1 B Physics at CDF Junji Naganoma University of Tsukuba “New Developments of Flavor Physics“ Workshop Tennomaru, Aichi, Japan

2 B Physics at the Tevatron Complements excellent programs at B-factories Pros Large production cross section: All bottom hadrons are produced B +, B 0, B s, B c +,  b, … Cons Large combinatorics and messy events Difficult to detect low pT  and  0 ’s from B decays Inelastic cross section is a factor of 10 3 larger with roughly the same pT spectrum Difficult to trigger on B’s Phys. Rev. D 71, (2005) Measured in inclusive J/  events  = 17.6  0.4(stat) (syst.)  b 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

3 B Physics Results Discussed Today New results since last year’s workshop Production: X(3872) Lifetime: B c, B s,  b Rare Decay: B s  e+  - CP Violation: B s  J/  1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

4 X(3872) First observed by Belle collaboration in 2003 Confirmed by CDF, D0, and BaBar soon after Observed in decay X(3872)  J/  +  - Nature of particle is still unknown D*D “molecule”? 4-quark state? … Precise mass measurement can provide clues Observation of mass splitting offers evidence of tetra-quark state Absolute mass checks possibility of a D*D bound-state 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

5 X(3872) Mass M(X) =  0.16(stat)  0.19(syst) MeV/c 2 Result consistent with no mass splitting Assign upper limit:  m(X(3872)) < 3.6 MeV/c 95% C.L. World best measurement 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

6 Interests in B Hadron Lifetimes Test Heavy Quark Effective Theory (HQET) predictions Have previously seen 1-2  discrepancies between lifetime predictions and measurements in B s and  b Expect  (B + ) >  (B 0 )   (B s ) >  (  b ) >>  (B c ) Shorter lifetimes indicate additional (non-SM) decay processes HFAG ,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

7 B s Lifetime Now Agrees with HQET L=1.3 fb -1 displaced vertex trigger ~1100 fully reconstructed B s  D s - (  - )  + ~2000 partially reconstructed B s  D s -  (  0  + ):  0 not reconstructed Sample composition by mass fit  (B s ) =  (stat)  (syst) ps  BsBs KK KK DsDs   HQET prediction with  (B 0 ) ~  (B s ):  (B 0 ) =  ps World best measurement: consistent with theoretical prediction 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

8 B c + Lifetime BcBc  (e)   J/  L=1.0 fb-1 di-muon trigger Shorter lifetime than light B mesons via weak decays of b or c quark or via weak annihilation  Bc =  b (~25%) +  c (~65%) +  W Fit e,  channel separately, then combined  (B c ) = (stat)  (syst) ps Theory:  (B c ) = 0.47  0.59 ps consistent with theoretical prediction 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

9  b Lifetime bb p KK  cc  1.1 fb -1 displaced vertex trigger No helicity suppression  b   c +  - decay Sample composition from mass fit  (  b ) =  (stat)  (syst) ps Theory:  (  b ) =  ps World best measurement: consistent with prediction  b (bud) 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

10 Rare Decays 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

11 B s(d)  e +  -, e + e - Search B s(d)  e  forbidden in SM Possible with R-parity violating SUSY, ED, or Lepto-quarks BR(B  ee) ~ in SM Most of direct searches for LQ set limits in the order of M LQ > GeV/c 2 Pati-Salam model allows for cross-generation couplings 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

12 B s(d)  e , ee Search Results Nbkg = 0.81  0.63 Nbkg = 0.94  0.63Nbkg = 2.66  % C.L. limits: Br(Bs  e  ) 45 TeV/c 2 Br(Bd  e  ) 56 TeV/c 2 95% C.L. limits: Br(Bs  ee) < 3.7  Br(Bd  ee) < 10.6  All limits are world best 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

13 CP Violation 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

14 CP Violation in B s  J/  Decays - CP violation phase  s in SM is predicted to be very small O(λ 2 ) : =0.23 → Any large CP phase is a clear sign of new physics + dominant contribution from top quark - Analogously to the neutral B 0 system, CP violation in B s system occurs through interference of decays with and without mixing: 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary ~ 2

15 Results in Flavor-Tagged B s  J/  1.5  discrepancy with SM at L=1.35 fb -1 Updated results have 1.8  discrepancy with SM  s prediction. Assuming no CP violation (  s =0) mean lifetime:  (B s ) = 1.53 ±0.04 (stat) ±0.01 (syst) ps  = 0.02  0.05 (stat)  0.01 (syst) ps -1 CP-even CP-odd 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

16 CDF and D0 Combined Results D0 result is very similar to CDF’s! (1.7  discrepancy with SM) Updated CDF result is not included. arXiv: G. Hou et al. suggest that discrepancy might due to t’ quark with mass ~300 GeV/c 2 – 1 TeV/c 2 (arXiv: ) t’ search in CDF M(t’) > %C.L. = -2  s 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

17 Prospects Tevatron can search for large value of  s, before LHC starts 6/8 fb -1 expected at the end of 2009/2010 If  s is indeed large, combined CDF and DØ results have good chance to prove it Probability of 5σ observation CDF only 8 fb -1 6 fb -1  s (radians) CDF+DØ (assume twice CDF) current central value 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

18 Summary Prospects CDF has a rich B-Physics program, complementary to B-factories. Recent results (L<2.8 fb -1 ) include : Lifetime measurements Uncertainties are still dominated by statistics.  s measurent 1.8  discrepancy with SM Rare decay B s  e  searches 5 fb -1 on tape and collecting ~50 pb -1 /week New  s results expected this summer Lifetime measurements with more than twice of data New B s  results And much more... Higher precision measurements could give us a stronger hint before the LHC turns on. 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary

19 Backup

20 D0-> mumu World best limit Br(D0  ) < 5.3  95% C.L. 21k 22k < 9.8  10-4 SUSY with R-parity violation SM Prediction:Br(D0  )  4  R-parity violating SUSY allows enhancements up to 3.5  10-6 L = 360 pb-1 Branching ratio relative to D0  +  - No excess observed

21  s Phase and the CKM Matrix - CKM matrix connects mass and weak quark eigenstates - Expand CKM matrix in λ = sin(  Cabibbo ) ≈ To conserve probability CKM matrix must be unitary → Unitary relations can be represented as “unitarity triangles” unitarity relations: unitarity triangles: very small CPV phase  s of order 2 accessible in B s decays ≈ ~1~1 2 ~ =1=1 1,Introduction 2,Production 3, Lifetime 4, Rare decay 5, CP Violation 6, Summary