# Master integrals for two-loop $C$-odd contribution to $e^+e^-\to \ell^+\ell^-$ process

## TL;DR

This paper computes two-loop master integrals for the $C$-odd contribution to $e^+e^- o ext{leptons}$, enabling precise theoretical predictions for heavy lepton pair production in electron-positron collisions.

## Contribution

It provides the first calculation of two-loop master integrals for the $C$-odd diagrams with three photons, in the zero electron mass limit, relevant for the entire physical region.

## Key findings

- Explicit expressions for the master integrals are obtained.
- Results are applicable to the entire physical region of the process.
- The calculations facilitate higher-precision theoretical predictions.

## Abstract

We calculate two-loop master integrals for the process of heavy lepton pair production in $e^+e^-$ collisions. We consider the $C$-odd diagrams with three photons in the intermediate state and evaluate the corresponding families of the master integrals in the limit of zero electron mass. Our results for the master integrals are directly applicable in the whole physical region corresponding to the annihilation channel.