Measurements of sin(2b + g) / sin(2f1 + f3) Belle BaBar Results from and Guillaume Therin LPNHE – Paris XLème rencontres de Moriond Moriond EW 2005 Measurements of sin(2b+g)

CP violation in standard model CKM matrix Unitarity triangle VudVub * a/f2 VtdVtb * g/f3 b/f1 sin (2b) = 0.725 ± 0.037 HFAG ICHEP04 VcdVcb * Experimental constraints on a Need direct measurements of g Talk on time dependent analysis to constraint sin(2b+g) Experimental results on B0  D(*) p/r Partial reconstruction Full reconstruction B0  D(*)0K(*)0 branching ratio See P.Krokovny’s talk for a review of g measurements. http://ckmfitter.in2p3.fr Moriond EW 2005 Measurements of sin(2b+g)

CP violation in B0D(*)p/r g Favored b  c decay Suppressed b  u decay Strong phase difference Determines the sensitivity of the method CKM angle Large branching fraction for favoured decay (~3x 10-3) Small BR for suppressed decay (~10-6) Small CP violating amplitude r(D(*)p) ≡ r(*) = A(B0 → D(*)- p+) ≈ 0.02 Moriond EW 2005 Measurements of sin(2b+g)

Time-dependent decay rate distributions - K+ -s Tag B K+ U(4s) Reco B z Dt @ Dz/gbc + Dz Mixing-Decay interference ∞ P(B0 → D(*) p ,Dt) 1 C cos(Dmd Dt) + S sin(Dmd Dt) ± ± ± ± ± P(B0 → D(*) p ,Dt) 1 C cos(Dmd Dt) - S sin(Dmd Dt) ± ± ∞ ± C = 1 – r2 1 + r2 ≈ 1 neglecting terms in o(r2) S± ≈ 2r sin ( 2b+g ± d ) , |S±| 0.04 < ~ Measurements of S+ and S- determine 2b+g and d if r is an external input Experiment : tag the flavour of the B with lepton and kaon categories l+ K+ lepton tag kaon tag Moriond EW 2005 Measurements of sin(2b+g)

Possible CP violation on the tag side Long, Baak, Cahn, Kirkby, PRD68, 034010 Potential competing CP violating effects in B decays used for flavour tagging K+ K+ ’ + Kaon tag : expect CP violation comparable to signal → Modified time distributions signal side tag side ∞ P(B0 → D(*) - p+ ,Dt) 1 + C cos(Dmd Dt) + sin(Dmd Dt) [± 2r sin(2b+g+d) + 2r’ sin(2b+g±d’)] Kaon and other flavour tags Lepton tags Observables : S+, S- Observables a, b, c Moriond EW 2005 Measurements of sin(2b+g)

Measurements of sin(2b+g) Determination of r I. Dunietz, Phys. Lett. B 427, 179 (1998) Simultaneous determination of sin(2+) and r from time-evolution is not possible with current statistics  Need r as external inputs Estimate amplitude ratios from B0Ds(*)+- using SU(3) symmetry SU(3) r(D) = 0.020 ± 0.003 r(D*) = 0.015 ± 0.005 r(Dr) = 0.003 ± 0.006 Assuming several hypotheses : Assuming factorisation in SU(3) symmetry W-exchange and annihilation diagrams neglected without any theoritical errors Moriond EW 2005 Measurements of sin(2b+g)

B0→D*-p+: partial reconstruction Babar BaBar Collaboration,hep-ex/0408038 (previous reference) fast Lepton Tags 227MBB Find events with two pions and examine the missing mass mmiss Preliminary All available statistics Preliminary kaon Tags Signal Combinatoric BB Peaking BB Continuum D*r ACP= N(B0 tag) - N(B0 tag) N(B0 tag) + N(B0 tag) Preliminary Lepton Tags 18710 ± 270 lepton tags Mean value 70580 ± 660 kaon tags Moriond EW 2005 Measurements of sin(2b+g)

Measurements of sin(2b+g) B0→D*-p+: partial reconstruction (interpretation) Babar BaBar Collaboration,hep-ex/0408038 (previous reference) 227MBB Adding 30% theoretical error on r(D*p) for different hypotheses Using the Feldman Cousins method r-h plane whith experimental constraints on sin(2β+γ) and β (from BaBar). r = 0.015 ± 0.005 ± 0.005 1 - CL Preliminary 68 % 90 % Preliminary |sin(2β+γ)|>0.62 (0.35) @ 68 (90)%CL Moriond EW 2005 Measurements of sin(2b+g)

Measurements of sin(2b+g) B0→D*-p+: partial reconstruction (lepton tag) Belle Collaboration,hep-ex/0408106 154MBB SF : Sign(pfast) = Sign(l) OF : Sign(pfast) = - Sign(l) Preliminary Preliminary Preliminary Preliminary Preliminary Preliminary helicity angle calculated with psoft Fit : Signal + Background 2823 Same Flavour (SF) 10078 Opposite Flavour (OF) S+ = 0.035 ± 0.041 ± 0.018 S- = 0.025 ± 0.041 ± 0.018 Moriond EW 2005 Measurements of sin(2b+g)

Measurements of sin(2b+g) 110MBB Babar B0→D(*)-p+/r+: full reconstruction BaBar Collaboration,hep-ex/0408106 D*- p+ D*+ p- B → D* p ± ± D*- p+ D*+ p- 7611 ± 97 B → Dp 7068 ± 89 B → D*p 4400 ± 79 B → Dr Moriond EW 2005 Measurements of sin(2b+g)

Measurements of sin(2b+g) 154MBB B0→D(*)-p+: full reconstruction Belle Collaboration, PRL 93 (2004) 031802 D*p Dp Use kaon and lepton tags Estimation of CP violation on the tag side with B→D*l n D*+ p- D*- p+ Assuming δ = 0 or π (factorisation) : D*+ p- D*- p+ Moriond EW 2005 Measurements of sin(2b+g)

Summary of sin(2b+g) results with B0 → D(*)p/r 227 MBB 110 MBB 152 MBB 152 MBB Partially rec. Fully rec. Partially rec. Fully rec. a(D*p) –0.049 ± 0.031 ± 0.020 0.060 ± 0.040 ± 0.019 -0.034 ± 0.014 ± 0.009 –0.031 ± 0.028 ± 0.018 c(D*p) -0.019 ± 0.022 ± 0.013 0.044 ± 0.054 ± 0.033 –0.004 ± 0.028 ± 0.018 0.049 ± 0.040 ± 0.019 a(Dp) –0.032 ± 0.031 ± 0.020 –0.062 ± 0.037 ± 0.018 c(Dp) –0.059 ± 0.055 ± 0.033 –0.025 ± 0.037 ± 0.018 a(Dr) –0.005 ± 0.044 ± 0.021 c(Dr) –0.147 ± 0.074 ± 0.035 a = 2 r sin(2b+g) cos (di) c = 2 r cos(2b+g) sin (di) r(D) = 0.020 ± 0.003 r(D*) = 0.015 ± 0.005 r(Dr) = 0.003 ± 0.006 without any errors coming from theoretical hypotheses Moriond EW 2005 Measurements of sin(2b+g)

Interpretation of sin(2b+g) assuming SU(3) Assign 30 % theoretical error on r(D*p), r(Dp) and r(Dr) Bayesian approach www.utfit.org h 68 % 90 % 68 % 90 % r 2b+g |sin(2b+g)|>0.74 @68% CL Moriond EW 2005 Measurements of sin(2b+g)

Constraining sin(2b+g) with B0→D(*)0Ks bc amplitude bu amplitude r0 = A(B0 → D0 K0) ≈ 0.4 Small branching fraction for favoured decay (~3x 10-5) Large asymmetry B0D(*)0Ks with any D0 measures sin2b+g with time dependent analysis B0D(*)0K*0 with D0CP eigenstate measures g (self-tagging mode ,not this talk) For r0=0.4, an error of 0.5 on sin(2b+g) is expected with 550 MBB . Moriond EW 2005 Measurements of sin(2b+g)

Branching ratios of B0→D(*)0Ks 124MBB Babar 274MBB Branching ratios of B0→D(*)0Ks D0 mass sideband Preliminary mes (GeV) BaBar Collaboration,hep-ex/0408052 Belle Collaboration,hep-ex/0408108 B → D0 K0 B( ) = 6.2 ± 1.2 ± 0.4 B( ) = 3.72 ± 0.65 ± 0.37 B0 → D0 K0 B( ) = 3.18 ± 0.32 B0 → D*0 K0 +1.25 -1.12 B → D*0 K0 B( ) = 4.5 ± 1.9 ± 0.5 r0( ) < 0.39 @ 90% D0 K*0 Average of B0 and B0 Moriond EW 2005 Measurements of sin(2b+g)

Measurements of sin(2b+g) Conclusions Many different approaches to measure g have been investigated with similar sensitivity. Limits on | sin(2b+g) | with time dependent analysis were updated Measurements on sin(2b+g) still statistics limited. Some analyses need to be updated with all available statistics Need to estimate CP violation on the tag side to use completely kaon tag Results on g can be combined with other DK measurements (also no penguin contribution) With higher statistics, methods to constraint sin(2b+g) with B0 → D(*)0 Ks will play a role as well ( r ≈ 0.4 ) |sin(2b+g)|>0.74 @68% CL Assuming SU(3) symmetry www.utfit.org Moriond EW 2005 Measurements of sin(2b+g)

Measurements of sin(2b+g) SU(3) breaking and Dsp0 SU(3) has been proven to hold at a few % level for factorizable processes, but here the heavy meson is emitted and factorization does not hold Note that the use of the form-factors automatically assumes factorization In the future BR(D+p0) will be measured expected to be ~10-6 SU(2) partner of D+p- SU(3) partner of Dsp0  will be able to test SU(3) First search of BDsp0 Consistent with SU(2) prediction from Br(Dsp ) Br(BDsp0) = 1.6 10-5 Small statistics Annihilations around Br(BDsp0)<2.8 10-5@90% C.L. Moriond EW 2005 Measurements of sin(2b+g)

Measurements of sin(2b+g) W-exchange diagrams B0D(*)+p- has contributions also from W exchange Constrained by smallness of Br(B0Ds-K+)/Br(B0D-p+)=(1.4±0.5)10-2 c D(*)-, Ds(*)- d,s d,s p+,K+ u Unfortunately this sets a limit only on the annihilation on the cabibbo allowed process. Assuming it is the same is controversial Moriond EW 2005 Measurements of sin(2b+g)

D(*)+Ks : probing annihilations SU(2) partner of D0K+ Expected to be ~10-7 but could get large contributions from rescattering Br(B D+Ks) < xxx 10-6 Br(B D*+Ks) < 7 10-6 Note: Br(B D0K+) =(3.7±0.6)10-4 Br(B D*0K+)=(3.6±1.0)10-4 Moriond EW 2005 Measurements of sin(2b+g)

Avoiding colour suppression : B0→D±KSp± (88 MBB) bc amplitude bu amplitude mixing Method has two advantages : Avoids colour suppression in b→u Integrating over Dalitz plane removes ambiguities in eventual g extraction First experimental step complete : Branching fraction measurement Currently, Too few events for TD analysis 1/3 of events are NOT in the K* region D±K*± → Moriond EW 2005 Measurements of sin(2b+g)

Data samples collected with Belle and BaBar BELLE @ KEK-B Accelerator BaBar @ PEP-II Accelerator 350 fb-1 integrated luminosity 275 million BB events 254 fb-1integrated luminosity 227 million BB events Moriond EW 2005 Measurements of sin(2b+g)

Measurements of sin(2b+g) sin(2b+g) in Pictures No Interference  CP Violation CP Violation only in fully reconstructed B0: r  0 CP Violation in both tag and fully reconstructed B0s: r  0 and r’  0 r exaggerated (x5 expectation) to enhance visual effect Small values of r significantly reduce sensitivity of the method Moriond EW 2005 Measurements of sin(2b+g)