Improved constraints on exotic interactions between electron and proton in hydrogen

TL;DR

This paper uses precise atomic hydrogen hyperfine splitting measurements to set new limits on hypothetical exotic bosons mediating forces between electrons and protons, improving constraints on their coupling strengths.

Contribution

It provides the most stringent bounds to date on electron-proton exotic interactions via atomic spectroscopy comparisons.

Findings

Improved constraints on axial-vector, pseudoscalar, and vector boson couplings.

Utilizes recent high-precision measurements and quantum electrodynamics theory.

Enhances the search for new physics beyond the Standard Model.

Abstract

Atomic spectroscopy can be used to search for new bosons that carry exotic forces between elementary fermions. A comparison of a recent precise measurement [Bullis \textit{et al.}, Phys. Rev. Lett. \textbf{130}, 203001 (2023)] of the hyperfine splitting of the 2S$_{1/2}$ electronic levels of hydrogen and up-to-date bound-state quantum electrodynamics theory yields improved constraints on electron-proton exotic interactions of the dimensionless coupling strengths $g_Ag_A$, $g_pg_p$, and $g_Vg_V$ corresponding to the exchange of a axial-vector, pseudoscalar (axionlike) or vector boson, respectively.