Testing QCD factorization and charming penguin diagrams in charmlessB→PV

Abstract

We try a global fit of the experimental branching ratios and CP-asymmetries of the charmless B → P V decays according to QCD factorisation. We find it impossible to reach a satisfactory agreement, the confidence level (CL) of the best fit is smaller than .1 %. The main reason for this failure is the difficulty to accomodate several large experimental branching ratios of the strange channels. Furthermore, experiment was not able to exclude a large direct CP asymmetry in B 0 → ρ + π − , which is predicted very small by QCD factorisation. Trying a fit with QCD factorisation complemented by a charming-penguin inspired model we reach a best fit which is not excluded by experiment (CL of about 8 %) but is not fully convincing. These negative results must be tempered by the remark that some of the experimental data used are recent and might still evolve significantly. *

Charming penguin contributions inB→K*π,K(ρ,ωIsola1, Ladisa2, Nardulli3 et al. 2003Phys. Rev. D20931640View full textAdd to dashboardCite

“…B(B 0 → K + ρ − ) = 12.1. The authors of [30] do not agree with the conclusions of Du et al, Ref. [46], because, differently from them, they include the K * π channels.…”

“…These are long distance contributions known in the literature as charming penguin diagrams [25,26,27,28,29,30]. Induced by the non leptonic hamiltonian ∝ V * cb V csb γ µ (1 − γ 5 )ccγ µ (1 − γ 5 )s + Fierz + h.c., they cannot contribute in the vacuum saturation approximation.…”

“…For the real part of the amplitude, R LD , we assume a simple parametrization R LD ∝ I LD , fixing the two proportionality constants (one for each of the SU(3) f multiplets comprising the light vector mesons) by a fit. A similar calculation has been recently attempted by [30]; these authors assume a more phenomenological approach and parametrize the amplitude in the more general way (two complex numbers), using SU (3) flavor symmetry to relate the different amplitudes. Therefore our calculation can provide a dynamical test of the model in [30].…”

Power corrections in charmless B decays

“…Other power corrections terms such as annihilation contributions may also be present in PP and PV decays as first noticed in the perturbative QCD method for charmless B decays [2] and indicated by recent analysis of charmless two-body non-leptonic B decays [3,4,5]. In a recent work [6], we have shown that in QCDF, it is possible to consider certain ratios of the B → P V amplitudes which depend only on the Wilson coefficients and the known hadronic parameters.…”

Relations for Direct CP asymmetries in B → PP and B → PV decays

“…Other power corrections terms such as annihilation contributions may also be present in PP and PV decays as first noticed in the perturbative QCD method for charmless B decays [7] and indicated by recent analysis of charmless two-body non-leptonic B decays [8,9,10]. In a recent work [11], we have shown that in QCDF, it is possible to consider certain ratios of the B → P V amplitudes which depend only on the Wilson coefficients and the known hadronic parameters.…”