Constraints on exotic spin-dependent interactions between matter and antimatter from antiprotonic helium spectroscopy

TL;DR

This study uses precise spectroscopy of antiprotonic helium to set new constraints on hypothetical spin-dependent forces between matter and antimatter, exploring potential new physics beyond the standard model.

Contribution

First experimental search for semileptonic spin-dependent interactions between matter and antimatter using antiprotonic helium spectroscopy.

Findings

Established new limits on exotic spin-dependent interactions.

Demonstrated the sensitivity of antiprotonic helium spectroscopy for probing new physics.

Provided constraints on spin- and velocity-dependent forces involving electrons and antiprotons.

Abstract

Heretofore undiscovered spin-0 or spin-1 bosons can mediate exotic spin-dependent interactions between standard-model particles. Here we carry out the first search for semileptonic spin-dependent interactions between matter and antimatter. We compare theoretical calculations and spectroscopic measurements of the hyperfine structure of antiprotonic helium to constrain exotic spin- and velocity-dependent interactions between electrons and antiprotons.