Working Group 3 Summary: V td, V ts, and Friends Jeffrey Berryhill Laurent Lellouch Mikolaj Misiak Christoph Paus CKM Workshop, UCSD March 18, 2005 K BsBs B

2 Buchalla Theoretically “Gold-Plated” relations of BFs to t = V td V ts * K + →    rate ~ |V td V ts *| 2 Theory error in |V td | extraction from BF ~10% mostly parametric errors from m c, V cb Only 5% error from scale dependence K L →    rate ~ (Im t ) 2 ~  2 Theory error in  extraction from BF ~3% V td V ts * from Rare K Decays: K + →  , K L →   V td V ts * from Rare K Decays: K + →  , K L →   K et al.

3 K K+→    Measurement Status Blind analysis 3 candidate events in the signal box Background probability = (>3  ) Jaffe BNL E787/E949: Stop kaon, measure outgoing pion Aggressively and redundantly veto huge backgrounds No new data expected 15% precision improvement from final analysis SM

4 Rare K Decays: Summary K Interesting SM-like precision is years away K + signal in the right range

5 K K 0 Mixing: Theory Precision

6 K

7 BsBs

8

9

10 B s Mixing Measurements Amplitude scan  Fit D*A*cos(  m t) at fixed  m  Expect A=1 for real  m, 0 otherwise  Sensitivity:  m such that  A =1  95% CL:  m such that A  A = 1 CKM fits expect  m s ≈ ps -1 BsBs World average “Amplitude scan”  m s > 14.5 ps -1

11 DØ B s Mixing in Semileptonics Limit:  m s > 5.0ps CL Sensitivity: 4.6 ps –1 BsBs B s  D s  X (460 pb –1 ) –D s  –Enhanced opposite side  tag –7037 events (376 tags) –  D 2 =(1.17  0.04)% Abbott

12 CDF B s Mixing in Semileptonics B s  D s + lepton (e/  ) –D s , K*K,  –4355 events –Trigger: 4GeV e/  + track –Opposite side flavor tags e, ,jetcharge  D 2 =(1.43  0.09)% Limit:  m s > 7.7ps CL Sensitivity: 7.3 ps –1 BsBs For both CDF+D0, semileptonic decays rapidly lose ct resolution at realistic  m s Furic

13 CDF Hadronic B decays Furic BsBs

14 B s 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  m s D0 tracking upgrade (add small radius silicon this summer) DAQ/trigger/offline upgrades Peril: can present trigger efficiency be maintained at high instantaneous luminosity? BsBs Abbott D0 projections

15 Friends of B s mixing: leptonic D decays BsBs Ryd CLEO-c measurement of D+ mn Extract f(D + ) from D + →  decay rate 30k fully reconstructed  ’’→ D + D - events 8 signal events with missing mass = 0 Can improve to 3% precision for f(D + ) f(D s + ) 2% precision expected from  (3770)→D s + D s - running (  and  ) CLEO-c BF(D + →  ) = 3.5 ± 1.4 ± f(D + ) = 202 ± 41 ± 17 MeV LAT = 225 ± 13 ± 21 MeV D decay constants and their ratios check or bound errors of lattice estimates of B decay constants

16 Friends of B s Mixing: B mixing and lifetime BsBs Mixing and lifetimes from B factories could ultimately improve by another 2x HFAG average Asymmetry vs. |  t| Further improvement in B 0, B + lifetime and B 0 mixing from B factories Hastings < 1% B factory precision on lifetime and mixing Belle D* l  hadronic  Belle D* l  hadronic 

17

18

19 Friends of B s Mixing: recent lifetimes progress BsBs Abbott  s  s : new D0 measurement consistent with predictions New DØ result  s /  s = (stat.+syst.) Constrain  Bs =1.39 ps  s /  s = (stat.+syst.) Tarantino Recent predictions and measurements exhibit no serious “lifetime puzzle” HFAG measurements Predictions

20 Radiative Penguin Radiative B decays : penguin diagram Sensitive 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 |V td / V ts | 2 in SM. ● Search for B ,   has been done. ~ 0.04 B Nishida

21 Search for B , B  Search for B +   + , B 0   0 , B 0    Isospin relation B( B  ( ,  )  )  B (B +  +  ) = 2(  B + /  B 0 ) B (B 0  0  ) = 2(  B + /  B 0 ) B (B 0  ) SM prediction: B( B  ( ,  )  ) = ( ) × Analysis ● Severe continuum background. ● b  s  (esp. B  K *  ) background. ● Non-negligible BB background. Simultaneous fit to 3 modes (+ B  K *  ) B Nishida

22 b  d  Branching Fractions: Exclusive central value90% C.L. upper limit B Combined significance Belle+BaBar = 2.6  5  observation in 1-2 years Nishida

23 B Bosch

24 B Bosch Inclusive ratio b →d  /b →s  better theory errors for V td /V ts, but might need SuperB factory

25 B Friends of , K*  : Other Penguins Other Penguin Decays Hollar, Feldmann B →K(*)ll, s ll branching fractions measured by B factories and theory error already dominant More will be learned from distributions and asymmetries B→  ll has possibility for observation at B factories (not background limited)  ll much harder

26Challenges A list of future challenges to the Workshop participants.

27Challenges To the Tevatron: Now that you have a good shovel, break substantial new ground with it for  m s constraints. BsBs Upgrades, better tagging, better vertexing, more luminosity, better DAQ, Whatever it takes! The flavor physics community is cheering you on!

28Challenges To the Lattice community: Raise the “letter grade” above “C” level for f B, B B et al., so that the impact of future Tevatron results is maximized. BsBs Andreas Kronfeld To CLEO-c et al.: Continue to keep the lattice community honest!

29Challenges To the B factories: Measure a clear signal for B→  or drive lower limit off the (CKM) map! B

30Challenges To the heavy quark theory community: Improve and/or realistically bound the impact of penguins on V td /V ts et al. The measurements are there and ready to be exploited now! B

31Challenges To the Kaon physics community: Keep your future projects alive (and Andrzej out of retirement). The small theory errors mean these may ultimately be the best attainable CKM constraints on V td and . K