Measurement of B s Oscillations and CP Violation Results from DØ

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1 Meaurement of B Ocillation and CP Violation Reult from DØ John Ellion Univerity of California, Riveride for the DØ Collaboration PANIC 008, Eilat, Irael 1

2 The DØ Detector Tracker: Excellent coverage η < 3 T olenoid New layer 0 ilicon cloe to beam pipe in 006, improve impact parameter reolution Muon yyem: Coverage and triggering: η < Include toroid magnet Polarity flip of both magnet every two week Reduce detector aymmetrie

3 B Mixing and Ocillation 0 0 Mixing and ocillation convert B B through econd-order weak interaction (box diagram) Ma eigentate: L 0 0 B = p B + q B CP even B = p B q B CP odd H 0 0 Eigentate propagate with different lifetime: τ > τ H L τ 1/ Γ where Γ Γ L +Γ H Probability of mixed and unmixed decay: Δm Γt Vt P( B B; t) = Γe ( 1 coδmt ) Δmd Vtd Γt P( B B; t) = Γ e ( 1+ coδmt ) contrain V td 3

4 Meaurement of Δm Recontruct B decay ignal (S) with low background (B) Flavor at production Oppoite-ide + ame-ide flavor tagging Flavor at decay from muon (or electron or pion) charge Proper decay length: x M 0 B μd M M dt p T cτ = x K, where x cm B = ( pt ) 0 0 μd B K-factor: x M K = p p μd T B T 0 determined from MC = Viible Proper Decay Length (VPDL) Significance: Sig( Δ m ) = SD ε e Δ ( m σ t ) S S + B 4

5 Data Sample and Decay Mode B Decay Mode No. of Signal Event Data (fb 1 ) μ D, D φπ + + ed, D φπ π D, D φπ + *0 μ + D, D K K 0 μ + D, D KK 44,777 ± ,663 ± ± ,098 ± ± π φπ + *0 μ + e φπ K K 5

6 Flavor Tagging and VPDL Determination Same-ide kaon tag and event-charge tag are new addition to the combined flavor tagger Tagging Method ε D Combined SST 1.7 ± 0.6 % Comb. OST w/o event charge.5 ± 0. % Event charge OST 1.5 ± 0.5 % All 4.5 ± 0.9 % Intallation of Silicon Layer 0 in 006 Improved VPDL reolution and election efficiency for Run IIb data (~ 1. fb 1 ) 6

7 Combined amplitude can nomix,mix Prob ( x) K cτ B Combined Reult = Kx exp( )(1 ± DAco( ΔmKx/ c)) cτ B Δm obtained from Combined likelihood can DØ reult: Δ m = ± ± V V td t (tat.) 0.30 (yt.) p with.9 σ ignificance = ± (exp.) (theor.) HFAG combination: t V V td = ± (exp.) (theor.) DØ Run II Preliminary 7

8 B J/ψ φ: CPV via B Mixing B B 0 0 Ma eigentate: 0 0 BL = p B + q B CP even B = p B q B CP odd 0 0 H CPV: q/p 1, or interference between direct/mixed decay CPV phae very mall in SM, ~ 0.04 [A. Lenz and U. Nierte, JHEP 0706, 07, (007), arxiv:hep-ph/061167] New Phyic could eaily enhance CPV phae Look for non-zero phae a indicator of new phyic: NP φ φ VV = = arg 0.04 * SM t tb β * VV c cb 8

9 Analyi I: Auming no CPV 0 0 *0 Compare B and Bd J / ψ K J / ψφ Meaure linear polarization amplitude and lifetime Tet flavor SU(3) ymmetry, factorization, and obtain lifetime ratio B d B d B B 9

10 Decay amplitude Strong phae B d J/ψ K *, B J/ψ φreult New reult for PANIC08 Parameter A 0 A δ 1 (rad) δ (rad) δ (rad) τ (p) 1 ΔΓ (p ) 0 B d ± 0.011(tat) ± 0.013(yt) ± 0.07(tat) ± 0.006(yt) 0.30 ± 0.013(tat) ± 0.05(yt) 0.44 ± 0.03(tat) ± 0.014(yt) 0.38 ± 0.06(tat) ± 0.09(yt) 3.1 ± 0.06(tat) ± 0.06(yt) ± 0.018(tat) ± 0.034(yt) ± 0.060(tat) ± 0.08(yt) (tat) ± 0.001(yt) 0 B.7 (tat) 0.6(yt) ± B d reult competitive and conitent with CDF/BaBar/Belle Meaurement of the trong phae indicate preence of 0 *0 final-tate interaction for Bd J / ψ K δ 1 i 3.5σ away from 0 Comparion of amplitude and trong phae how no evidence for violation of SU(3) flavor ymmetry δ = δ for B δ1 = 3.59 ± 0.06(tat) ± 0.09(yt) d arxiv: Submitted to PRL 10

11 1967 ± 65 B decay Analyi II: CPV in B J/ψ φ CP-even CP-odd CP-even CP-odd Ue a maximum likelihood fit to ma, lifetime, 3 decay angle Allow eparation of CP-even and CP-odd component coθ ΔM contrained to meaured value (CDF) and trong phae contrained to value meaured for B d at B-factorie, allowing ome degree of violation of SU(3) ymmetry B flavor at production determined uing oppoite-ide + ame-ide tagging 11

12 CP Violation in B J/ψ φ: Reult (trong phae contrained) Reult: τ = ± ± 0 ( B ) (tat) 0.01(yt) p (tat) 0.01 (yt) p ΔΓ = ± ± φ = 0.57 (tat) (yt) CP-violating phae Probability of SM = 6.6% ~1.8σ arxiv: PRL, in pre 1

13 DØ + CDF Combined Reult Combination of reult, without contraint on trong phae With contraint from: DØ + CDF Flavor-pecific B lifetime B emileptonic charge aymmetry φ =.36 rad, 0.77 rad ΔΓ = p, p 90% C.L. 1-d region: φ [.85, 1.65], [ 1.47, 0.9] ΔΓ [ 0.64, 0.036], [0.036, 0.64] DØ + CDF + contraint 13

14 CPV and Br(B D (*) D (*)) B D D The decay i predominantly CP even and i related to ΔΓ Γ Γ : CP even odd 0 (*) (*) CP 0 (*) (*) ΔΓ CP Br[ B D D ] [ 1 + O( ΔΓ / Γ) ]; ΔΓ =ΔΓ coφ Γ + + Look for event in which D φ π and D φ μν Extract ignal from d likelihood fit to data in m(d φπ) m(φμ) plane Reult: Br B D D 0 (*) (*) [ ] = 0.04 ± (tat.) ± (yt.) CP ΔΓ = ± (tat.) ± (yt.) Γ New Reult DØ Run II Preliminary Conitent with SM (0.17 ± ) 14 1 A. Lenz and U. Nierte, JHEP 0706, 07, (007)

15 Direct CP Violation in B ± J/ψ K ± (π ± ) Search for direct (i.e. not via mixing) CP violation ± ± ± ± Meaure charge aymmetry in B J / ψ K and B J / ψ π Charge aymmetry defined by A ( B J / ψ K ( π )) = CP N( B J / ψ K ( π )) N( B J / ψ K ( π )) N( B J / ψ K ( π )) + N( B J / ψ K ( π )) CP violation non-zero A CP In SM, A B J K J 1 CP ( + / ψ + ) 0.003, ~ 0.01 for / ψπ + Due to interference of tree-level and penguin decay diagram New phyic may ignificantly enhance A CP 1 W.-S. Hou, M. Nagahima, A. Soddu, arxiv:hep-ph/ I. Dunietz, Phy. Lett. B 316, 561 (1993); W.-S. Hou, arxiv:hep-ph/ (1999). 15

16 J/ψ K ± (π ± ) Ma Ditribution Fit to um of contribution from B J / ψ K, B J / ψπ, and * B J / ψ K, a well a combinatorial background (BKG) From fit we find ~40k B J / ψ K event ~1.6k B J / ψ π event Aymmetry meaurement method account for poible production/detector aymmetrie Reult: + + A ( B J / ψ K ) = ± (tat.) ± (yt.) CP + + A ( B J / ψπ ) = 0.09 ± 0.08 (tat.) ± 0.03 (yt.) CP Conitent with world average Factor of.5 improvement in preciion for ( + / + ACP B J ψ K ) Competitive preciion for ( + / + A ) CP B J ψ π PRL 100, 1180 (008) 16

17 CP Violation in Semileptonic B Decay μ ν φπ φ New earch for CP Violation in B D X,( D, K K ) by meaurement of the charge aymmetry uing a timedependent analyi with flavor tagging Technique imilar to B ocillation analyi, modified to include CPV and tudy of detector aymmetrie DØ Run II Preliminary μ + D D μ + : ± 718 event Signal region 1.91 < M(D ) <.0 GeV/c Reult: a l = ± (tat.) (yt.) New Reult DØ Run II Preliminary Mot precie direct meaurement to date 17

18 Summary and Outlook Our reult are contributing to ignificant advance in undertanding of the B ector and CP violation Powerful probe of new phyic Poible hint of new phyic in B J/ψ φanalyi i tantalizing need more data The Tevatron i running well and propect look good Fermilab i planning to run through FY010 Already have 4.5 fb 1 on tape and expect up to ~7 fb 1 by end of run Factor of ~.5 more tatitic than reult hown here Improvement in analye and combination with CDF will yield big gain 18