Ionization of hydrogen by neutrino magnetic moment, relativistic muon, and WIMP

TL;DR

This paper analyzes hydrogen ionization caused by neutrino magnetic moments, relativistic muons, and WIMPs, providing analytic results and evaluating approximation schemes relevant for low-threshold dark matter and neutrino detection experiments.

Contribution

It offers the first analytic comparison of ionization cross sections for these particles and assesses the validity of common approximation methods in atomic physics.

Findings

Analytic expressions for ionization cross sections were derived.

Approximation schemes' applicability was evaluated for low-energy regimes.

Results inform detector design for neutrino and dark matter searches.

Abstract

We studied the ionization of hydrogen by scattering of neutrino magnetic moment, relativistic muon, and weakly-interacting massive particle with a QED-like interaction. Analytic results were obtained and compared with several approximation schemes often used in atomic physics. As current searches for neutrino magnetic moment and dark matter have lowered the detector threshold down to the sub-keV regime, we tried to deduce from this simple case study the influence of atomic structure on the the cross sections and the applicabilities of various approximations. The general features being found will be useful for cases where practical detector atoms are considered.