Experiments on CP Violation in B Meson decay David Hitlin Matter and Antimatter: Fact and Fancy April 16, 2010 David Hitlin Quinn Symposium April 16, 2010 1 The CP problem(s) CP violation in the strong interactions is weak, while CP violation in the weak interactions is strong Helen Quinn has played a role in both these problems She has been a member of the BABAR Collaboration since (before) its inception Her insight has been brought to bear on a variety of important problems concerning CP violation measurements, which I will refer to as we proceed She also was co-editor of the BABAR Physics Book, and co-author of a mystery thriller David Hitlin Quinn Symposium April 16, 2010 2 The CKM Matrix In 1973 Kobayashi and Maskawa realized that extending Cabibbo’s two generation mixing matrix that relates the quark mass eigenstates to the weak eigenstates to a third generation introduced a phase that could account for CP-violating 0 effects first seen in K L decay in 1964 “Hadronic engineering” issues did not allow a quantitative comparison of the phase in theory and experiment Bigi and Sanda proposed that CP –violating asymmetries in B0 decays to CP eigenstates could be directly related to theoretical quantities In 2001 BABAR and Belle measured the CP asymmetry in b® ccs decays, showing that the CKM phase could account for the observation and leading to the award of the 2008 Nobel Prize to Kobayashi and Maskawa David Hitlin Quinn Symposium Vud Vus Vub V Vcd Vcs Vcb V V V ts tb td d ' d s' V s b' b April 16, 2010 3 The elevator speech (if the elevator is in the physics department) The Wolfenstein parametrization The Unitarity condition (1 of 6) VCKM VudVub* VcdVcb* VtdVtb* 0 1 2 / 2 A 3 ( i ) 4 1 2 / 2 A 2 O ( ) A 3 (1 i ) A 2 1 The “b” Unitarity Triangle The UT phases VtdVtb* VcdVcb* arg arg * * VudVub VtdVtb NB : g VudVub* VtsVtb* g arg s arg * * V V V V cd cb cs cb CP-violating asymmetries in Bd, Bs decays can measure all the phases Combinations of tree level decay BRs can measure g Since any combination of three sides or angles determines a triangle, we can perform a unique set of overconstrained tests of the consistency of the CKM matrix David Hitlin Quinn Symposium April 16, 2010 4 At the start of the “B Factory era” Dib, Dunietz, Gilman and Nir - 1989 The mass of the top quark, required to sharpen UT tests, was unknown David Hitlin Quinn Symposium April 16, 2010 5 David Hitlin Quinn Symposium April 16, 2010 6 At the start of the “B Factory era” David Hitlin Quinn Symposium Dib, Dunietz, Gilman and Nir - 1989 April 16, 2010 7 Many measurements provide unitarity triangle constraints Theoretical errors are often pertinent David Hitlin Quinn Symposium April 16, 2010 8 To measure the CP asymmetry in decays to CP eigenstates requires a time-dependent analysis ( B fCP ) ( B fCP ) ACP (t ) 0 0 ( B fCP ) ( B fCP ) 0 0 CP [ S sin m t C cos m t ] David Hitlin 2 Im CP S 2 1 | CP | 1 | CP | 2 C 1 | CP | 2 Quinn Symposium CP e i 2 April 16, 2010 A( B 0 fCP ) A( B 0 fCP ) 9 Here’s how: J /y 0 Brec U (4S ) e - e K + 0 S Reconstruct exclusive B decays to CP eigenstates and flavor eigenstates and tag the flavor of the other B decay Select BCP candidates 0 Btag z K ( B 0 J / K S0 , etc.) Select Btag events using, primarily, and Bflav candidates leptons and K's from B hadronic decays & determine B flavor (B 0 D*- p + , etc.) Measure the mistag fractions wi and determine the dilutions Di = 1- 2 wi Measure z between BCP and Btag to determine the signed time difference t between the decays Determine the resolution function for z i 3 fi R (t ; aˆ ) exp (t i ) 2 / 2 i2 i 1 2 i David Hitlin Quinn Symposium April 16, 2010 10 Global CKM Fit Consistency of angles 89.0 4.4 o 4.2 21.1 0.9 o g 75 12 o g 185 13 o Consistency of angles and sides from global fit Overall good fit (CKMFitter: global p-value 45%) ~2σ tension between sin2β and εK / Vub correction to εK will make fit UTFit: 0.154 0.022 CKMFitter: 0.1390.025 0.027 0.342 0.014 0.3410.016 0.015 David Hitlin Quinn Symposium worse Buras, Guadagnoli, PRD78, 033005 (2008) April 16, 2010 11 sin2β from b ccs decays c J / c s 0 d KS b B 0 d V*td b d 0 s KS c J / c t B0 d V*td t * * V V V V qA 2i tb td cb cs tree (1)e * * pA VtbVtd VcbVcs David Hitlin Quinn Symposium April 16, 2010 12 sin2β from b ccs decays Theoretically clean measurement of |S| = sin2β with B J/ψ K0, J/ ψ K*, ψ(2SKS, cKS, & cc1KS by BABAR and Belle SWA 0.672 0.023 CWA 0.004 0.019 BABAR, PRD 79,072009 (2009) S 0.687 0.028 0.012 C 0.024 0.020 0.016 David Hitlin (21.1 0.9) Quinn Symposium statistically limited April 16, 2010 13 David Hitlin Quinn Symposium April 16, 2010 14 David Hitlin Quinn Symposium April 16, 2010 15 sin2 from b uud decays Vub b B d 0 d u u d V*td b B d 0 t V*tdt d u u d ei 2 ei 2g e2i mixing decay David Hitlin Quinn Symposium April 16, 2010 16 sin2 from B0 Two amplitudes (P/T ~ 0.3) : b → u “tree” b → d “penguin” d g e i 2 e i 2g e2i PRL 98, 211801 (2007) mixing decay Sππ sin2aeff = sin2( ) S 0.61 0.10 0.04 (5.3 ) C 0.55 0.08 0.05 (5.5 ) S ,WA 0.65 0.07 C ,WA 0.38 0.06 Excluded at 95% CL Determine from isospin analysis Gronau & London, PRL 65, 3381 (1990) David Hitlin Quinn Symposium April 16, 2010 17 Ouch ! Gronau-London-Sinha2 Grossman-Quinn David Hitlin Quinn Symposium April 16, 2010 18 sin2 from B , , VV decay B Separate isospin analysis for each polarization amplitude Longitudinal polarization >90% Small penguin contribution in B → 0 0 , 0 Br B 0 (24.2 3.2) 106 0 6 Br B (24.0 2.0) 10 0 0 0 6 Br B (0.73 0.28) 10 S 0.05 0.17 C 0.06 0.13 PRL 102, 141802 (2009) =89.0 David Hitlin +4.4 4.2 Quinn Symposium April 16, 2010 19 g from B (*) D K Decays Rates of B± D (*) K± decays are sensitive to g through interference of b c and b u transitions (*)0 ( *)0 Need states accessible to D and D Several neutral D (*) final states have been studied by BABAR, Belle and CDF Must also determine A(b u ) rb s B b Vcb u b B u u c u Vub K D0 u 0 c D s K u A(b c) D decays: GLW : CP eigenstates , KK, etc.) 3.4 σ Gronau & London, PLB 253, 483 (1991); Gronau & Wyler, PLB 265, 172 (1991) ADS: Flavor DCSD states (K) Atwood, Dunietz, & Soni, PRL 78, 3257 (1997), Atwood, Dunietz, & Soni, PRD 63, 036005 (2001) GGSZ: 3-body decays (KS, KSKK) Giri, Grossman, Soffer, & Zupan, PRD 68, 054018 (2003) Bondar, PRD 70, 072003 (2004) New BABAR measurement with first evidence for ADS signal in B- → DK- David Hitlin Quinn Symposium Lopez-March @ EPS’09 April 16, 2010 20 g from B- (*) D K Interference in B Decays decays with 3-body Dalitz analysis of D KSπ π, D KSKK are sensitive to g - David Hitlin (*) D K Quinn Symposium April 16, 2010 21 CKM Fitter results as of Moriond 2010 Adding in the CP asymmetry measurements from BABAR and Belle, we now have a set of highly overconstrained tests, which grosso modo, are well-satisfied UTFit: 0.154 0.022 0.342 0.014 David Hitlin 89.0 CKMFitter: 0.139 0.025 0.027 0.3410.016 0.015 Quinn Symposium 4.4 o 4.2 21.1 0.9 o g 75 12 o g 185 13 April 16, 2010 22 o A decade of progress David Hitlin Quinn Symposium April 16, 2010 23 sufficient constraints to explore subsets All Angles only David Hitlin CP-violating Tree amplitudes Quinn Symposium CP-conserving Loop amplitudes April 16, 2010 24 Whither Heavy Flavor Physics ? Flavor physics provides the experimental foundation of much of the Standard Model Heavy flavor physics plays an important role, in that it furnishes many parameters that can be determined experimentally with precision compared with reliable theoretical predictions As such, heavy flavor physics has served to establish major pillars of the Standard Model: the particle content the weak couplings the suppression of flavor-changing neutral currents, …… and to constrain what lies beyond the Standard Model When new physics is found at the LHC Flavor physics has provided, and will continue to provide, unique information on the nature of any new physics found at LHC David Hitlin Quinn Symposium April 16, 2010 25 Can we learn more ? Unitarity triangle tests These primarily involve measurements in the B system, but require measurements of the Cabibbo angle, eK and theoretical inputs 1. Does the agreement of the overconstrained tests stand up to detailed scrutiny ? 2. Can the UT tests be improved with better theoretical calculations and/or improved experiments ? 3. Is there any room for new physics ? There are a few issues Overconstrained tests of three generation unitarity Does the unitarity triangle close ? Are there extra mixing phases ? Are there extra CP-violating phases ? David Hitlin Quinn Symposium April 16, 2010 26 David Hitlin Quinn Symposium April 16, 2010 27 The B(B→tn) conflict 2 2 2 2 G f m m m F t B B ( B t n t ) 1 2t 8 mB Vub 2 Also constrains Higgs doublet models G. Eigen David Hitlin Quinn Symposium April 16, 2010 28 The K problem The four B→K decays provide four branching fraction measurements, four direct CP asymmetries and one mixing-induced CP asymmetry (B0→K0 0) The decay amplitudes are related by isospin A( B 0 K ) 2 A( B K 0 ) 2 A( B 0 K 0 0 ) A( B K 0 ) 0 The amplitudes can be written in terms of tree and penguin Standard Model amplitudes A SM sum rule (Gronau-Rosner) relates the asymmetries 0 0 0 0 B ( K ) t 2 B ( K ) t 2 B ( K ) 0 0 0 0 A( K ) A( K ) A( K ) A( K ) B ( K )t 0 B ( K )t 0 B ( K ) Consistent with the SM at the 20% level New Physics: 1 2 if C if PNP e P A e 3 C ,u C ifEW C EW , NP P e u C ,u ifuC 3 C , d ifdC A e C , d if CdC A e A e NP in PNPeifp A(K00) = -0.15 NP in PCEW,NPeifEW A(K00) = -0.03 ACP A( K ) A( K 0 ) David Hitlin Quinn Symposium April 16, 2010 G. Eigen 29 βs from Bs → J/ψf decays SM predicts very small βs (~0.02) Thus sensitive to new physics in Bs mixing DØ and CDF measure βs with fit to decay time and angular distribution of Bs → J/ψf Simultaneous fit to extract ΔΓs and βs DØ and CDF working on updates with >2x samples LHCb sensitivity with 0.5 fb-1: s 0.02 David Hitlin Quinn Symposium April 16, 2010 30 Does the agreement of the overconstrained tests stand up to detailed scrutiny ? There is actually some tension, Lunghi and Soni and there are enough constraints to explore these issues Caveats: There may be Standard Model explanations for some effects All issues are at the <3 level Inclusive and exclusive Vub determinations are not in good agreement There are also issues with inclusive/exclusive Vcb The B(B→tn) conflict in Vub The Bs → ψϕ phase The K problem The agreement of the fitted, i.e., SM-predicted, value of sin 2 vs the directly measured value using tree decays and loop decays is not perfect David Hitlin Quinn Symposium April 16, 2010 31 Is there a fourth quark generation ? A fourth generation CKM-like mixing matrix has 2 additional quark masses 3 additional mixing angles 2 additional CP-violating phases A recent analysis by Bobrowski, Lenz, Reidl and Rohrwild (Phys.Rev.D79:113006,2009) shows that large regions of the new parameter spaces are still allowed SuperB will be the primary tool to close down, or, perhaps find, non-zero values of these fourth generation parameters q24 14 q14 13 Potential motivation (Hou): with 4 generations and mt', mb' ~300-600 GeV, gain 1013-1015 in the effect of SM CP violation on the baryon asymmetry of the universe ! David Hitlin Quinn Symposium April 16, 2010 32 Correlations in CP asymmetries in rare decays are diagnostic of SM4 models SM4 models have been comprehensively explored by Buras, Duling, Feldmann, Heidsieck, Promberger & Recksiegel (arXiv:1002.2126v2 [hep-ph]) Many CKM extension patterns are possible in the mixing matrix For example, a 1, , 2, 3, 4 pattern for 0ff-diagonal terms leads to a “Wolfenstein” parametrization: = Many other VSM4 patterns are There are also additional effects in KL, Bd and Bs decays David Hitlin (%) possible. They can be identified, and distinguished from SUSY and extra dimension models, by the observed patterns of CP-violating effects: Quinn Symposium April 16, 2010 33 Okada, et al: a sample of new physics models David Hitlin Quinn Symposium April 16, 2010 34 CPV Probes of New Physics In the Standard Model we expect the same value for “sin2 ” in b ccs, b ccd , b sss, b dds modes, but different SUSY models can produce different asymmetries Since the penguin modes have branching fractions one or two orders of magnitude less than tree modes, a great deal of luminosity is required to make these measurements to meaningful precision B 0 J / K S0 B 0 f K S0 q A Vtb*Vtd VtbVts* 2i penguin ( 1) e * * p A VtbVtd VtbVts Vtb*Vtd VcbVcs* qA 2i tree ( 1) e pA VtbVtd* Vcb*Vcs W- b u,c,t c- H- s b u,c,t e i (2 f SUSY ) David Hitlin s b ~ ~~ u,c,t 0 g, ~c s b ~ ~~ d,s,b s A Sf K sin(2 f SUSY ) A Quinn Symposium April 16, 2010 35 from b s(qq) penguin loop decays b B 0 t BABAR PRD 79, 052003 (2009) B 0 ' K S0 s 467M BB g In the SM the penguin decay B 0 ' K S0 amplitude is dominant and has same weak phase as bqqs amplitude expect to measure |S| = sin(2) SM contributions from suppressed diagrams expected to be small (sin(2) = sin(2eff) sin(2) ~ 0.01-0.1) Penguin decays with b → sqq loop sensitive to New Physics from heavy particles New Physics contributions could cause large sin(2) David Hitlin Quinn Symposium N B0 N B 0 N B0 N B 0 sin 2 eff 0.57 ± 0.08 ± 0.02 C 0.08 ± 0.06 ± 0.02 April 16, 2010 36 sin2β from b s(qq) penguin loop decays CP asymmetries have been measured in 9 different b s (qq) modes by BABAR/Belle All measurements of sin2βeff are Theoretically clean modes consistent with sin2βb→ccs C is consistent with zero Naïve average sin2βeff of all b → sqq modes used to be ~3σ lower than sin2β (~2004), now ~1σ Some modes (fK0, 'K0, K0K0K0) have relatively small theoretical uncertainties (~5%) sin2eff ,clean 0.59 0.06 David Hitlin Quinn Symposium April 16, 2010 37 Gold 1) b sss decays have 1-5% the rate of b ccs decays 2) There are important penguin and tree corrections b VtbVts* ~ 2 W t g Silver d b VtbVts* ~ 2 W t g d s s s d Bronze d f K 0 f s s s VtbVts* ~ 2 W t s d g d d K0 b ', f0 d W K0 u u s d ', f0 K 0 29 VubVus* ~ 4Ru e ig b K0 , , 0 0 d W u u s d 0 , 0 , K 0 J / y K S0 David Hitlin 4 VubVus* ~ 4Ru e ig d b VubVus* ~ 4Ru e ig W u s b s g d s d Quinn Symposium April 16, 2010 20 Corrections of up to 20% corrections for sin2β are possible These corrections can be calculated and/or bounded 440 x10-6 38 Can we resolve these outstanding issues in heavy flavor physics? To access the very rare b, c and t decays that can show effects due to a fourth generation, SUSY, extra dimensions, etc., requires large hadronic data samples (viz. LHC) and an e+e- data sample ~100x as large as the total BABAR/Belle data set (~1.3 ab-1) As none of us is getting any younger, obtaining this sample in our lifetime requires an asymmetric collider with a luminosity of 1036, which can record 15 ab-1/New Snowmass Year, as well as a detector that can cope with the event rates and backgrounds BABAR SuperB David Hitlin Quinn Symposium April 16, 2010 39 Lepton Flavor Violation in t decays Super B Factory sensitivity directly confronts New Physics models SuperB sensitivity For 75 ab-1 We expect to see LFV events, not just improve limits David Hitlin Quinn Symposium April 16, 2010 40 Polarized t’s can probe the chiral structure of LFV in a model-independent manner t tt A longitudinally polarized electron beam, producing polarized t’s, can determinate the chiral structure of lepton flavor-violating interactions Dassinger, Feldmann, Mannel, and Turczyk JHEP 0710:039,2007; [See also Matsuzaki and Sanda Phys.Rev.D77:073003,2008 ] Also: • Reduction in backgrounds for rare t decays • Measurement of t anamolous magnetic moment • Search for CP or T violation in t production and decay David Hitlin Quinn Symposium April 16, 2010 41 Polarized t’s can probe the chiral structure of LFV in a model-independent manner t tt A longitudinally polarized electron beam, producing polarized t’s, can determinate the chiral structure of lepton flavor-violating interactions Dassinger, Feldmann, Mannel, and Turczyk JHEP 0710:039,2007; [See also Matsuzaki and Sanda Phys.Rev.D77:073003,2008 ] Also: • Reduction in backgrounds for rare t decays • Measurement of t anamolous magnetic moment • Search for CP or T violation in t production and decay David Hitlin Quinn Symposium April 16, 2010 42 A DNA Chip for New Physics Altmannshofer, Buras, Gori, Paradis and Straub Nucl.Phys.B830, 7-94, 2010 David Hitlin Quinn Symposium April 16, 2010 43 The National Research Plan for 2010-2012 of the Italian Ministry of Education and Science David Hitlin Quinn Symposium April 16, 2010 44 Conclusions CP violation experiments have provided some of the key building blocks for the construction of the three generation Standard Model Through a series of overconstrained tests the B factories have convincingly shown that the CKM phase can account for a wide variety of experimental phenomena, although there are still some intriguing discrepancies This, of course, leaves us with the mystery of the origin of the matter-antimatter asymmetry (leptogenesis ?) There is still room for a fourth generation, which could be pertinent to the baryon symmetry problem SM extensions provide many additional CP-violating phases Super B Factories, now hopefully near to becoming a reality, can provide unique sensitivity to explore this area, and, more generally, the flavor structure of any new physics found at the LHC David Hitlin Quinn Symposium April 16, 2010 45