New-physics contributions to the forward-backward asymmetry in B -> K* mu+ mu-

ASHUTOSH KUMAR ALOK; AMOL DIGHE; DIPTIMOY GHOSH; DAVID LONDON; JOAQUIM MATIAS; MAKIKO NAGASHIMA; ALEJANDRO SZYNKMAN

JOURNAL OF HIGH ENERGY PHYSICS - (Online)

SPRINGER

Año: 2010 vol. 1002 p. 53 - 84

1029-8479

We study the forward-backward asymmetry (AFB) and the differentialbranching ratio (DBR) in B -> K* mu+ mu- in the presence of new physics (NP) withdifferent Lorentz structures. We consider NP contributions from vector-axial vector(VA), scalar-pseudoscalar (SP), and tensor (T) operators, as well as their combina-tions. We calculate the effects of these new Lorentz structures in the low-q2 andhigh-q2 regions, and explain their features through analytic approximations. We findtwo mechanisms that can give a significant deviation from the standard-model pre-dictions, in the direction indicated by the recent measurement of AFB by the Belleexperiment. They involve the addition of the following NP operators: (i) VA, or (ii)a combination of SP and T (slightly better than T alone). These two mechanismscan be distinguished through measurements of DBR in B -> K* mu+ mu- and AFB inB -> K mu+ mu-.