Kinetic corrections to B -> X_c l nu at one loop

TL;DR

This paper calculates one-loop quantum corrections to the kinetic operator in B meson decays, refining theoretical predictions crucial for precise determination of fundamental parameters like |V_cb| and quark masses.

Contribution

It provides the first evaluation of one-loop corrections to the Wilson coefficient of the kinetic operator in B decay, enhancing the accuracy of theoretical models.

Findings

One-loop corrections modify spectral moments by about 20%.

Corrections are small for most moments but significant for those vanishing at lowest order.

Results support high-precision extraction of |V_cb| and quark masses.

Abstract

We evaluate the one-loop corrections to the Wilson coefficient of the kinetic operator in the operator product expansion of the differential B -> X_c l nu decay rate. With a moderate cut on the lepton energy, the one-loop terms change the kinetic operator contributions to spectral moments by about 20%. This amounts to a small correction for leptonic and hadronic moments, except for those which vanish at the lowest order, where the effect can be sizable. Together with a two-loop calculation of the leading-power rate and an evaluation of the one-loop corrections to the Wilson coefficient of the chromo-magnetic operator, our results will allow for a high-precision determination of |V_cb| and the b- and c-quark masses.