B→Vγbeyond QCD factorization

Abstract

Abstract:We calculate the main observables in B u,d → (ρ, ω, K * )γ and B s → (K * , φ)γ decays, i.e. branching ratios and CP and isospin asymmetries. We include QCD factorisation results and also the dominant contributions beyond QCD factorisation, namely longdistance photon emission and soft-gluon emission from quark loops. All contributions beyond QCD factorisation are estimated from light-cone sum rules. We devise in particular a method for calculating soft-gluon emission, building on earlier ideas developed for analogous contributions in non-leptonic decays. Our results are relevant for new-physics searches at the B factories, the LHC and a future super-flavour factory. Using current experimental data, we also extract |V td /V ts | and the angle γ of the unitarity triangle. We give detailed tables of theoretical uncertainties of the relevant quantities which facilitates future determinations of these CKM parameters from updated experimental results.

Erratum:B→K1γdecays in the light-cone QCD sum rules [Phys. Rev. D77, 094023 (2008)]

“…Nevertheless, the resulting sum rule result for T BK * 1 (0) seems to be significantly larger than the estimate extracted from the data [37], although the sum rule result can be improved by including α s -corrections [35]. We have checked that using the physical value of f B , that we adopt here, in the T BK * 1 (0) LC sum rule with the same order in α s and m K 1 /m b , we get T BK * 1 (0) ≈ 0.25 +0.03 −0.02 which is in good agreement with the result constrained by the data [37,41]. Extracting from the data, the current estimation is T BK * 1 (0) = 0.267±0.018 [41].…”

Future prospects for the determination of the Wilson coefficient $ C_{{^{{7\gamma }}}}^{\prime } $

“…More specifically, for the B → K * (→ K S π 0 )γ decay, the SM prediction reads [39] 4) which is to be compared with the current world average for the asymmetry in the B →…”

Higgs decay width in multiscalar doublet models

“…6 For exclusive decays there can be interference between the standard model contribution and the contribution of the effective Hamiltonian in Eq. (7) but there hadronic uncertainties cloud our ability to constrain the new physics [31,32]. There are contributions from the interactions of the new doublet S to the Wilson coefficient C 7 that are proportional to D U and are not suppressed bym s =m b .…”