Semileptonic $B_{q}\to D^{\ast}_{q}l\nu $ $(q=s, d, u)$ Decays in QCD Sum Rules

TL;DR

This paper calculates form factors for semileptonic B_q to D_q* decays using QCD sum rules, including heavy quark effective theory corrections, and compares results with models and experimental data.

Contribution

It provides a detailed QCD sum rules analysis of form factors and decay widths for B_q to D_q* semileptonic decays, including 1/m_b corrections and comparisons with other models.

Findings

Form factors are computed with QCD sum rules.

Results agree with quark meson model and experimental data.

Predictions for decay widths and ratios are provided.

Abstract

The form factors relevant to $B_{q}\to D^{\ast}_{q}(J^{P}=1^{-}) ell\nu$ $(q=s, d, u)$ decays are calculated in the framework of the three point QCD sum rules approach. The heavy quark effective theory prediction of the form factors as well as $1/m_{b}$ corrections to those form factors are obtained. A comparison of the results for the ratio of form factors at zero recoil limit and other values of $q^{2}$ with the predictions of the subleading Isgur-Wise form factor application for $B\to D^{\ast}\ell\nu$ is presented. The total decay width and branching ratio for these decays are also evaluated using the $q^2$ dependencies of these form factors. The results are in good agreement with the constituent quark meson model and existing experimental data. The $q=s$ case can also be detected at LHC in the near future.