QCD corrections at subleading power for inclusive nonleptonic $b\rightarrow c\bar u d$ decays

TL;DR

This paper calculates next-to-leading order QCD corrections for inclusive nonleptonic B-hadron decays at subleading power, reducing theoretical uncertainties and stabilizing key coefficients, which slightly increases decay rate predictions.

Contribution

It provides the first NLO QCD correction calculation for the chromomagnetic moment coefficient at subleading power in B-hadron decays, improving theoretical precision.

Findings

Renormalization-scale dependence is significantly reduced.

The sign of the chromomagnetic coefficient becomes stable.

Decay rates are estimated to increase by around 2% at NLO.

Abstract

In this paper we compute the NLO QCD corrections for the inclusive nonleptonic decay rates of $B$-hadrons at subleading power of the heavy quark expansion. In particular, we discuss the coefficient of the chromomagnetic moment parameter $\mu_G$ which has a large uncertainty at leading order due to its dependence on the renormalization scale. We find that the renormalization-scale dependence of this coefficient is significantly reduced, thereby reducing the theoretical uncertainty of the coefficient and consequently of the rates. The sign of the coefficient becomes stable, and we estimate that the NLO corrections will increase the decay rates by around $2\%$.