Weak Interactions Effect on the P-N Mass Splitting and the Principle of Equivalence

TL;DR

This paper calculates the weak interaction's role in proton-neutron mass difference and shows its impact on the equivalence principle tests, tightening constraints on possible violations.

Contribution

It introduces a generalized Cottingham's formula to compute weak interaction effects on mass differences and refines bounds on equivalence principle violations.

Findings

Weak interactions contribute significantly to P-N mass splitting.

Including this effect tightens bounds on equivalence principle violations.

The analysis reduces the allowed violation by an order of magnitude.

Abstract

The weak interaction contribution to the proton neutron mass difference is computed using a generalization of Cottingham's formula. When included in the analysis of the Eotvos experiment, this contribution reduces the bound on a possible weak interactions violation to the equivalence principle by one order of magnitude.