News on PHOTOS Monte Carlo: gamma^* -> pi^+ pi^-(gamma) and K^\pm -> pi^+ pi^- e^\pm nu (gamma)

TL;DR

This paper discusses updates to the PHOTOS Monte Carlo tool for simulating QED effects in specific particle decay processes, emphasizing its relevance for precision measurements and theoretical calculations.

Contribution

It introduces the simulation of gamma^* -> pi^+ pi^-(gamma) and K^\pm -> pi^+ pi^- e^\pm nu (gamma) decays within Scalar QED in PHOTOS, enhancing its accuracy for key physics applications.

Findings

Improved simulation accuracy for gamma^* decays involving pions.

Enhanced modeling of K^\pm decays with radiative effects.

Relevance for precision measurements of alpha_{QED}(M_Z) and g-2.

Abstract

PHOTOS Monte Carlo is widely used for simulating QED effects in decay of intermediate particles and resonances. It can be easily connected to other main process generators. In this paper we consider decaying processes gamma^* -> pi^+ pi^-(gamma) and K^\pm -> pi^+ pi^- e^\pm nu (gamma) in the framework of Scalar QED. These two processes are interesting not only for the technical aspect of PHOTOS Monte Carlo, but also for precision measurement of alpha_{QED}(M_Z), g-2, as well as pi pi scattering lengths.