Reaching for  (present and future) Andrey Golutvin ITEP/Moscow Reaching for  (present and future)

 = arg | | Unitarity Triangles This talk V ud Vub* -V cd Vcb* Bd0  p+ p- Bd0  r p Bd0  DK*0 BS0  DSK Bd0  D* p, 3p BS0  DS p Bd0  J/y KS0 BS0  J/y f This talk  = arg | | V ud Vub* -V cd Vcb*

CP violation in Interference of There are a few methods of determining  CP violation in Interference of Mixing & Decay CP violation in Decay Rates and asymmetries in K Decays Amplitude triangles for B Dcp0K (GLW method) + extensions/modifications Time dependent asymmetries in Bd+- and BsK+K- decays assuming U-spin symmetry Time dependent flavor tagged analysis of BsDsK- decay BdD*+ decay

Data Samples (present and future) Results presented today are based on 81.2 fb-1(BaBar) and 78 fb-1(BELLE) That corresponds to 88 and 85 mln BB pairs (part of data sample) Statistics available today at B-factories  300 mln BB pairs - - - In 2006 one expects  1.2 bln BB pairs - In 2008 after 1 year of LHCb (and BTeV) operation  1012 bb pairs Super Bd-factory: 1.5 to 5 bln of “clean” BB events depending on achieved luminosity -

g from B  K decays Difficulties: Theoretical EW penguins Significant interference of tree and penguin amplitudes Expect potentially large CP asymmetries QCD penguins play the dominant role Difficulties: Theoretical EW penguins SU(3) breaking + (FSI) effects Experimental small BF, qq background Particle ID is crucial Measurement of the ratios of BF and ACP may provide constraints on  and strong phase  dir _

Summary of BFs [10-6] From J.D. Olsen talk at the CKM workshop 2003

Comparison of BF No sign of rescattering yet Present precision is dominated by statistical errors In a few years statistical and systematical errors should become comparable

A Specific Model: QCD Factorization Beneke et. al., Nucl. Phys. B606, 245 (2001) Data (2001) Data (2003) Inconsistent? Data start to constrain models

CP asymmetries (allows one to eliminate dependence on the strong phase ) Largest deviations: 2s each in K+p-(BaBar), r+p-(BaBar), and K+p0(Belle)

uncertainties In 1 year BTeV expects: In a few years statistical precision in the measurements of Branching Fractions (BK/) should reach the level of systematic error, 2-4% depending on decay mode Extraction of  will be dominated by theoretical uncertainties BaBar: K0+ 80 fb-1 In 1 year BTeV expects: 4600 K0+ events (with S/B = 1) 62100 K-+ events (with S/B=20)

Amplitude triangles GLW method B-  DCPK- where DCP=(1/2)(D0 D0 ) A(B-  DCPK-)  |A(B- D0K- )| + |A(B- D0K- )|eiei A(B-  DCPK+)  |A(B- D0K+ )| + |A(B- D0K+ )|e-iei CP-even states: K+K-, +- CP-odd states: Ks0, Ks, Ks, Ks, Ks’

 can be extracted from the reconstruction of two triangles Experimental problems: A(B-D0K-) is small squashed triangles DCSD lead to the common final states for D0 and D0 (color suppressed A is of the same order as color favored  DCSD) Experimental observables: BF(B-D1,2K-) / BF(B-D1,2-) , A1 and A2 R1,2 = BF(B-D0K-) / BF(B-D0-) allow, in principle, to extract RDK- ,  and 

No constraints on  possible with this statistics … BaBar reconstructed D1K- K+K- (7.41.70.6)% R1= (8.310.350.20)% +0.09 AD1K- = 0.170.23 -0.07 BELLE studied both D1K-and D2K- R1 = 1.21  0.25  0.14 R2 = 1.41  0.27  0.15 AD1K-= +0.06  0.19  0.04 AD2K-= -0.18  0.17  0.05 No constraints on  possible with this statistics … Needed: significantly higher statistics precision measurements of D Branching Fractions

Triangles are not as squashed B0D0K(*)0 Mode Two comparable color-suppressed amplitudes Triangles are not as squashed as in B DK case _ _ BELLE +1.3 BF(B0 D0 K0) = (5.0 0.6)  10-5 -1.2 _ _ +1.1 BF(B0 D0 K*0) = (4.8 0.6)  10-5 -1.0 Hope to see soon B0 D0 K*0 decay Present Upper Limit is BF(B0 D0 K*0)  1.8  10-5

KS+- receives contributions from: ADS variant of the amplitude triangle approach: B-  D0[fi] K- and B-  D0[fi]K-, fi= K-+ or K-+0 Use large interference effects Experimentally challenging since BF of O(10-7) are involved Dalitz plot analysis of D  KS+ - for B-DK- and B+DK+ decays KS+- receives contributions from: B- D0K- D0K*-+ K*- KS- B- D0K- D0K*+- K*+ KS+ B- D0K- D0KS0 0  +- Enough information to extract  for any magnitude of 

B0D*- Mode (2 + ) is extracted from the measurement of _ u c + D*- _ favored suppressed d d _ _ b c b u _ B0 + B0 D*- _ _ d d d d Suppressed/favored < 10-2 Small CP-violating effect expected Time evolution: (BD*)  (1+RD*2)  (1-RD*2)cos(mt)  2 RD*sin(2+) sin(mt) (2 + ) is extracted from the measurement of 4 time-dependent asymmetries RD* can be estimated using BF(B0Ds+-): BF(B0Ds+-)  BF(B0D*-+) fDs2 RD*2   tan2c fD*2

Evidence for B0Ds+- RD*  0.022  0.007 Br(B0Ds+-)Br(Ds++) BaBar (1.13  0.33  0.21)x10-6 BELLE (0.86  0.11) x10-6 +0.37 -0.30 BELLE have measured Br(Ds++)=(3.720.39 ) x10-6 using full/partial reconstruction method +0.47 -0.39 RD*  0.022  0.007

D*+- Data Samples (partial reconstruction) 20 fb-1, 6970 ± 240 events B0 = 1.510 ± 0.040 ± 0.041 ps 30 fb-1 , 3430 ± 80 events m = 0.509 ± 0.017 ± 0.020 ps-1 (sin(2+))   0.15 for 1000 fb-1 T. Gershon (CKM workshop, 2003) or (2+)  10o

g from Bs  D-s K+ , D+s K- Looks as most clean method to measure  Same principle as for B0D*- Since  is small  sensitivity should not depend on the value of  Two decay modes with comparable amplitudes,   10-4 each  can be determined from the measurement of 4 time-dependent asymmetries (assuming that  is fixed from Bs mixing) Contribution from NP is unlikely ! Looks as most clean method to measure 

Bs  Dsp, DsK kinematics at LHCb  Ds 72k Ds  8k Ds K  ~ 6.5 MeV/c2 s = 168 mm s = 418 mm Ds mass (GeV) Bs vtx resolution (mm) Ds vtx resolution (mm)

Importance of Particle ID Needed: Hadronic trigger K/p separation Good proper time resolution

Sensitivity slightly depends on strong phase difference (T1/T2) In one year of LHCb running: 8k BsDsK reconstructed events Sensitivity slightly depends on strong phase difference (T1/T2) and xs Assumptions: 3k tagged BsDsK- 30% background 30% mistag LHCb: ()  10º for xs = 15 ()  12º for xs = 30 BTeV: ()  8º

where dexp(i) is a function g from B(s) p p, K K proposed by R. Fleischer Measure time-dependent asymmetries in B0  +- and Bs  K+ K- decays to extract  where dexp(i) is a function of T and P amplitudes Assuming U-spin flavor symmetry: d=d’ and =’  can be extracted

g from B(s) p p, K K BS  K+ K- BS  K+ K- B0  + - B0  + - yield 27k 35k B/S 0.8 0.55 xq 0.755 20 D2 0.064 -0.30 0.16 0.58 -0.17 DG 0.0 input values Evaluation of and sensitivity from time-dependent measured asymmetry B0  + - BS  K+ K-

B0  + - BS  K+ K- Combining all information: () = 2.50 In one year of LHCb operation : BS  K+ K- increasing xs  B0  + - (A dir )  (A mix )  0.054 BS  K+ K- (A dir )  (A mix )  0.043 Sensitivity to : assuming 4 years of data taking (4x27k Bd and 4x35k BsKK) B/S = 0.8 and 0.55 correspondingly tagging: D2 = 6.4% Combining all information: () = 2.50

Sensitive probe for New Physics Conclusions  can be measured both using CPV in decay (time-integrated) and in the interference of mixing and decay (time-dependent) Only trees (1) Theoretically clean: b c X Amplitude triangles BsDsK Trees + loops (2) Experimentally easier b  hh (h = non-c) Experimental precision on BF already below 10% level Clear theoretical strategy how to extract  is still missing Measurement of rare decays with BF  10-7could help Sensitive probe for New Physics (1) vs (2)

ACP=ACP(dir)cos(mt) + ACP(mix)sin(mt) Expectations from CDF Run IIa ACP=ACP(dir)cos(mt) + ACP(mix)sin(mt) /K/KK/K separation: Inv. mass ~ 20 MeV/c2 Kinematical variables dE/dX Md << Ms —sum BdK BsKK Bd  BsK  RunIIa: ACP(dir, mix)~0.2 (Bd) ~0.1 (BsKK) () = ±10(stat)