Working Group 3 Summary: V td , V ts , and Friends
description
Transcript of Working Group 3 Summary: V td , V ts , and Friends
Working Group 3 Summary:Working Group 3 Summary:VVtdtd, V, Vtsts, and Friends, and Friends
Jeffrey BerryhillLaurent Lellouch
Mikolaj MisiakChristoph Paus
CKM Workshop, UCSDMarch 18, 2005
K Bs B
2
Buchalla
Theoretically “Gold-Plated”relations of BFs to t = Vtd Vts*
KK++→ → rate ~ |Vrate ~ |VtdtdVVtsts*|*|22
Theory error in |VTheory error in |Vtdtd| extraction from BF ~10%| extraction from BF ~10%mostly parametric errors from mmostly parametric errors from mcc, V, Vcbcb
Only 5% error from scale dependence Only 5% error from scale dependence
KKLL → →rate ~ (Im rate ~ (Im tt))2 2 ~ ~ 22
Theory error in Theory error in extraction extraction from BF ~3%from BF ~3%
VVtdtdVVtsts* from Rare K Decays: K* from Rare K Decays: K++→→ , K, KLL
→→
K
et al.
3
KK+→ K+→ Measurement Measurement
StatusStatus
Blind analysis3 candidate events in the signal boxBackground probability = 0.001 (>3)
Jaffe
BNL E787/E949: Stop kaon, measure outgoing pionAggressively and redundantlyveto huge backgrounds
No new data expected15% precision improvement from final analysis
SM
4
Rare K Decays: SummaryRare K Decays: Summary
K
Interesting SM-like precisionis years away
K+ signal in the right range
5
K KK00 Mixing: Theory Precision Mixing: Theory Precision
6
K
7
Bs
8
9
10
Bs Mixing Measurements
Amplitude scanFit D*A*cos(m t) at fixed mExpect A=1 for real m, 0 otherwiseSensitivity: m such that 1.645A =1
95% CL: m such that A+1.645A = 1
CKM fits expect ms ≈ 14-24 ps-1
Bs
World average“Amplitude scan”ms > 14.5 ps-1
11
DØ Bs Mixing in Semileptonics
Limit: ms > 5.0ps–1 @95% CLSensitivity: 4.6 ps–1
Bs• BsDs X (460 pb–1)
– Ds – Enhanced opposite side
tag
– 7037 events (376 tags) D2=(1.170.04)%
Abbott
12
CDF Bs Mixing in Semileptonics
• BsDs + lepton (e/)– Ds , K*K, – 4355 events – Trigger: 4GeV e/ + track– Opposite side flavor tagse,,jetchargeD2=(1.430.09)%
Limit: ms > 7.7ps–1 @95% CLSensitivity: 7.3 ps–1
Bs
For both CDF+D0, semileptonic decaysrapidly lose ct resolution at realistic ms
Furic
13
CDF Hadronic B decays
FuricBs
14
Bs Mixing, Roadmap to Improvement
• More integrated luminosity• Better flavor tagging (same-side K tag)• Improve proper time
resolution (event-by-event vertexing)• Hadronic decays matter
more for larger ms
• D0 tracking upgrade (add small radius silicon this summer)
• DAQ/trigger/offline upgrades
• Peril: can present trigger efficiency be maintained at high instantaneous luminosity?
Bs Abbott
D0 projections
15
Friends of BFriends of Bss mixing: leptonic mixing: leptonic D decaysD decaysBs Ryd
CLEO-c measurement of D+ mn
Extract f(D+) from D+→decay rate
30k fully reconstructed ’’→ D+D- events8 signal events with missing mass = 0
Can improve to 3% precision for f(D+)
f(Ds+) 2% precision expected from
(3770)→Ds+ Ds
- running ( and )
CLEO-c
BF(DBF(D++→ → ) = 3.5 ± 1.4 ± 0.6 10) = 3.5 ± 1.4 ± 0.6 10-4-4
f(Df(D++) = 202 ) = 202 ± ± 41 41 ± ± 17 MeV17 MeVLAT = 225 LAT = 225 ± ± 13 13 ± ± 21 MeV21 MeVD decay constants and their ratiosD decay constants and their ratioscheck or bound errors of latticecheck or bound errors of latticeestimates of B decay constantsestimates of B decay constants
16
Friends of BFriends of Bss Mixing: B mixing and lifetime Mixing: B mixing and lifetimeBs
Mixing and lifetimes from B factoriescould ultimately improve by another 2x
HFAG average
Asymmetryvs. |t|
Further improvement in B0, B+ lifetime and B0 mixing fromB factories
Hastings
< 1% B factory precisionon lifetime and mixing
BelleD*lhadronic
BelleD*lhadronic
17
18
19
Friends of BFriends of Bss Mixing: recent lifetimes Mixing: recent lifetimes
progressprogress
BsAbbott
ss : new D0 measurement consistent with predictions• New DØ result
s/s=0.21 +0.33-0.45(stat.+syst.)
• Constrain Bs=1.39 ps
s/s=0.23+0.16-0.17(stat.+syst.)
Tarantino
Recent predictions and measurements exhibit no serious “lifetime puzzle”
HFAG measurements
Predictions
20
Radiative Penguin
Radiative B decays : penguin diagramSensitive to New Physics
b s process has been studied. Branching fraction. Charge and isospin asymmetry. Mixing induced CP asymmtery.
But, b d is not observed yet. ● suppressed by
|Vtd
/ Vts|2 in SM.
● Search for B, has been done.
~ 0.04
B Nishida
21
Search for B , BSearch for B+ +
, B0 0 , B0 Isospin relation
B(B (,) ) B(B++ ) = 2(B+/B0)B(B00 )= 2(B+/B0)B(B0 )
SM prediction: B(B (,) ) = (0.9-1.8) × 10-6
Analysis●Severe continuum background.●b s (esp. B K* ) background.●Non-negligible BB background.
Simultaneous fit to 3 modes (+B K* )
B Nishida
22
bb dd Branching Fractions: Branching Fractions: ExclusiveExclusive
central value 90% C.L. upper limit
B
Combined significance Belle+BaBar = 2.6
5 observation in 1-2 years
Nishida
23
BBosch
24
B Bosch
Inclusive ratio b →d /b →sbetter theory errors for Vtd/Vts, but might need SuperB factory
25
BFriends of Friends of , K*, K*: Other : Other
PenguinsPenguinsOther Penguin Decays
Hollar, Feldmann
B →K(*)ll, s ll branching fractionsmeasured by B factories and theory error already dominant
More will be learned from distributionsand asymmetries
B→ ll has possibility for observation at B factories(not background limited) ll much harder
26
ChallengesChallenges
A list of future challenges to the Workshop participants.
27
ChallengesChallenges
To the Tevatron: Now that you have a good shovel,break substantial new ground with it for ms constraints.
Bs
Upgrades, better tagging, better vertexing, more luminosity, better DAQ, Whatever it takes! The flavor physics community is cheering you on!
28
Challenges Challenges
To the Lattice community: Raise the “letter grade”above “C” level for fB, BB et al., so that the impactof future Tevatron results is maximized.
Bs
Andreas Kronfeld
To CLEO-c et al.: Continue to keep the lattice community honest!
29
Challenges Challenges
To the B factories: Measure a clear signal for B→or drive lower limit off the (CKM) map!
B
30
Challenges Challenges
To the heavy quark theory community: Improve and/or realistically bound the impact of penguinson Vtd/Vts et al. The measurements are there andready to be exploited now!
B
31
Challenges Challenges
To the Kaon physics community: Keep your future projects alive (and Andrzej out of retirement). The small theory errors mean these may ultimately bethe best attainable CKM constraints on Vtd and .
K