David Brown Lawrence Berkeley National Lab BaBar Collaboration CKM phase and CP Violation in B Decays August 14, 2007 Daegu, Korea

D. Brown, CKM phase and CP Violation in B Decays2 Talk Outline l Review of CPV in the B system Results on the CKM unitarity angle  =  1 Results on the CKM unitarity angle  =  2 Results on the CKM unitarity angle  =  3 Results on the B s phase angle  s l Results on Direct CPV l Conclusions I will concentrate on (some) New Results

D. Brown, CKM phase and CP Violation in B Decays3 Quark-Sector Flavor in the SM l 3 known generations of quark doublets l (u,d) (c,s) (t,b), EM charge (2/3, -1/3) l Origin of families unknown in SM l Only the charged-current EW interaction can change flavor in the SM l EW eigenstates aren’t mass eigenstates l Only SM connection between generations!  V CKM

D. Brown, CKM phase and CP Violation in B Decays4 The CKM matrix l Relates EW flavor and quark mass eigenstates l No prediction of values within SM l 3 generations, Unitarity  3 rotations, 1 phase l Non-zero phase implies CPV in flavor transitions l New Physics (NP) with non-SM flavor couplings would make the CKM description incomplete l Eg: 4th generation, SUSY, … V ud V us V ub V cd V cs V cb V td V ts V tb A 3 (  - i  ) /2 A 2 A 3 ( 1 -  - i  ) - A 2 1 = + O( 4 ) V CKM = Wolfenstein parameterization ≈ 0.23, A ≈ 0.8,  ≈ 0.2,  ≈ 0.4

D. Brown, CKM phase and CP Violation in B Decays5 The Unitarity Triangle(s) l Graphical expression of unitarity condition(s) l 1 triangle has roughly equal-length sides l CKM Unitarity violation would imply New Physics l Test SM + CKM by over-constraining angles and sides   -i-i      

D. Brown, CKM phase and CP Violation in B Decays6 Consequences of CPV l CPV can occur when multiple B  F amplitudes interfere l CPV in decay (direct CPV) l CPV in mixing (original CPV seen in K S, K L ) l Very small for B system (exp. limit <10 -2, predicted ~10 -3 in SM) l CPV in mixing + decay (indirect CPV) l B system uniquely situated for CPV studies l Mixing, long lifetime, large production X-section, rich decay set, heavy quarks  theoretically accessible, … S2S2 S1S1 EW 1 EW 2    S2†S2† S1†S1† EW 1 † EW 2 † †≠†≠   CP  Direct CPV Mixing+Decay CPV F CP B0B0 B0B0 AFAF AFAF e -2i  B 0 and B  decay  0

D. Brown, CKM phase and CP Violation in B Decays7 Detecting Indirect CPV in B-decays B  f CP exclusive reconstruction  ~10% e-e- Flavor tagging Q≈30% at B-factories ≈few % at Tevatron  (4S)  B 0 (b) e-e- ++ -- e+e+ ++ -- K-K-  z≈  c  t Coherent evolution mixing B-factories

D. Brown, CKM phase and CP Violation in B Decays8 The B-factories Asymmetric e + e - colliders make boosted  (4S)  c  B ~200  m in the lab frame l General-purpose detectors l Tracking EM calorimetery, muon system, PID,… l BaBar/PEP-II Total Sample ≈ 450 fb -1 l KEK-B/Belle Total Sample ≈ 700 fb -1 l Data sets have increased ~10% in the last year l Many new results from data ‘backlog’! l Tevatron Run2 results on ≥1fb -1 coming out now

D. Brown, CKM phase and CP Violation in B Decays9 Beta         B0B0 B0B0

D. Brown, CKM phase and CP Violation in B Decays10 B 0  charmonium K 0 : b  c  cs  f = CP eigenvalue = -1(K S ),+1(K L ) l SM decay dominated by a single tree diagram l Leading order (Tree) diagram has no weak phase asymmetry directly measures  Higher-order diagrams are smaller by factor ~ O (10 -2  ) l most have same EW phase l BF ≈10 -3 (color suppressed) SM expectation: S = -  f sin2  C≈0 No EW phase 

D. Brown, CKM phase and CP Violation in B Decays11 B 0  charmonium K 0 : b  c  cs l Easily reconstructed final states Charmonium  l + l - has high efficiency, low background K S  +  - easily recognized in tracking detectors l Strong kinematic variables separate B from background l M B constrained to known beam energies to improve resolution  E  E B -E beam is an independent kinematic variable N B  B = 535M N sig = 7484±87 M B (GeV/c 2 ) background PRL 98, (2007) hep-ex/ N B  B = 383M N sig = 4748 Purity=55% background 

D. Brown, CKM phase and CP Violation in B Decays12 sin2  in B 0 → charmonium K 0 : b  c  cs BaBar Preliminary (hep-ex/ ) N B  B = 383M PRL 98, (2007) N B  B = 535M B 0 tags  B 0 tags  f  t (ps)  t (ps) J/  K S J/  K L background 

D. Brown, CKM phase and CP Violation in B Decays13  from B 0 → charmonium K 0 : b  c  cs Sets the gold standard for CPV measurements Sin2  =0.678±0.026 New world average 95%CL contours 2-fold ambiguity resolved by several cos2  measurements B 0 → D 0 3-body h 0 Dalitz Analysis (BaBar) B 0 → K S  +  - Dalitz Analysis (BaBar) B 0 → K S K + K - Dalitz Analysis (BaBar) S f = sin2   + older results on B 0 → J/  K*, … new

D. Brown, CKM phase and CP Violation in B Decays14 B 0 → D + D - : b → c  cd B0B0 D-D- D+D+ B0B0 D-D- D+D+ l Two decay amplitudes interfere b → c tree diagram with S = -sin2  l b → d penguin diagram with S ~ 0 l Penguin is expected to be small l ~2-10% (PRD 61, , 2001) l Larger backgrounds Standard Model predicts: Y. Grossman and M. Worah, Phys. Lett. B 395, 241 (1997)   NP particle can enter in loop

D. Brown, CKM phase and CP Violation in B Decays15 S and C in B 0 → D + D - : b → c  cd B 0 tags  B 0 tags Agreement on C has CL=0.003 ⇒ >3.0σ discrepancy Belle claims evidence for direct CP violation at 3.2  hep-ex/ N B  B = 535M N sig =128±14 background PRL 98,221802(2007) S C (0,0) C CP (B 0  D + D - ) = ± 023 ± 0.06 C CP (B 0  D + D - ) = +0.11± 022 ± 0.07 New Belle Result: N B  B = 383M N sig =131±14  Preliminary A CP (B +  D + D 0 ) = 0.01 ± 0.08 ± 0.02 BELLE-CONF-0762

D. Brown, CKM phase and CP Violation in B Decays16 CPV in B 0 → D* + D* - : b → c  cd l Same diagram as B 0 → D + D -,but Vector-Vector final state  f (CP) depends on helicity, analyzed using D* decay angles N B  B = 383M N sig =617±33 background hep-ex/  BaBar preliminary

D. Brown, CKM phase and CP Violation in B Decays17 S and C in b → c  cd Silver modes: generally good agreement with golden mode S= -sin2  C=0 -S f CfCf sin2  

D. Brown, CKM phase and CP Violation in B Decays18 Purely Penguin decays: b  s  qq l No tree-level contributions l New Physics can enter at equal order as SM l SM predicts same EW phase as b → cW - Comparison with charmonium sin2  provides a direct test for NP l Many accessible modes l NP might couple to some or all l More challenging experimentally l BF ~10 -5, large backgrounds from continuum New Physics SM  s qq q s qq q SUSY,… 

D. Brown, CKM phase and CP Violation in B Decays19 B 0 → K S  0  0 :b  s  qq (Jet-like) (Spherical) LR>0.9 LR  E(GeV) M B (GeV/c 2 ) LR>0.9, good tag N sig = 307±32 N B  B = 657M S =+0.43 ± 0.49 ± 0.09 C=+0.17 ± 0.24 ±  from the SM expectation S= -sin2    B 0 tags B 0 tags  t (ps) Preliminary BELLE-CONF-0723

D. Brown, CKM phase and CP Violation in B Decays20 B 0 → K S  +  - :b  s  qq 2.1  > 2  from charmonium B 0 → K S   (770) B 0 → K S f 0 (980) 2-fold  ambiguity (partially) resolved l Measure TDCPA at each point on the Dalitz plot Include interference between  +  -, K S  ± resonances  0, f 0,K*, … Supersedes previous results on B 0 → K S  ,K S f 0 l + Direct CPV in B 0 → K* +    relative phases 2  eff 22 22  hep-ex/????

D. Brown, CKM phase and CP Violation in B Decays21 sin2  in b  s  qq Penguins New naïve HFAG average <1  from the naïve golden mode sin2  value  New/Updated BaBar/Belle Result                  sin2  S f = -sin2  eff 1% CL for the average

D. Brown, CKM phase and CP Violation in B Decays22 Alpha           l In principle measurable using any b  u dominated B 0  f CP l Very rare decays! BF~10 -6 In practice, penguin modes have similar magnitude, different EW phase  extracting  is a challenge!

D. Brown, CKM phase and CP Violation in B Decays23 B 0 →  +  - : b  u  ud PRD 75 (2007) N B  B = 383M N sig = 1139±39 B 0 tags  B 0 tags N B  B = 535M N sig = 1464±65 PRL 98, (2007) 2.1  tension in C   B 0 tags B 0 tags 

D. Brown, CKM phase and CP Violation in B Decays24 Extracting  from B 0 →  +  - l CPV well established Problem: extract  from  eff l Solution: Isospin l Measure isospin-related modes l Rates and C/A CP (if possible) l Adds another discrete ambiguity! M. Gronau and D. London, Phys Rev. Lett. 65, 3381 (1990)  ±  °    ° BR(B 0 → π 0 π 0 ) = (1.47 ± 0.25 ± 0.12)×10 -6 C(B 0 → π 0 π 0 ) = ± 0.35 ± 0.05 BR(B ± → π ± π 0 ) = (5.02 ± 0.46 ± 0.29)×10 -6 A(B ± → π ± π 0 ) = 0.03 ± 0.08 ± 0.01 hep-ex: 

D. Brown, CKM phase and CP Violation in B Decays25 B 0 → a 1 +    : b  u  ud PRL. 97, (2006) PRL use SU(3) to relate states BF B 0 → K 1 +   BF and A CP in  B 0 → a 1 -   Next step: constrain  hep-ex/ α eff = 78.6°±7.3° N sig = 608 ± 53 N B  B = 383M N B  B = 535M N sig = 654 ± 70 background M B (GeV/c 2 ) First TDCPV analysis of a 1 +    B 0 tags B 0 tags  B 0 → K 1 +   l Large signal observed l significant background

D. Brown, CKM phase and CP Violation in B Decays26 B 0 →  0 : b  u  ud l Vector+Vector final state l Analyze helicity to separate CP admixture as in B 0 → D* + D* - Use Isospin triangle to constrain  as in  N B  B = 383M hep-ex/ N B  B = 535M PRD76, (R) (2007) C = 0.01 ± 0.15 ± 0.06 S = ± 0.20 f L = ± N sig =729 ± 60 TDCPV in      t (ps) 

D. Brown, CKM phase and CP Violation in B Decays27 The critical side: B 0 →    0 First TDCPV analysis of    0 ! N B  B = 427M L sig / L sum N sig = 85 ± 27 ± 17 BaBar Preliminary N B  B = 520M  t (ps) M B GeV/c 2 M  GeV/c 2 N sig =34±16 BELLE-CONF-0747 Preliminary  signal hep-ex/

D. Brown, CKM phase and CP Violation in B Decays28 Constraining  using b  u  ud  BaBar Preliminary  B 0 → (  0 °°

D. Brown, CKM phase and CP Violation in B Decays29 Gamma          B +,B - rate asymmetry (DCPV) is sensitive to  The problem: How to distinguish EW phase from strong phase? Can also measure 2  +  via TDCPV in B 0  D +  -,+ B-B- B-B- D0D0 D0D0 K-K- K-K-

D. Brown, CKM phase and CP Violation in B Decays30  from B ±  D 0 K ± l Three Answers D 0 decays to 2-body CP eigenstates (K + K -,  +  -,…) GLW l large + unknown asymmetry in B +,B - BFs D 0 decays to non-CP eigenstates (K +  -, K +  -  0,…) ADS l Better match in rates (Cabbio suppression enhances interference) D 0 decays to 3-body (K 0 S  +  - ) GGSZ l Uses (~known) variation of resonance strong phase across Dalitz plot l Requires detailed model of resonant substructure l All methods have (varying) weakness due to unknown or under-constrained parameters  Constrain  by combining results from all methods GLW  Gronau, London (1991),Gronau, Wyler (1990) ADS  Atwood, Danietz, Soni (1997) GGSZ  Giri, Grossman, Soffer, Zupan (2003) GLW  Gronau, London (1991),Gronau, Wyler (1990) ADS  Atwood, Danietz, Soni (1997) GGSZ  Giri, Grossman, Soffer, Zupan (2003) 

D. Brown, CKM phase and CP Violation in B Decays31 Combined constraint on  Includes a new preliminary result: B ±  D 0 K ± GLW (BaBar)  °°  = 88 ± 16 °

D. Brown, CKM phase and CP Violation in B Decays32 The Unitarity Triangle: angles only

D. Brown, CKM phase and CP Violation in B Decays33 The Unitarity Triangle: all constraints A consistent picture across a huge array of measurements

D. Brown, CKM phase and CP Violation in B Decays34 B s  J/  (  s ): b  c  cs l Same quark decay as B 0  charmonium K 0 l B s mixing goes as V ts  ~ no CPV phase as in B d mixing SM prediction of  s = 4.2 ± 1.4X10 -3 Hep-ph/ Simultaneous fit to  s,  s Consistent with SM

D. Brown, CKM phase and CP Violation in B Decays35 Direct CPV in charmless B Decays K +  - ~8  A K  (B d )=−0.095 ± (WA) A K  (B +  K 0   )=0.009 ± A K  (B +  K +   )=0.050 ± Effect from EW penguins?  K*   K  K +    Isospin analogs

D. Brown, CKM phase and CP Violation in B Decays36 Direct CPV in B s Decays A K  (B s )=0.39 ± 0.15 ±  significance H.J.Lipkin, Phys. Lett. B 621, 126 (2005) Consistent with SM prediction ≈1.0 Comparing A K  (B d, B s ) A K  (B d ) = ± ±  significance

D. Brown, CKM phase and CP Violation in B Decays37 Conclusions l Standard Model CKM CPV is well established l Confirmed by many analyses, several experiments l Unitarity angle precision continues to improve Sin2  is still statistics limited! l New, innovative techniques are still being developed l CPV provides a unique window on the SM l Data constrain the unsolved problems of flavor/ generation mixing, matter-anti-matter asymmetry l The existing B-factories will soon be turned off l BaBar,Belle complete in ~2008,Tevatron in ~2009 l Look for final analyses in ! l Future flavor physics depends on future facilities l LHCB, super-B, super-Belle, …

BACKUP

D. Brown, CKM phase and CP Violation in B Decays39 The B-factories KEK-B Belle PEP-II

D. Brown, CKM phase and CP Violation in B Decays40 Datasets Total = ≈ 700 fb -1 KEK-B BELLE Pep-II BaBar Total ≈ 450 fb -1

D. Brown, CKM phase and CP Violation in B Decays41 B 0 → J/  0 : b → c  cd l Enhanced sensitivity to higher-order (penguin) diagrams l Cross-check on assumption that C gold ≈0  290 J/ψπ 0 candidates Purity=88±7% N B  B = 535M M B (GeV/c 2 ) hep-ex/ (submitted to PRD.RC) M.Ciuchini,M.PieriniandL.Silvestrini,Phys.Rev.Lett95,221804(2005) S=−0.65 ± 0.21± 0.05 C= ± 0.16 ± 0.05 S C (0,0) NP particle can enter in loop 

D. Brown, CKM phase and CP Violation in B Decays42 B 0 → D* +- D -+ : b → c  cd l Final state not a CP eigenstate l Could show time-integrated charge asymmetry l TDCPA modified by strong phase difference (S +- ≠ S -+, C +- ≠ C -+ ) If penguin contribution is zero, C -+ = -C +-,  eff =  If S -+ = -S +-,No CPV  sin(2  eff ) = 0 

D. Brown, CKM phase and CP Violation in B Decays43 S and C in B 0 → D* +- D -+ : b → c  cd sin(2  cos  4  Hep-ex/ N B  B = 383M B 0 →D *+ D ± 19 signal events 219 ± 18 signal events B 0 →D *- D + Time-integrated asymmetry consistent with 0 No significant direct CPV 

D. Brown, CKM phase and CP Violation in B Decays44 B 0 → D 0 3-body h 0 : b → c  ud D 0 →K S  +  - = coherent ensemble of quasi 2-body decays l (Known) variation of strong phase over Dalitz plot allows extraction of strong and weak phase differences! l Must measure TDCPA at all points in the Dalitz plot 2-fold ambiguity on  can (in principle) be resolved N B  B = 383M BaBar Preliminary (update) N sig = 335 ± 32 hep-ex/???? 

D. Brown, CKM phase and CP Violation in B Decays45 B 0 → D 0 3-body h 0 Dalitz Analysis : b → c  ud B 0 tagged  B 0 tagged h 0 =  0,  ( ' ),  cos2  >0 at 84% CL Asymmetry K* + K* - 00 BaBar Preliminary 

D. Brown, CKM phase and CP Violation in B Decays46 B 0 → K S K + K - :b  s  qq l Measure TDCPA at each point on the Dalitz plot l Includes interference between K + K -, K S K ± resonances  hep-ex/ A CP = −0.015 ± ±  eff = ± ± rad 4.8  significance

D. Brown, CKM phase and CP Violation in B Decays47 B 0 → D 0 CP h 0 :b → c  ud l b → c  ud tree dominates l b → u  cd suppressed ~1/50 l D 0 CP  D 0 → KK, K S  also D* 0 → D 0 CP   l h 0     First TDCPA in these modes! SM predicts S=-sin2 , C≈0 N B  B = 383M N sig =335±32 hep-ex/  background

D. Brown, CKM phase and CP Violation in B Decays48 N B  B = 657M B 0 → K S K S :b  d  ss R. Fleischer and S. Recksiegel, Eur.Phys.J.C38: ,2004 Entries/2.5ps Raw Asymmetry S =  0.77  0.08 C =  0.38  0.05 S =  0.77  0.08 C =  0.38  0.05 N signal =33±6 d SM expectation:S≈0,C≈0 K 0 V td S C (0,0) EW decay phase cancels mixing phase  No CPV expected! B0B0  K 0  B 0 tags B 0 tags BELLE-CONF-0723 BaBar result PRL 97 (2006)  A.K.Giri and R.Mohanta, JHEP,11,084(2004) background

D. Brown, CKM phase and CP Violation in B Decays49 l No phase-space overlap between a 1 +, a 1 -, and a 1 0 l Can use SU(3) to relate p  K and a 1  K 1A Necessary BFs are measured,  not yet computed Constraining  in B → a 1  via SU(3) Gronau & Zupan, Phys. Rev. D73, (2006) B 0 → K 1 +   B 0 → a 1 -   BF(B 0  a 1 - K + )BF(a 1 -  +  -  - ) = 8.2 ± 1.5 ± 1.2 X10 -6 A ch (B 0  a 1 - K + )= ± 0.12 ± 0.01 BF(B +  a 1 + K 0 ) BF(a 1 +  +  +  - ) =17.4± 2.5 ± 2.2 X10 -6 A ch (B +  a 1 + K 0 ) =0.12± 0.11 ± 0.02 BaBar Preliminary BF(B 0  K 1 + (1270)  - ) = 12.0 ± X10 -6 BF(B 0  K 1 + (1400)  - ) = 16.7 ± X10 -6 M B GeV/c 2 M K  GeV/c 2 

D. Brown, CKM phase and CP Violation in B Decays50 B 0 →         : b  u  ud Can use Isospin as in  +  - l ‘pentagon’ relationship -> more terms to measure l New method: use (known) resonance phase variation over Dalitz to analyze EW phase l Eliminates some ambiguities Monte Carlo B 0 →ρ - π + B 0 →ρ + π - B 0 →ρ 0 π 0 Monte Carlo Interference Region. ρ+π-ρ+π- ρ-π+ρ-π+ ρ0π0ρ0π0 

D. Brown, CKM phase and CP Violation in B Decays51 B 0 →         : b  u  ud PRL 98, (2007) N B  B = 449M TDPA + isospin TDPA only N(B 0 →π + π - π 0 ) =2067 ± 86 A ρπ (ρ ± π ∓ ) =-0.14 ± 0.05 ± 0.02 C (ρ ± π ∓ ) =0.15 ± 0.09 ± 0.05 S (ρ ± π ∓ ) =-0.03 ± 0.11 ± 0.04 ΔC (ρ ± π ∓ ) =0.39 ± 0.09 ± 0.09 ΔS (ρ ± π ∓ ) =-0.01 ± 0.14 ± 0.06 C 00 (ρ 0 π 0 ) =-0.10 ± 0.40 ± 0.53 S 00 (ρ 0 π 0 ) =0.02 ± 0.22 ± °132° 87° hep-ex/ N B  B = 383M 

D. Brown, CKM phase and CP Violation in B Decays52 GLW results CP-even: D  K + K −,  +  − CP-odd: D  K S  0, K S , K S  4 observables, 3 unknowns 

D. Brown, CKM phase and CP Violation in B Decays53 ADS results A ADS =−0.22 ± 0.61 ± observables, 5 unknowns 

D. Brown, CKM phase and CP Violation in B Decays54 GGSZ Results x + = r B cos(  B +  ), y + = r B sin(  B +  ) x − = r B cos(  B −  ), y − = r B sin(  B −  ) Gaussian Variables Similar for Y +,Y - Physical Variables  r B,  B,  Modes in D KK  ( * ) K ( * ) 

D. Brown, CKM phase and CP Violation in B Decays55 CPV in  (4S) Decay If large, would invalidate sin2  from TDCPA results l Method: partial reconstruction Partial reconstruction Full reconstruction ++ -- KSKS J/  ++ -- ++ -- J/  c KSKS  (4S) B0B0 Br(  (4S)  B 0 B 0  J/  K S +J/  (  c )K S )  4x10  7 (90%C.L.) N sig = events +3.6 B0B0 N B  B = 535M SM expectation: ~1.4x10 -7 arXiv: (submitted to PRL)

D. Brown, CKM phase and CP Violation in B Decays56 How this all started... In the early universe, for every billion ordinary particles annihilating with antimatter, one was left standing… CKM CPV is too small to account for observed matter/anti-matter asymmetry by a factor of ~ Due to ‘Heavy’ Higgs, 12 factors of lambda for simplest process resulting in matter/anti-matter asymmetry

D. Brown, CKM phase and CP Violation in B Decays57