The B -> K* transition form factors within the QCD light-cone sum rules and their application to the semi-leptonic decay B -> K* mu(+)mu(-)

摘要

We present a detailed calculation on the B -> K* transition form factors (TFFs), A(0,1,2), V and T-1,T-2,T-3, within the QCD light-cone sum rules (LCSRs). To suppress the contributions from high-twist light-cone distribution amplitudes, we adopt a right-handed chiral correlator to do the LCSR calculation. In the resultant LCSRs for the TFFs, the transverse leading-twist distribution amplitude phi(perpendicular to)(2;K) provides over 90% contribution, thus those TFFs provide good platforms for testing the property of phi(perpendicular to)(2;K*), We suggest a model for phi(perpendicular to)(2;K*), in which two parameters B-2;K*(perpendicular to) and C-2;K*(perpendicular to) dominantly control its longitudinal distribution. With a proper choice of B-2;K*(perpendicular to), and our predictions on B -> K* TFFs are consistent with those of lattice QCD predictions. As an application, we also calculate the branching fraction of the B-meson rare decay B -> K*mu(+)mu(-). The predicted differential branching fraction, dB/dq(2)(B -> K* mu(+)mu(-)) is consistent with the LHCb and Belle measurements within errors. After integrating over the allowable q(2)-region, we get the branching fraction, B(B -> K*mu(+)mu(-)) = (1.088(-0.205)(+0.261)) x 10(-6), where the errors are squared average of the mentioned error sources. When the precision of experimental measurements or the other source of theoretical uncertainties for this process have been further improved in the future, we may get a definite conclusion on the behavior of phi(perpendicular to)(2;K*).