Final state interactions in hadronicBdecays

Abstract

There exist many experimental indications that final-state interactions (FSIs) may play a prominent role not only in charmful B decays but also in charmless B ones. We examine the final-state rescattering effects on the hadronic B decay rates and their impact on direct CP violation. The color-suppressed neutral modes such as B 0 → D 0 π 0 , π 0 π 0 , ρ 0 π 0 , K 0 π 0 can be substantially enhanced by long-distance rescattering effects. The direct CP -violating partial rate asymmetries in charmless B decays to ππ/πK and ρπ are significantly affected by final-state rescattering and their signs are generally different from that predicted by the short-distance approach. For example, direct CP asymmetry in B 0 → ρ 0 π 0 is increased to around 60% due to final state rescattering effects whereas the short-distance picture gives about 1%. Evidence of direct CP violation in the decay B 0 → K − π + is now established, while the combined BaBar and Belle measurements of B 0 → ρ ± π ∓ imply a 3.6σ direct CP asymmetry in the ρ + π − mode. Our predictions for CP violation agree with experiment in both magnitude and sign, whereas the QCD factorization predictions (especially for ρ + π − ) seem to have some difficulty with the data. Direct CP violation in the decay B − → π − π 0 is very small ( < ∼ 1%) in the Standard Model even after the inclusion of FSIs. Its measurement will provide a nice way to search for New Physics as in the Standard Model QCD penguins cannot contribute (except by isospin violation). Current data on πK modes seem to violate the isospin sum rule relation, suggesting the presence of electroweak penguin contributions. We have also investigated whether a large transverse polarization in B → φK * can arise from the final-state rescattering of D ( * )D ( * ) s into φK * . While the longitudinal polarization fraction can be reduced significantly from short-distance predictions due to such FSI effects, no sizable perpendicular polarization is found owing mainly to the large cancellations occurring in the processes B → D * sD → φK * and B → D sD * → φK * and this can be understood as a consequence of CP and SU(3) [CPS] symmetry. To fully account for the polarization anomaly (especially the perpendicular polarization) observed in B → φK * , FSI from other states or other mechanism, e.g. the penguin-induced annihilation, may have to be invoked. Our conclusion is that the small value of the longitudinal polarization in V V modes cannot be regarded as a clean signal for New Physics.

Phenomenological analysis of the decay $$B^{\pm }\rightarrow K^{\pm } p {\bar{p}}$$ B ± → K ± p p ¯

“…The situation is somewhat analogous to the one illustrated in Ref. [26] about the decays of B to K χ 0 , to D ( * )0 π 0 and to π 0 π 0 , which are surprisingly enhanced with respect to the factorization assumption and demand both non-factorizing terms and re-scattering effects.…”

“…Aside from that, as stated before, the long-range FSI might be not so negligible, somewhat analogously to the case of B decays to mesons [26], although on a smaller scale. This may contribute to the failure of factorization and may give rise to further effects, to be discussed in Sect.…”

Improved method for CKM constraints in charmless three-bodyBandBsdecays

“…The error from neglecting a strong phase difference between A ρ + π 0 and A ρ 0 π + is expected to be very small, since Re(r 3/2 ) depends quadratically on this phase. This is gratifying since the size of 1/m b suppressed strong phases cannot be reliably calculated [18,25]. Information on the above phase is provided by the isospin pentagon relation [3],…”

Hadronic loop contributions to J/ψ and ψ′ radiative decays into γLi1, Zhao2 2008Physics Letters B430161View full textAdd to dashboardCite

“…In the recent years, the intermediate meson loop is investigated in a lot of meson decay channels [8,9,10,11,12,13,14,15,16] as one of the important non-perturbative transition mechanisms, or known as final state interactiions (FSI). In particular in the energy region of charmonium masses, with more and more data from Belle, BaBar, CLEO-c and BES, it is widely studied that intermediate meson loop may account for apparent OZI-rule violations [11,12,13,14,15,16] via quark-hadron duality arguement [17,18,19].…”