Higgs boson decay into b-quarks at NNLO accuracy

TL;DR

This paper presents a precise calculation of the Higgs boson decay into b-quarks at NNLO accuracy, using a novel subtraction scheme to handle infrared divergences in QCD corrections.

Contribution

It introduces a universal subtraction scheme for NNLO QCD calculations applied to Higgs decay, enabling accurate differential decay rate predictions.

Findings

Successfully computed differential decay rates at NNLO

Validated the subtraction scheme with infrared pole cancellation

Demonstrated the method's applicability to physical observables

Abstract

We compute the fully differential decay rate of the Standard Model Higgs boson into b-quarks at next-to-next-to-leading order (NNLO) accuracy in alpha_S. We employ a general subtraction scheme developed for the calculation of higher order perturbative corrections to QCD jet cross sections, which is based on the universal infrared factorization properties of QCD squared matrix elements. We show that the subtractions render the various contributions to the NNLO correction finite. In particular, we demonstrate analytically that the sum of integrated subtraction terms correctly reproduces the infrared poles of the two-loop double virtual contribution to this process. We present illustrative differential distributions obtained by implementing the method in a parton level Monte Carlo program. The basic ingredients of our subtraction scheme, used here for the first time to compute a physical observable, are universal and can be employed for the computation of more involved processes.