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Title: B{yields}V{gamma} beyond QCD factorization

Abstract

We calculate the main observables in B{sub u,d}{yields}({rho},{omega},K*){gamma} and B{sub s}{yields}(K*,{phi}){gamma} decays, i.e. branching ratios and CP and isospin asymmetries. We include QCD factorization results and also the dominant contributions beyond QCD factorization, namely, long-distance photon emission and soft-gluon emission from quark loops. All contributions beyond QCD factorization 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 nonleptonic decays. Our results are relevant for new-physics searches at the B factories, CERN LHC and a future superflavor factory. Using current experimental data, we also extract |V{sub td}/V{sub ts}| and the angle {gamma} of the unitarity triangle. We give detailed tables of theoretical uncertainties of the relevant quantities which facilitates future determinations of these Cabibbo-Kobayashi-Maskawa parameters from updated experimental results.

Authors:
; ;  [1]
  1. IPPP, Department of Physics, University of Durham, Durham DH1 3LE (United Kingdom)
Publication Date:
OSTI Identifier:
21020051
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevD.75.054004; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; B MESONS; BRANCHING RATIO; CERN LHC; CP INVARIANCE; FACTORIZATION; GAMMA DECAY; GLUONS; ISOSPIN; K*-892 MESONS; KOBAYASHI-MASKAWA MATRIX; LIGHT CONE; OMEGA-782 MESONS; PHOTON EMISSION; QUANTUM CHROMODYNAMICS; QUARKS; RHO-770 MESONS; SUM RULES; UNITARITY; WEAK HADRONIC DECAY

Citation Formats

Ball, Patricia, Jones, Gareth W., and Zwicky, Roman. B{yields}V{gamma} beyond QCD factorization. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.054004.
Ball, Patricia, Jones, Gareth W., & Zwicky, Roman. B{yields}V{gamma} beyond QCD factorization. United States. doi:10.1103/PHYSREVD.75.054004.
Ball, Patricia, Jones, Gareth W., and Zwicky, Roman. Thu . "B{yields}V{gamma} beyond QCD factorization". United States. doi:10.1103/PHYSREVD.75.054004.
@article{osti_21020051,
title = {B{yields}V{gamma} beyond QCD factorization},
author = {Ball, Patricia and Jones, Gareth W. and Zwicky, Roman},
abstractNote = {We calculate the main observables in B{sub u,d}{yields}({rho},{omega},K*){gamma} and B{sub s}{yields}(K*,{phi}){gamma} decays, i.e. branching ratios and CP and isospin asymmetries. We include QCD factorization results and also the dominant contributions beyond QCD factorization, namely, long-distance photon emission and soft-gluon emission from quark loops. All contributions beyond QCD factorization 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 nonleptonic decays. Our results are relevant for new-physics searches at the B factories, CERN LHC and a future superflavor factory. Using current experimental data, we also extract |V{sub td}/V{sub ts}| and the angle {gamma} of the unitarity triangle. We give detailed tables of theoretical uncertainties of the relevant quantities which facilitates future determinations of these Cabibbo-Kobayashi-Maskawa parameters from updated experimental results.},
doi = {10.1103/PHYSREVD.75.054004},
journal = {Physical Review. D, Particles Fields},
number = 5,
volume = 75,
place = {United States},
year = {Thu Mar 01 00:00:00 EST 2007},
month = {Thu Mar 01 00:00:00 EST 2007}
}
  • The factorization properties of the radiative decays B{yields}V{gamma} are analyzed at leading order in 1/m{sub b} using the soft-collinear effective theory. It is shown that the decay amplitudes can be expressed in terms of a B{yields}V form factor evaluated at q{sup 2}=0, light-cone distribution amplitudes of the B and V mesons, and calculable hard-scattering kernels. The renormalization-group equations in the effective theory are solved to resum perturbative logarithms of the different scales in the decay process. Phenomenological implications for the B{yields}K*{gamma} branching ratio, isospin asymmetry, and CP asymmetries are discussed, with particular emphasis on possible effects from physics beyond themore » standard model.« less
  • A careful investigation of 1/m{sub b} power-suppressed effects is crucial for enhancing predictive power of the QCD factorization approach to charmless B decays. It is instructive to systematically investigate the 1/m{sub b} effects from soft- and hard-gluon exchanges, in addition to annihilation topology in the charmless B decays. In this work we try to give a systematic discussion on impact of such soft and hard exchanges on the penguin-dominated B{yields}K{pi} decays within the framework of the light-cone QCD sum rules (LCSR). For the weak phase {gamma}(=ImV{sub ub}*) ranging from 40 deg. to 80 deg. , we find that because ofmore » the annihilation and soft and hard exchanges a numerical increase of 20-30% is expected in the branching ratios up to O(1/m{sub b}{sup 2}) corrections; the resultant soft and hard corrections are less important than the annihilation contributions and amount only to a level of 10%. Possible sources of uncertainties are discussed in some details.« less
  • The B{sub c}{yields}B{sub q}{sup (*)}P, B{sub q}V decays are studied with the QCD factorization approach (where P and V denote pseudoscalar and vector mesons, respectively; q=u, d, and s). Considering the contributions of both current-current and penguin operators, the amplitudes of branching ratios are estimated at the leading approximation. We find that the contributions of the penguin operators are very small due to the serious suppression by the Cabibbo-Kobayashi-Maskawa elements. The most promising decay modes are B{sub c}{yields}B{sub s}{sup (*)}{pi}, B{sub s}{rho}, which might be easily detected at hadron colliders.
  • We prove the factorization theorem for the processes {pi}{gamma}{sup *}{r_arrow}{gamma} and {pi}{gamma}{sup *}{r_arrow}{pi} to leading twist in the covariant gauge by means of the Ward identity. Soft divergences cancel and collinear divergences are grouped into a pion wave function defined by a nonlocal matrix element. The gauge invariance and universality of the pion wave function are confirmed. The proof is then extended to the exclusive B meson decays B{r_arrow}{gamma}l{bar {nu}} and B{r_arrow}{pi}l{bar {nu}} in the heavy quark limit. It is shown that a light-cone B meson wave function, though absorbing soft dynamics, can be defined in an appropriate frame. Factorizationmore » of the B{r_arrow}{pi}l{bar {nu}} decay in k{sub T} space, k{sub T} being parton transverse momenta, is briefly discussed. We comment on the extraction of the leading-twist pion wave function from experimental data.« less
  • No abstract prepared.