Standard Model light-by-light scattering in SANC: analytic and numeric evaluation

TL;DR

This paper details the implementation and numerical evaluation of the Standard Model light-by-light scattering process in the SANC system, including massive loop particles and comparison with existing results.

Contribution

It introduces a comprehensive implementation of the $ o$ process in SANC, accounting for particle masses and providing analytic and numeric results.

Findings

Covariant and helicity amplitudes derived

Numerical results consistent with literature

Precomputation modules for massive diagrams included

Abstract

In this paper we describe the implementation of the SM process $\gamma\gamma\to\gamma\gamma$ through a fermion and boson loops into the framework of SANC system. The computations of this process takes into account non-zero mass of loop particles. We briefly describe additional precomputation modules used for calculation of massive box diagrams. We present the covariant and helicity amplitudes for this process, some particular cases of $D_0$ and $C_0$ Passarino--Veltman functions and also numerical results of corresponding SANC module evaluation. Whenever possible, we compare the results with those existing in the literature.