An Analytical Method for the NLO QCD Corrections to Double-Higgs Production

TL;DR

This paper introduces a new analytical method for calculating higher-order QCD corrections to Higgs pair production, providing accurate approximations in the energy region where most of the cross section occurs.

Contribution

The paper presents a novel expansion-based analytical approach for two-loop virtual corrections in Higgs pair production, improving upon heavy mass expansion methods.

Findings

Achieves better than per-mille accuracy in the relevant energy region.

Applicable to other 2→2 processes with virtual higher-order corrections.

Provides a general, straightforward computational framework.

Abstract

We propose a new method to calculate analytically higher-order perturbative corrections and we apply it to the calculation of the two-loop virtual corrections to Higgs pair production through gluon fusion. The method is based on the expansion of the amplitudes in terms of a small Higgs transverse momentum. This approach gives a very good approximation (better than per-mille) of the partonic cross section in the center of mass energy region $\sqrt{\hat{s}} \lesssim 750$ GeV, where $\sim95\%$ of the total hadronic cross section is concentrated. The presented method is general and can be applied in a straightforward way to the computation of virtual higher-order corrections to other $2\to2$ processes, representing an improvement with respect to calculations based on heavy mass expansions.