Thermal regularization of t-channel singularities in cosmology and particle physics: the general case
Abstract
This paper presents a~way to regularize the -channel singularity (which appears when a~massive, stable -channel mediator of a~given process is allowed to be on-shell, making the cross section infinite) in a~general case of particles of any spin (0,~\nicefrac12,~1) interacting within a~thermal medium. Those interactions result in a~finite lifetime of the mediator and allow to introduce an~effective momentum- and temperature-dependent width. As a result, the would-be-singular cross section becomes finite. A~complete derivation and an analytical result for the width are provided. For an illustration, the method is used to calculate the thermal widths and cross sections within the~Vector-Fermion Dark Matter model.
Keywords
Cite
@article{arxiv.2212.00561,
title = {Thermal regularization of t-channel singularities in cosmology and particle physics: the general case},
author = {Michal Iglicki},
journal= {arXiv preprint arXiv:2212.00561},
year = {2023}
}
Comments
v3: 31 pages, 10 figures, 9 tables; matches the revised version to appear in JHEP