On threshold amplitudes III: 2 into n processes

TL;DR

This paper investigates 2 into n scattering processes with stationary final particles, identifying symmetries that cause certain amplitudes to vanish by comparing with soft processes, and provides illustrative examples.

Contribution

It introduces a symmetry-based analysis of 2 into n scattering amplitudes and clarifies conditions for their vanishing, extending previous theoretical frameworks.

Findings

Identified symmetries responsible for vanishing amplitudes.

Compared 2 into n processes with soft processes.

Provided explicit examples illustrating the phenomena.

Abstract

The 2 into n scattering with final particles at rest is discussed. The comparison with purely soft processes allows to identify symmetries responsible for vanishing of certain 2 into n amplitudes. Some examples are given.