Beauty at the Tevatron

1. Beauty at the Tevatron Brendan Casey SEL11, TIFR, 1/11/11

2. Tevatron • Only machine currently at both the Energy and Luminosity Frontiers • Complementary to other machines at each frontier • Large Bs data set compared to B factories • Different channels compared to LHC • qqbar  WH  lnbbvrsgg H gg • Weak sector (charginos, neutralinos) vrs strong sector (squarks, gluinos) • Interference effects (top Afb) vrs resonance search (GA) • Will be superseded by LHC and super B factories but expect to be relevant for a few more years • Still have a lot to analyze with the 2011 data. pbar complex Now producing 2.6 ng of antimatter per year B. Casey, SEL11

3. Some familiar faces (plus many more) B. Casey, SEL11

4. Overlapping beauty BDADSK BVV polarization CPV in charm mixing B. Casey, SEL11

5. Complementary Beauty Very Rare Processes neutral currents charged currents b b l- l- u s n l+ B factories Tevatron Anomalous CP Violation Db = Ds = 1 Db = Ds = 2 s b q b s b s q B. Casey, SEL11

6. Leptonic B decays • Standard Model rate well understood • Standard Model rate is small • New physics enhancements can be large SM BF: B(Bs→mm) = (3.6±0.3) x 10-9 Buras, arXiv:0904.4917 B. Casey, SEL11 6/28

7. Signal and Background m m c m b Bs m p p m m c b b b p p p p c K b Bs p K m m sequential Signal double B→KK B. Casey, SEL11

8. Background reduction pT (mm) MinimumpT (m) Minimum DCA Angle between momentum and direction Vertexc2 sidebands sidebands Signal MC + J/y K data and MC Signal MC + J/y K data and MC Signal MC + J/y K data and MC Signal MC + J/y K data and MC Flight length significance Signal MC + J/y K data and MC Signal MC + J/y K data and MC sidebands sidebands sidebands sidebands m m SV PV B. Casey, SEL11

9. Background reduction Multivariate discriminants Expect ~1signal event in CDF data with these cuts Expect ~3 signal events in D0 data with these cuts Almost 2x rapidity coverage at D0 + higher purity B. Casey, SEL11

10. Results 2010: 51x 10-9observed (14xSM) 38 x 10-9expected (11xSM) preliminary 2009: 43 x 10-9observed (12xSM) 33 x 10-9expected (9xSM) B. Casey, SEL11

11. Why? Tracker radius 1.3 m vrs 0.5 m B. Casey, SEL11

12. What’s next? ~20k B+ @ 3.7 fb-1, 2 TeV vrs ~10k B+ @ 34 pb-1, 7 TeV A. Schopper, CERN Council Report, Dec. 17 2010 B. Casey, SEL11

13. CPV in Bs mixing (WS Hou) B. Casey, SEL11

14. Dimuon charge asymmetry Bs mixing in the mirror s b t W W s b t s b t W W s b t B. Casey, SEL11

15. Measurement history at Dzero • 1992: first internal note outlining measurement • 1994: 7.3 pb-1: A = (81-96)/(81+96) • 1996: significant asymmetries observed due to asymmetries in range-out. • From then on, Dzero switches polarity every few weeks to enable this measurement • 2003: analysis of ~100 pb-1RunII data indicates we are competitive. Begin planning for a 1 fb-1 result. • Dimuon result. Single muon result ruled out because completely dominated by Kaon asymmetry Iron toroid + - B. Casey, SEL11

16. Measurement history at Dzero • 1 fb-1 result: • ASL = -(0.92 ± 0.44 ± 0.32)% • World leading measurement • Dominant error is now Kaon asymmetry determined using D*Dp, DKp, KmX • Raw asymmetry A = -(0.05± 0.13)% • Kaon asymmetry AK = -(0.23 ± 0.08)% B. Casey, SEL11

17. 2010 Update • Need a way to constrain the Kaon asymmetry • Two samples: • Like-sign dimuon system = physics + Kaon • Single muon system: asymmetry is almost entirely from the Kaons • Use the single muon system to make a high statistics measurement of the kaon asymmetry and subtract it from the dimuon asymmetry B. Casey, SEL11

18. Dimuon results • ASL = (0.957±0.251±0.146)% • Systematic error dominated by Kaon asymmetry • In dimuon analysis: • 2.1% • In combined single and dimuon analysis: • 0.15% • Verified the B content by measuring the mixing probability in the first fb-1 data set • X = 0.136±0.001±0.024 • PDG: 0.1281± 0.0076 B. Casey, SEL11

19. Bs→J/yf: Kaon type CPV Pseudo scalar →Vector + Vector. Both even and odd states contribute. Bs(even) Bs(odd) t(Short) t(Long) Angular analysis tells if its even or odd. Lifetime measurement tells if its long or short Dt/t ≈ 10% Look for even states decaying with a longer lifetime⇛ CPV

20. Bs→J/yf: Bd type CPV Validate tagging performance using B± samples Mirror image of a double slit experiment Bs J/y f Bs Bs J/y f Bs m Need to analyze Bs and Bs initial states separately m Actual performance K K K p Fragmentation: s or s? m p recoil: b or b? expected performance

21. J/yf results Results taken from a multi-parameter fit including flavor, lifetime, polarization, backgrounds, CP conserving, and CP violating interference Latest comb not available but expect less than 2s effect

22. Future A. Schopper, CERN Council Report, Dec. 17 2010 B. Casey, SEL11

23. Future Large Bs CPV shrinks available parameter space • The large anomalous CPV in Bs mixing reported at the Tevatron + minimal flavor violation predicts EDMs are “around the corner!” • Gino Isidori, ICHEP 2010 plenary talk • Need lepton and quark EDM searches to distinguish new weak interaction from a small QQCD • Need different leptons to determine if the new phase is universal • New g-2 experiment: muon EDM below 10-21 e-cm • Nuclear EDMs can be probed at Project X wit copious production of high-Z nuclei to perform EDM measurements far beyond limits from Hg 10-25 Titanium 10-30 neutron Mercury Bs CPV Buras, Isidori, Paradisi arXiv:1007.5291

24. Conclusions • Beauty at the Tevatron has been beautiful (even in a somewhat ugly environment.) • Next round of updates should still be interesting and competitive. Then its LHCb’s turn. • In any case, the Tevatron has clearly demonstrated the advantages of having a luminosity frontier program at an energy frontier machine. B. Casey, SEL11