Asymmetries of the B→K*μ+μ− decay and the search of new physics beyond the standard model

Abstract

In this paper, we compute the forward-backward asymmetry and the isospin asymmetry of the $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ decay. The $B\ensuremath{\rightarrow}{K}^{*}$ transition form factors (TFFs) are key components of the decay. To achieve a more accurate QCD prediction, we adopt a chiral correlator for calculating the QCD light cone sum rules for those TFFs with the purpose of suppressing the uncertain high-twist distribution amplitudes. Our predictions show that the asymmetries under the standard model and the minimal supersymmetric standard model with minimal flavor violation are close in shape for ${q}^{2}\ensuremath{\ge}6\text{ }\text{ }{\mathrm{GeV}}^{2}$ and are consistent with the Belle, LHCb, and CDF data within errors. When ${q}^{2}<2\text{ }\text{ }{\mathrm{GeV}}^{2}$, their predictions behave quite differently. Thus, a careful study on the $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ decay within the small ${q}^{2}$ region could be helpful for searching new physics beyond the standard model. As a further application, we also apply the $B\ensuremath{\rightarrow}{K}^{*}$ TFFs to the branching ratio and longitudinal polarization fraction of the $B\ensuremath{\rightarrow}{K}^{*}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ decay within different models.