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

Tevatron Only machine currently at both the Energy and Luminosity Frontiers Complementary to other machines at each frontier –Large B s data set compared to B factories –Different channels compared to LHC qqbar  WH  l bb vrs gg  H  Weak sector (charginos, neutralinos) vrs strong sector (squarks, gluinos) Interference effects (top A fb ) vrs resonance search (G A ) Will be superseded by LHC and super B factories but expect to be relevant for a few more years –Still have a lot to analyze with the 2011 data. 2/28 1/11/11 B. Casey, SEL11 pbar complex Now producing 2.6 ng of antimatter per year

1/11/11 3/28 B. Casey, SEL11 Some familiar faces (plus many more)

Overlapping beauty 1/11/11 4/28 B. Casey, SEL11 B  VV polarization CPV in charm mixing B  D ADS K

Complementary Beauty 1/11/11 5/28 B. Casey, SEL11 Very Rare Processes charged currents neutral currents B factories Tevatron Anomalous CP Violation  b =  s = 1  b =  s = 2 b u b s ll l+l+ ll b s s b b s q q

6 Leptonic B decays Standard Model rate well understood Standard Model rate is small New physics enhancements can be large SM BF: B(B s →  ) = (3.6±0.3) x Buras, arXiv: B. Casey, SEL11 1/11/11 6/28

K p b c K BsBs   Signal and Background c p p b b   p p BsBs   b p p   b c Signal sequential double B→KK B. Casey, SEL11 1/11/11 7/28

Background reduction SV PV Flight length significance sidebands Signal MC + J/  K data and MC Minimum DCA Signal MC + J/  K data and MC sidebands Signal MC + J/  K data and MC Angle between momentum and direction Vertex  2 sidebands Signal MC + J/  K data and MC p T (  ) sidebands Signal MC + J/  K data and MC sidebands Minimum p T (  ) Signal MC + J/  K data and MC   B. Casey, SEL11 1/11/11 8/28

Background reduction Multivariate discriminants Expect ~3 signal events in D0 data with these cuts B. Casey, SEL11 1/11/11 9/28 Expect ~1 signal event in CDF data with these cuts Almost 2x rapidity coverage at D0 + higher purity

Results preliminary 2009: 43 x observed (12xSM) 33 x expected (9xSM) B. Casey, SEL11 1/11/ : 51 x observed (14xSM) 38 x expected (11xSM)

Why? 1/11/11 11/28 B. Casey, SEL11 Tracker radius 1.3 m vrs 0.5 m

What’s next? 1/11/11 12/28 B. Casey, SEL11 ~20k B 3.7 fb -1, 2 TeV vrs ~10k B 34 pb -1, 7 TeV A. Schopper, CERN Council Report, Dec

CPV in B s mixing 1/11/11 13/28 B. Casey, SEL11 (WS Hou)

Dimuon charge asymmetry 1/11/11 14/28 B. Casey, SEL11 t W W b s b s t W W b s b s t t B s mixing in the mirror

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 -1 RunII 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 1/11/11 15/28 B. Casey, SEL11 Iron toroid + -

Measurement history at Dzero 1 fb-1 result: –A SL = -(0.92 ± 0.44 ± 0.32)% –World leading measurement –Dominant error is now Kaon asymmetry determined using D*  D , D  K , K  X Raw asymmetry A = -(0.05± 0.13)% Kaon asymmetry A K = -(0.23 ± 0.08)% 1/11/11 16/28 B. Casey, SEL11

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 1/11/11 17/28 B. Casey, SEL11

Dimuon results A SL = (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: ± /11/11 18/28 B. Casey, SEL11

19 B s →J/   : Kaon type CPV Pseudo scalar →Vector + Vector. Both even and odd states contribute. Angular analysis tells if its even or odd. Lifetime measurement tells if its long or short Look for even states decaying with a longer lifetime ⇛ CPV  ≈ 10%  Short   Long  B s (even) B s (odd)

20 B s →J/   : B d type CPV Need to analyze B s and B s initial states separately BsBs BsBs J/  Mirror image of a double slit experiment   K K Fragmentation: s or s? recoil: b or b?  K Validate tagging performance using B ± samples Actual performance expected performance BsBs BsBs J/  p p

21 J/   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 2  effect

Future 1/11/11 22/28 B. Casey, SEL11 A. Schopper, CERN Council Report, Dec

23 Future The large anomalous CPV in B s 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  QCD Need different leptons to determine if the new phase is universal New g-2 experiment: muon EDM below 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 Large B s CPV shrinks available parameter space Titanium neutron Mercury Buras, Isidori, Paradisi arXiv: B s CPV

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. 1/11/11 24/28 B. Casey, SEL11