Heavy-to-heavy quark decays at NNLO

TL;DR

This paper presents a detailed calculation of second-order QCD corrections to heavy quark decay processes, incorporating mass effects and advanced integral evaluations, with implications for both quark and muon decays.

Contribution

It introduces a novel calculation of O(alpha_s^2) corrections to b -> c decay, including c-quark mass effects and new four-loop master integrals, extending previous work.

Findings

Analytical expressions for decay corrections with mass effects.

Methodology applicable to muon decay processes.

Enhanced precision in heavy quark decay predictions.

Abstract

Details of a recent calculation of O(alpha_s^2) corrections to the decay b -> c,l,nu_l, taking into account the c-quark mass, are described. Construction of the expansion in the mass ratio m_c/m_b as well as the evaluation of new four-loop master integrals are presented. The same techniques are applicable to the muon decay, mu -> e,nu_mu,anti-nu_e. Analytical results are presented, for the physical cases as well as for a model with purely-vector couplings.