Pseudovector and pseudoscalar spin-dependent interactions in atoms

TL;DR

This paper explores atomic spectroscopy as a method to detect hypothetical pseudovector and pseudoscalar particles through their unique spin-dependent interactions, setting experimental limits on their interaction strengths.

Contribution

It introduces a theoretical framework for potential interactions from pseudovector and pseudoscalar particles and derives experimental constraints from atomic spectra data.

Findings

Limits on pseudovector interaction constants derived from atomic spectra.

Limits on pseudoscalar interaction constants from atomic spectroscopy.

Potential for atomic spectroscopy to detect or constrain new elementary particles.

Abstract

Hitherto unknown elementary particles can be searched for with atomic spectroscopy. We conduct such a search using a potential that results from the longitudinal polarization of a pseudovector particle. We show that such a potential, inversely proportional to the boson's mass squared, $V \propto 1/M^2$, can stay finite at $M \to 0$ if the theory is renormalizable. We also look for a pseudoscalar boson, which induces a contact spin-dependent potential that does not contribute to new forces searched for in experiments with macroscopic objects, but may be seen in atomic spectroscopy. We extract limits on the interaction constants of these potentials from the experimental spectra of antiprotonic helium, muonium, positronium, helium, and hydrogen.