Factorization effects in a model of unstable particles

TL;DR

This paper demonstrates that in a model of unstable particles with smeared mass, two-particle cross sections and three-particle decay widths can be universally factorized, simplifying calculations for complex scattering and decay processes.

Contribution

It introduces a universal factorization formula for unstable particles of any spin within the smeared mass model, extending to complex processes.

Findings

Exact factorization due to propagator structure

Applicability of the method to complex processes

Evaluation of the method's accuracy

Abstract

The effects of factorization are considered within the framework of the model of unstable particles with a smeared mass. It is shown that two-particle cross section and three-particle decay width can be described by the universal factorized formulae for an unstable particles of an arbitrary spin in an intermediate state. The exact factorization is caused by the specific structure of the model unstable-particle propagators. This result is generalized to complicated scattering and decay-chain processes with unstable particles in intermediate states. We analyze applicability of the method and evaluate its accuracy.