CKM03 workshop What I learnt R. Faccini
A. Datta D. London hep-ph/0303159 Beta D. London, N.&R. Sinha hep-ph/0207007 • Lots of importance is given to VV modes • Angular analysis could reveal new physics because there are T-odd coefficients (triple products v1xv2•v3) which are supposed to be present in absence of two phases with different weak phases • Separately for charged and neutral modes • Separately for B and B • This method allows to test and bound possible other diagrams; • New physics • Penguins/tree • Note: these methods are in addition to CPV in oscillation and direct CPV
VV modes (cont’d) • How : • for flavour eigenstates it is just a reparametrization of current analysis • For CP eigenstates time-dep analysis with 18 parameters • Which modes? • General criteria: to expect 0 TP in SM one needs to have all amplitudes with the same phase. This cannot happen if a meson is made of more combinations of quarks (e.g. r). In this case the problem is solved taking higher resonances (r’)
Ways to cos2b • Angular analysis in J/Y K* returns sin(d)cos(2b) • Fleisher suggests to use the sign of the strong phase from factorization • deFazio showed factorization does not hold in charmonium decays (cc0K) which means the argument from Fleisher does not hold • Kayser method (J/YK0 vs J/YK0) is still theoretically the best but it is not applicable • DDK seems to be the only possibility T.E.Browder et al., Phys.Rev.D61:054009,2000
s u d c c d b b b c d s g in charmless decays • Contributions from bu transitions bring a dependence of CPV from g • Measure g directly in direct CP asymmetries & B+ decay rates • Measure 2b+g with CPV in mixing • Two cases A1~l2c A2~l4c d sin2b+g: A2 doubly cabibbo suppressed D(*)- p+ u b u B0 B0 p+ D(*)- No theo hypothesis whatever d d A1~l3c A2~l3c sing: A2 colour suppressed K(*)+ D(*)0 u c B= D(*)0 B0 u u K(*)+ u u
u b sin2b+g in D(*)p • we do not know • We are currently using • But: • What is the error on this SU(3) symmetry? BaBar is currently quoting 30% … although form factors have only 10% • What are the possible contributions from annihilations? Br(DsK) seems to say A~0.1 Emissions • We might be better off quoting dl/l=14% s,d Ds+,D+ c BF (B0 D- p+) fDs2 p- B0 BF (B0 Ds+ p-) l2Dp d d tan2qC fD2
London,Sinha Phys.Rev.Lett.85:1807(2000) sin2b+g in D*r • The 18 parameters fit has been discussed as a mean also to observe new physics (5000 fully reco in current data sample) • Idea! Use the measured |l|(L=1) in D*r to estimate |l|(D*p) • On 100 fb-1dsin2b+g~0.35
Gronau,London Phys Lett B253, 483 (1991) DK : GLW • Measure B-D0K, B-D0K and B-D0CPK • In 100fb-1: • N(B-D0CPK)~25 (per eigenstate) • but how to get B-D0K ? Should investigate lepton D0 decays. Expect 14 events … basically impossible • Currently backing up to use R,d,g unknown
D.Atwood,Dunietz,A. Soni hep-ph 9612433 DK: ADS • Find B-[f]K- and B+[f]K+ where f is a mode where the Br(D0f)<<Br(D0f) • Relevant parameter • For instance in 100 fb-1 • N([K+p-,K3p,Kpp0]K(*)-)~30 • Q~0.5 (expected asymmetry) • More modes can be added • Backgrounds?
D. Atwood, A. Soni hep-ph/0206045 D0K0 • Do the time dependent analysis both for D0 in CP eigenstates or not • With the BF measured by Belle in D0Ks • N(Kp)~30 x 2 (D*0) • N(Ksp0)~3 • Very important: Kl modes are also very useful (add independent constraints) • N(Kp)~25 BUT A LOT OF BACKGROUND • Can we just do the direct CPV if non-CP eigenstates? No, don’t learn anything
D. Atwood, A. Soni, hep-ph/0304085 DK inclusive approaches • Both ADS and D0K0 can be done with inclusive approaches • B-[K+X]K-(p0 for D*0) N~800 Q~0.3 (!!! But what about bkgd?How to associate K+ to D0? Lepton tag -> down to 50 events) looks really tough!!! • B0[KsX]KsN~100 but it will be hard to make Dt measurements • B0 [K+X]KsN~600 • If we do not want to go for partial reco, X can be a list of modes (semi-exclusive approach) • It all looks very tough!!!
Soffer,Zupan hep-ph/0303187 D(dalitz)K- • A subsample of the previous class is the use of D dalitz plot. If one parametrizes the whole dalitz structure (from inclusive D) one can fit for sing. • Proposed mode f=Kspp • In 100 fb-1 we should have ~300 events
DKp • Direct CP in B- D0K-p0 • Measures g • Oscillations in B0 D0Ksp- • Measures sin(2b+g) • Advantages • Two amplitudes of same size • Disadvantages • Need to make sure there are interference regions • Need to know dalitz structure
a in 2-3 body “ the only hope is not to observe p0p0 and r0p0 “
bdg: an idea • bdg is a measurement that people would really like • One idea: • Consider the recoil (300K in 100fb-1) • Select events with a photon consistent with bsgand a Ks (N0) or a charged K (Nc) and estimate the pure b sg yield (and therefore BF) from • Use the sample without kaons to estimate bdg properly subtracting bsg background • To reject Kl one should try ascribing to each Kl (or only those”more likely to be Kl”) the mass of the Kl and see if the consistency with a B decays increases
Miscellanea • Tau polarization in Btln probes new physics • Forward –backwards asymmetry in Kll, Xsll,mll spectrum … all measurements that should be done!