English

B->V gamma Beyond QCD Factorisation

High Energy Physics - Phenomenology 2008-11-26 v3

Abstract

We calculate the main observables in Bu,d(ρ,ω,K)γB_{u,d}\to (\rho,\omega,K^*)\gamma and Bs(Kˉ,ϕ)γB_s\to (\bar K^*,\phi)\gamma decays, i.e. branching ratios and CP and isospin asymmetries. We include QCD factorisation results and also the dominant contributions beyond QCD factorisation, namely long-distance 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 BB factories, the LHC and a future super-flavour factory. Using current experimental data, we also extract Vtd/Vts|V_{td}/V_{ts}| and the angle γ\gamma 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.

Keywords

Cite

@article{arxiv.hep-ph/0612081,
  title  = {B->V gamma Beyond QCD Factorisation},
  author = {Patricia Ball and Gareth W. Jones and Roman Zwicky},
  journal= {arXiv preprint arXiv:hep-ph/0612081},
  year   = {2008}
}

Comments

49 pages, version to appear in PRD