: JETPHOX (JHEP 0205:028,2002, Phys.Rev. D73:094007,2006, Phys.Rev. D79:114024,2009 )
Differential Cross Sections: γ + XQCD-10-019 and QCD-10-037
C.M. Kuo, V. Chetluru, S.L.Linn, C.Lin, D. d'Enterria, S-S. Yu, S. Ganjour, S. Ahuja, B. Choudhary, S.W. Li, Z.K. Liu, Y.J. Lu, D. Mekterovic, R.S. Lu, V. Gaultney Werner, Y. Kim, Y.J. Lee, C. Jessop, T. Kolberg, N. Marinelli, J. Branson, C. Palmer, M. Pieri, M.Sani, M.Anderson, K. Ocalan, A. Bornheim,M. Gataullin, J. Veverka
http://cms.cern.ch/iCMS/analysisadmin/cadi?ancode=QCD-10-019
3
QCD-10-037: Phys. Rev. D 84, 052011 (2011) R. Tenchini: ‘our record in speed for PRD’ https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsQCD10037
Acceptance extended to dσ/dET for |η|<2.5 in 4 bins, 25 GeV<ET<400 GeV, 35.9 pb-1
Differential Cross Sections: γ + XQCD-10-037
Combined photon Isolation and Converted photon E/p used to estimate signal fraction
Comparison to pQCD calculation: JETPHOX (JHEP 0205:028,2002, Phys.Rev. D73:094007,2006, Phys.Rev. D79:114024,2009 )
C.M. Kuo, V. Chetluru, S.L.Linn, C.Lin, D. d'Enterria, S-S. Yu, S. Ganjour, S. Ahuja, B. Choudhary, S.W. Li, Z.K. Liu, Y.J. Lu, D. Mekterovic, R.S. Lu, V. Gaultney Werner, Y. Kim, Y.J. Lee, C. Jessop, T. Kolberg, N. Marinelli, J. Branson, C. Palmer, M. Pieri, M.Sani, M.Anderson, K. Ocalan,A. Bornheim,M. Gataullin, J. Veverka
QCD-10-035: Answers to CWR comments prepared, ready for discussion with ARC
dσ/dQ for Q={mγγ, ptγγ, Δφγγ, cosθ*}, ET >{20, 23 GeV}, |η|<1.44 and |η|<2.5, ΔR(γγ)>0.45, 36pb-1
ECAL isolation variable used to estimate signal fraction
Compared to pQCD predictions to order αsα2: DIPHOX (Binoth, Guillet, Pilon, Werlen) with gamma2MC (Bern,Dixon, Schmidt)
Differential Cross Sections: γγ + XQCD-10-035
S. Ahuja, O. Bondu, H. Brun, N.Chanon, G. Chen, B. Choudhary, M. Dejardin, D. D’Enterria, J. Fan, F. Ferri, S. Gascon-Shotkin, P. Gras, M. Lethuillier, J. Malcles, L. Millischer, J. Tao, H. Xiao
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
QCD-‐10-‐019• Studied the MC efficiencies for the analysis:
using the loose and the Oght photon ID cuts for the various templates used in the analysis (given below)
๏ Efficiency for Reco Photon matched with a Generated Photon & with GenIso < 5 GeV + ๏ hadronic/EM fracOon < 0.05 && < 0.01 (barrel) OR ESRaOo > 0.1 (endcaps)๏ hadronic/EM fracOon < 0.05 && combined IsolaOon < 5.0 GeV ๏ hadronic/EM fracOon < 0.05 && Track IsolaOon < (2.0 + 0.001* PTγ) GeV && Ecal IsolaOon<
(4.2 + 0.003* PTγ) GeV && Hcal IsolaOon < (2.2 + 0.001* PTγ) GeV
6
QCD-‐10-‐035• Studied the theoreOcal predicOons using Sherpa
• Requirements on photon
ContribuOons
๏ Number of γ ≥ 2 ๏ PTγ
1 > 21 GeV
๏ PTγ2 > 20 GeV
๏ |ηγ1 , γ2| < 2.5
๏ Exclude 1.442 < |ηγ1 , γ2| < 1.556๏ Generator level Iso (γ1) < 5 GeV๏ Generator level Iso (γ2) < 5 GeV๏ ΔR (γ1 & γ2) ≥ 0.45
!
"i#i#
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai 7
• Second measurement on inclusive photons in CMS (using full 2010 dataset)
• Covers range 25 < ETγ < 400 GeV & extended up to endcaps: |ηγ | < 2.5
• Measurement divided in 4 photon pseudo-‐rapidity ranges (differenOal) 0.0 < |ηγ | < 0.9 , 0.9 < |ηγ | < 1.44 , 1.57 < |ηγ | 2.1 & 2.1 < |ηγ | < 2.5
• Measurement using Conversion method for low ET range / IsolaOon for high ET range
• Signal and Background discriminaOng variables:
Conversion Method: ET/pT (energy in ECAL / transverse momentum of e+e-‐ pair in tracker)
IsolaOon Method: Iso = IsoTRK + IsoECAL +IsoHCAL
• Weighted average of differenOal cross secOon measured with the two methods reported
• DifferenOal cross secOon is given as:
where-‐ Nγ – signal photon yield-‐ U – bin by bin unfolding correcOons-‐ L – integrated luminosity-‐ ε – product of reco, ID & trigger efficiencies -‐ ΔΕΤγ – ETγ bin; Δηγ – ηγ bin
QCD-‐10-‐037 (I)
!
Ldt = 36pb"1#
Tes
T
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai 8
• Photon ID requirements:
• ContribuOon: HLT matching criterion studies using the ΔR(HLT object,γ) and ΔET(HLT object,γ)/ET variables. Trigger efficiency studies using the raOos of independent trigger paths. Documented in AN-‐10-‐458: “Photon Plus Jet: Single Photon HLT path efficiency measurements
for the 2010 dataset”. Analysis with 2010 data
QCD-‐10-‐037 (II)
T/pTE
0 0.5 1 1.5 2 2.5 3
Events/0.097
0
100
200
300
400
500
T/pTE
0 0.5 1 1.5 2 2.5 3
Events/0.097
0
100
200
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Data
Fitted bkg.
Fit result
| < 0.9!| < 30 GeVT25 < E
-1 = 2.4 pbintL = 7 TeVsCMS (a)
ISO [GeV]0 5 10 15 20
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V
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DataFit to dataSignalBackground
(a) = 7TeVsCMS
<100 GeVT80 <E|<0.9 ", |-1 = 36 pbintL
candidate)! R(HLT object,"0 1 2 3 4 5 6 7 8 9
-610
-510
-410
-310
-210
-110
1 HLT_Photon20_Cleaned_L1RHLT_Photon30_Cleaned_L1RHLT_Photon50_Cleaned_L1R_v1HLT_Photon70_Cleaned_L1R_v1
s = 7 TeV#
candidates : All!
-1 candidate!
T/pHLT object
Tp
-1 0 1 2 3 4 5 6 7
-510
-410
-310
-210
-110
1 HLT_Photon20_Cleaned_L1RHLT_Photon30_Cleaned_L1RHLT_Photon50_Cleaned_L1R_v1HLT_Photon70_Cleaned_L1R_v1
s = 7 TeV"
candidates : All!
[GeV]T
p45 50 55 60 65 70 75 80 85 90 95
Effi
cien
cy
0
0.2
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0.8
1
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1.6HLT_Photon50_Cleaned_L1R_v1HLT_Photon70_Cleaned_L1R_v1
IsoCuts I
s = 7 TeV!
CMS Preliminary|<1.444"|
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai 9
QCD-‐10-‐037 (III)
[GeV]TE30 40 50 210 210!2
[nb/
GeV]
"d T/d
E#2 d
-510
-210
10
410
710810 + X $ %p + p
JETPHOX)6| < 2.5 ( X 10"2.1 < |
)4| < 2.1 ( X 10"1.57 < |)2| < 1.44 ( X 10"0.9 < |
| < 0.9"|
NLO pQCD JETPHOX
T=ERµ=
fµ=
FµCT10 / BFG II,
MPI and hadronization corrected
< 5 GeVisoT
, E-1 = 36 pbintL = 7 TeVsCMS
[GeV]TE30 40 210 210!2
Data
/The
ory
0.0
0.5
1.0
1.5
2.0
Data / JETPHOX CT10Stat. + syst. uncertaintyScale uncertainty
uncertaintys" #CT10 PDF
-1 = 36 pbint = 7 TeV, LsCMS (a) < 5 GeViso
T| < 0.9, E$|
[GeV]TE30 40 210 210!2
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/The
ory
0.0
0.5
1.0
1.5
2.0
Data / JETPHOX CT10Stat. + syst. uncertaintyScale uncertainty
uncertaintys" #CT10 PDF
-1 = 36 pbint = 7 TeV, LsCMS (b) < 5 GeViso
T| < 1.44, E$0.9 < |
[GeV]TE30 40 210 210!2
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/The
ory
0.0
0.5
1.0
1.5
2.0
Data / JETPHOX CT10Stat. + syst. uncertaintyScale uncertainty
uncertaintys" #CT10 PDF
-1 = 36 pbint = 7 TeV, LsCMS (c) < 5 GeViso
T| < 2.1, E$1.57 < |
[GeV]TE30 40 210 210!2
Data
/The
ory
0.0
0.5
1.0
1.5
2.0
Data / JETPHOX CT10Stat. + syst. uncertaintyScale uncertainty
uncertaintys" #CT10 PDF
-1 = 36 pbint = 7 TeV, LsCMS (d) < 5 GeViso
T| < 2.5, E$2.1 < |
Ratios of the measured isolated prompt photon differentialcross section to the NLO pQCD predictions
Predictions from the NLO pQCD calculations are consistent with the measured cross sections within uncertainities. The measurement establishes a benchmark for photon identification & background estimation.It determines the rate of one of the background processes affecting new physics.
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
h@ps://twiki.cern.ch/twiki/bin/view/CMS/QCDGammaPlusJetQCD11005
10
Vasundhara Chetluru, Brajesh Choudhary, A. Murat Guler, Bob Hirosky, Chuanzhe Lin, Darko Mekterovic, Kadir Ocalan, Sudha Ahuja
Validate perturbative QCD.
Constrain PDFs of the proton.
Reducible background to H → γγ.
Background for many new physics searches such as SUSY, extra dimensions, quark compositeness…
Serves as a reference to similar measurements in heavy ion collisions.
QCD-‐11-‐005: “Measurement for the Triple-differential-cross-section for γ + Jets”
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
• Measurement of triple-‐differenOal-‐cross-‐secOon for events with at least a photon & a jet in various ETγ , ηγ & ηJet bins
• Binnings: ETγ (GeV): 40-‐45, 45-‐50, 50-‐60, 60-‐70, 70-‐85, 85-‐100, 100-‐145, 145-‐300
|ηγ |: 0-‐0.9, 0.9-‐1.4442, 1.566-‐2.1, 2.1-‐2.5 |ηJet|: 0-‐1.5, 1.5-‐2.5
• Analysis: Efficiency measurement, Purity esOmaOon, Unfolding & Comparison with theoreOcal predicOons.
• Comparison with theory: JETPHOX, SHERPA & PYTHIA • Triple-‐differenOal-‐cross-‐secOon calculated using:
11
!
Ldt = 2.19 fb"1#
where,
!
d3"# ,isolateddET
# d$#d$Jet =1
%ET# %$#%$Jet U
NYield#
L *&
QCD-‐11-‐005: “Measurement for the Triple-differential-cross-section for γ + Jets”
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
MC Samples Used: (complete list in Back-‐up)‣ PYTHIA Summer11 γ + Jet Z2 tune‣ PYTHIA Summer11 QCD di-‐jet Z2 tune‣ Madgraph γ + Jet
Datasets Run rangeRecorded Luminosity
(pb-‐1)
/Photon/Run2011A-‐May10ReReco-‐v1/AOD 160431-‐163869 216.204
/Photon/Run2011A-‐PromptReco-‐v4/AOD 165088-‐167913 934.059
/Photon/Run2011A-‐05Aug2011-‐v1/AOD 170722-‐172619 373.349
/Photon/Run2011A-‐PromptReco-‐v6/AOD 172620-‐173692 667.180
2011 Datasets used:
Corresponding JSON files used:May10ReReco-‐v1 -‐ Cert_160404-‐163869_7TeV_May10ReReco_Collisions11_JSON_v3.txt
PromptReco-‐v4 & v6 -‐ Cert_160404-‐177053_7TeV_PromptReco_Collisions11_JSON.txt
05Aug2011-‐v1 -‐ Cert_170249-‐172619_7TeV_ReReco5Aug_Collisions11_JSON_v2.txt
12
INPUTS for the Measurement (I)
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
Trigger Paths Used:
HLT trigger path Run rangeRecorded
Luminosity (Eff.)(pb-‐1)
EventspT range (GeV)
HLT_Photon30_CaloIdVL_v1-‐7 160431-‐173692 2190.8 (3.53) 1208139 40-‐60
HLT_Photon30_CaloIdVL_v1-‐3HLT_Photon50_CaloIdVL_v1-‐4
160431-‐165087165088-‐173692 2190.8 (11.67) 1231920 60-‐85
HLT_Photon75_CaloIdVL_v1-‐7 160431-‐173692 2190.8 (276.93) 1756132 85-‐100
HLT_Photon75_CaloIdVL_v1-‐3 HLT_Photon90_CaloIdVL_v1-‐4
160431-‐165087165088-‐173692 2190.8 (361.80) 1844488 100-‐145
HLT_Photon75_CaloIdVL_v1-‐3HLT_Photon125_v1-‐2HLT_Photon135_v1-‐2
160431-‐165087165088-‐166967167039-‐173692
2190.8 (2190.6) 1220065 145-‐300
13
INPUTS for the Measurement (II)
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
Physics Objects Used:
‣ Photon -‐ reco photons
‣ Photon ID Cuts: • hadronic/EM fraction (H/E < 0.05)
• Shower shape (Barrel) ( < 0.010)
• Shower shape (Endcaps) ( < 0.028)
• No pixel seed required
‣ Jet -‐ AK5 pfJets
‣ Jet ID Cuts: • Neutral hadron frac+on < 0.99
• Neutral EM frac+on < 0.99
• Number of Cons+tuents > 1
• For η < 2.4 and η > -‐2.4,
• Charged hadron frac+on > 0
• Charged mul+plicity > 0
• Charged EM frac+on < 0.99
• Residual jet energy correc+ons applied
• ΔR(γ,Jet) > 0.50
!
"i#i#
!
"i#i#
14
INPUTS for the Measurement (III)
‣ Side band SelecOon Cuts: • hadronic/EM fraction (H/E < 0.05)
• Shower shape (Barrel) (0.011 < < 0.015)
• Shower shape (Endcaps) (0.035 < < 0.040)
• No pixel seed required
!
"i#i#
!
"i#i#
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
‣ HLT Efficiency (εTrigger): ๏ Data driven, using Tag & Probe
๏ Tag -‐ Electron passing VBTF WP80 ID, PT > 20 GeV, passing single/double electron trigger
๏ Probe -‐ Electron passing offline photon ID, PT > 20 GeV, passing single photon HLT
๏ Pair selec+on -‐ exclude transi+on gap and consider mass window 60 GeV < MZ < 120 GeV.
๏ RaOo technique -‐ using ra+o of independent prescaled trigger paths.
‣ ReconstrucOon efficiency (εRECO):๏ Using simulaOon (PYTHIA)
๏ Eff = Generated Photons matched to a Reconstructed Photon
๏ Generator level isola+on < 5.0 GeV
๏ Efficiency almost 98 -‐ 99 %
) (GeV/c)!(T
p50 60 70 80 90 100 110 120 130 140
Eff
icie
ncy
0
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)"!(T
A RooPlot of "pCMS Preliminary 2011 = 7 TeVs
-1L dt= 216 pb"HLT_Photon75_CaloIdVL
(GeV/c)T
GEN Photon p50 100 150 200 250 300
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CO
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icie
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)|<0.9!("|
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)|<2.5!("2.1<|
CMS = 7 TeVs
15
All Generated Photons
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icie
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y
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HLT_Photon50_CaloIdVLHLT_Photon75_CaloIdVL
s = 7 TeV!CMS
Efficiency Measurement (ε = εTrigger×εRECO×εID×εPMV) (I)
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
‣ ID Efficiency (εID): (photon ID as given on slide 8)๏ Using both data and simulaOon
๏ Eff = Reconstructed Photons passing photon ID
๏ Difference in MC and data is reported as systema+c uncertainity
‣ Pixel Match Veto Efficiency (εPMV):๏ Inherited from a previous analysis (CMS AN-‐2012-‐043)
๏ Probability for a reconstructed signal photon not to match any reconstructed track in the pixel detector that is consistent with a primary vertex
(GeV/c)T
RECO Photon p50 100 150 200 250 300
ID E
ffic
ienc
y
0.75
0.80
0.85
0.90
0.95
1.00
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CMS = 7 TeVs
16
All Reconstructed Photons
Efficiency Measurement (ε = εTrigger×εRECO×εID×εPMV) (II)
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
• IsolaOon Template Used for the measurement:
‣ IsolaOon = (Tracker + ECAL + HCAL) isolaOon
• Signal Template -‐ Obtained from PYTHIA γ+jet MC using Gaussian convoluted with lifeOme funcOon
• Background Template -‐ Obtained from DATA sideband selecOon using inverted ARGUS funcOon
• Signal + Background Template -‐ fit to DATA template w i t h S u m ( I s o ) = N S S ( I s o ) + N B B ( I s o ) [NS -‐ esOmated # of signal events & NB -‐ esOmated # of background events]
• Pile-‐Up reweighOng: Reweight # of pileup interacOon from the simulaOon truth to the target pileup distribuOon for data
17
Purity EsOmaOon (I)
!""#
$#
%&'&#
()*+&,#
-&./*012+3#
Isolation (GeV)0 5 10 15 20 25 30
Even
ts /
( 0.5
)0
500
1000
1500
2000
2500
3000
3500CMS 2011
= 7 TeVs < 100 GeVT
!85 GeV < E| < 0.9000!"0.0000 < |
| < 1.5jet"0.0 < |
Data
Signal Component
Background Component
Fitting Result
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
• SystemaOcs (All uncertainiOes added in quadrature)‣ Uncertainity on Signal Template from γ+jet MC:
Study signal template of photon objects between Z→μμγ MC and Data events. Fit results from MC and data using the signal template fi�ng funcOon match very well. Difference in value of purity obtained by varying fi�ng parameter up & down is quoted as uncertainity.
‣ Uncertainity on Background Template: Uncertainity due to mis-‐match between sideband and signal like selecOon in QCD events, evaluated using pseudo experiment.
18
Purity EsOmaOon (II)
(GeV)T
p!50 100 150 200 250 300
Pur
ity
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1 CMS 2011 preliminary = 7 TeVs
| < 0.9!"0 < |
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| < 2.5jet"1.5 < |
(GeV)T
p!50 100 150 200 250 300
Pur
ity
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1 CMS 2011 preliminary = 7 TeVs
| < 1.4442!"0.9 < |
| < 1.5jet"0.0 < |
| < 2.5jet"1.5 < |
(GeV)T
p!50 100 150 200 250 300
Pur
ity
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1 CMS 2011 preliminary = 7 TeVs
| < 2.1!"1.566 < |
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| < 2.5jet"1.5 < |
(GeV)T
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Pur
ity
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1 CMS 2011 preliminary = 7 TeVs
| < 2.5!"2.1 < |
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| < 2.5jet"1.5 < |
Purity results
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
• For every differenOal measurement a mapping between measured and true values of the variables has to be evaluated
• In our case 3D unfolding (black: bins used for measurement; red: addiOonal bins used for unfolding):
PTγ : 30-‐40, 40-‐45, 45-‐50, 50-‐60, 60-‐70, 70-‐85, 85-‐100, 100-‐145, 145-‐300, 300-‐500 GeV
|ηγ |: 0-‐0.9, 0.9-‐1.4442, 1.4442-‐1.566, 1.566-‐2.1, 2.1-‐2.5, 2.5-‐2.6
|ηJet|: 0-‐1.5, 1.5-‐2.5, 2.5-‐2.7
• IteraOve (Bayesian) method is employed
• Result consistent with results from bin by bin correcOon method
• UncertainiOes:
“StaOsOcal”, due to the limited size of MC samples
Due to the difference in shape between data and MC distribuOons
Due to the difference in efficiency between data and MC
19
UNFOLDING
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai 20
๏ JETPHOX
• Program to calculate the reacOons hadron hadron → gamma/hadron + jet + X.• Evaluates cross secOon at NLO accuracy
๏ SHERPA: “SimulaOon of High Energy ReacOons of ParOcles”.
‣ Leading order 2→n hard process generator.
‣ Inbuilt matrix-‐element generators: Comix -‐ default large mulOplicity matrix element generator.
‣ Provides completely unweighted, inclusive and fully hadronized final states.
‣ Main feature’s of Sherpa:
• Provides a be^er descripOon of mulOjets processes.
• Similar technique also extended to the processes involving hard photons. “DemocraOc” extension of QCD ME+PS merging to QED. (Reference -‐ S. Hoche and S. Schumann and F. Siegert, Hard photon producOon and matrix-‐element parton-‐shower merging, Phys. Rev. D81 (2010) 034026 [arXiv:0912.3501]).
• Provides an improved descripOon of Tevatron direct photon measurements.
TheoreOcal PredicOons: JETPHOX/ SHERPA
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
• Studied the following sources of uncertainiOes:
‣ Scale uncertainiOes
• varied the default values of renormalizaOon(μR) & factorizaOon(μF) scales in range around [1/2,2]
๏ μR = 1/2μR & μF = μF; μR = 1/2μR & μF = 2μF;
๏ μR = μR & μF = 1/2μF; μR = μR & μF = 2μF;
๏ μR = 2μR & μF = μF; μR = 2μR & μF = 1/2μF;
‣ PDF uncertainiOes
• varied PDF sets from the default PDF set
• uncertainity from within error sets in a single PDF
21
SystemaOcs for TheoreOcal predicOons
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
Results are compared to JETPHOX and SHERPA.
Results are binned in the four photon pseudorapidity regions and two jet pseudorapidity regions under study.
22
Triple-‐differenOal-‐cross-‐secOon (DATA/ SHERPA/ JETPHOX)
‣ Values from Jetphox and Sherpa are close enough. ‣ In low PTγ bins there is dis-‐agreement between the Data and predicOons.
‣ In some high PTγ bins in Endcaps, Sherpa is closer to Data than Jetphox.
(GeV)!
Tp
40 50 60 70 80 210 210"2 210"3
jet
#d! #d! T/d
p$3 d
-210
-110
1
10
210
310
410
510
610
710
810
910
| < 1.5jet#|
CMS Preliminary s = 7 TeV%
JETPHOXSHERPA
| < 0.9!#|)2| < 1.4442 (X10!#0.9 < |
)4| < 2.1 (X10!#1.566 < |)6| < 2.5 (X10!#2.1 < |
(GeV)!
Tp
40 50 60 70 80 210 210"2 210"3
jet
#d! #d! T/d
p$3 d
-310
-210
-110
1
10
210
310
410
510
610
710
810
910
| < 2.5jet#1.5 < |
CMS Preliminary s = 7 TeV%
JETPHOXSHERPA
| < 0.9!#|)2| < 1.4442 (X10!#0.9 < |
)4| < 2.1 (X10!#1.566 < |)6| < 2.5 (X10!#2.1 < |
ObservaOons:
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai 23
RaOos of Triple-‐differenOal-‐cross-‐secOon (DATA/ SHERPA)
Sherpa follows similar pa^ern as Data in most of the regions.
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
• “Inclusive photon” (QCD-‐10-‐019 & QCD-‐10-‐037) and “Diphoton” (QCD-‐10-‐035)analysis published in CMS upto now. (Significant contribu.on in QCD-‐10-‐037)
• The current ongoing analysis is QCD-‐11-‐005, “Measurement of the γ+jet events” with 2.19 �-‐1 of data.
• QCD-‐11-‐005 is currently pre-‐approved inside the SMP group and is in compleOon stage of the ARC reviewal process. It will be going for approval soon when ARC gives the green light.
• Plan to complete the reviewal process of QCD-‐11-‐005 and get it approved.• Thesis Structure: Plan a thesis based on QCD-‐10-‐037 (Inclusive Photon
measurement) and QCD-‐11-‐005 (γ + Jets measurement).
24
STATUS & PLANS
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai
• Shi�s: (January-‐June) Took 4 weeks of shi�s as ECAL PFG expert
• Online Z peak calibraOon perform an offline study on electron/photon enriched datasets a�er applying the eID cuts
resolve the Z peak offline using ECAL informaOon only
check the feasibility of the study -‐ Enough staOsOcs to resolve Z peak
calibrate the Z peak in the online DQM with similar set of ECAL only cuts available online
Also check for similar study with other parOcles -‐ π0 and J/ψ
• Status: (January-‐June) Feasibility and offline study ongoing
Move to online study and calibrate the Z peak
25
Service Work
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai 26
Back-‐UP
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai 27
Data/Theory with uncertainiOes
(GeV)!
Tp
40 50 60 70 80 90 210 210"2 210"3
data
/theo
ry
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
| < 2.5jet#1.5 < | | < 1.44!#0.9 < |
CMS Preliminary s = 7 TeV$
JETPHOX scale variation
JETPHOX PDF variation
(GeV)!
Tp
40 50 60 70 80 90 210 210"2 210"3
data
/theo
ry
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
| < 1.5jet#| | < 1.44!#0.9 < |
CMS Preliminary s = 7 TeV$
JETPHOX scale variation
JETPHOX PDF variation
(GeV)!
Tp
40 50 60 70 80 90 210 210"2 210"3
data
/theo
ry
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
| < 2.5jet#1.5 < | | < 0.9!#|
CMS Preliminary s = 7 TeV$
JETPHOX scale variation
JETPHOX PDF variation
(GeV)!
Tp
40 50 60 70 80 90 210 210"2 210"3
data
/theo
ry
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
| < 1.5jet#| | < 0.9!#|
CMS Preliminary s = 7 TeV$
JETPHOX scale variation
JETPHOX PDF variation
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai 28
Data/Theory with uncertainiOes
(GeV)!
Tp
40 50 60 70 80 90 210 210"2 210"3
data
/theo
ry
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
| < 2.5jet#1.5 < | | < 2.5!#2.1 < |
CMS Preliminary s = 7 TeV$
JETPHOX scale variation
JETPHOX PDF variation
(GeV)!
Tp
40 50 60 70 80 90 210 210"2 210"3
data
/theo
ry
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
| < 1.5jet#| | < 2.5!#2.1 < |
CMS Preliminary s = 7 TeV$
JETPHOX scale variation
JETPHOX PDF variation
(GeV)!
Tp
40 50 60 70 80 90 210 210"2 210"3
data
/theo
ry
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
| < 2.5jet#1.5 < | | < 2.1!#1.57 < |
CMS Preliminary s = 7 TeV$
JETPHOX scale variation
JETPHOX PDF variation
(GeV)!
Tp
40 50 60 70 80 90 210 210"2 210"3
data
/theo
ry
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
| < 1.5jet#| | < 2.1!#1.57 < |
CMS Preliminary s = 7 TeV$
JETPHOX scale variation
JETPHOX PDF variation
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai 29
List of MC Datasets
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai 30
jet in Barrel, opposite η side
jet in Endcap, opposite η sidejet in Endcap, same η side
γ
jet in Barrel, same η side
Tracker
ECALHCAL
|ηjet|<1.45, ηjetηγ>0 |ηjet|<1.45, ηjetηγ<0
1.55<|ηjet|<2.4, ηjetηγ >0 1.55<|ηjet|<2.4, ηjetηγ <0
γ
γ γ
• Different γ+jet orienta+ons (Similar orienta+ons used in D0 study)• Photon required to be in barrel
• Lead jet may be central or forward, and may same sign or opposite sign η to photon
DiagrammaOc View of the OrientaOons considered in raOos
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai 31
Efficiency Back up
03/08/12 -‐ 04/08/12 India CMS Mee+ng, BARC, Mumbai32
PileUp ReweighOng
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