Master Integrals for double real radiation emission in heavy-to-light quark decay

TL;DR

This paper analytically computes master integrals for double real radiation emission in the b to u W* decay, advancing the precision of NNLO QCD calculations for semileptonic B meson decays.

Contribution

It provides the first complete analytic evaluation of master integrals for this process, facilitating fully analytic NNLO predictions for semileptonic B decays.

Findings

Results expressed in terms of multiple polylogarithms of weight four.

Progress toward a fully analytic NNLO computation of differential distributions.

Enhances understanding of inclusive semileptonic charmless B decays.

Abstract

We evaluate analytically the master integrals for double real radiation emission in the b --> u W* decay, where b and u are a massive and massless quark, respectively, while W* is an off-shell charged weak boson. Since the W boson can subsequently decay in a lepton anti-neutrino pair, the results of the present paper constitute a further step toward a fully analytic computation of differential distributions for the semileptonic decay of a b quark at NNLO in QCD. The latter partonic process plays a crucial role in the study of inclusive semileptonic charmless decays of B mesons. Our results are expressed in terms of multiple polylogarithms of maximum weight four.