Limiting Equivalence Principle Violation and Long-Range Baryonic Force from Neutron-Antineutron Oscillation

TL;DR

Discovering neutron-antineutron oscillation would tightly constrain violations of Einstein's equivalence principle and limit the strength of hypothetical long-range baryonic forces, surpassing existing bounds.

Contribution

This paper establishes new, extremely stringent limits on long-range baryonic forces based on potential neutron-antineutron oscillation observations.

Findings

Limits on baryonic force strength $oldsymbol{eta_B extless{} 2 imes 10^{-57}}$ for ranges over a megaparsec.

Strong constraints on equivalence principle violation at the level of one part in $oldsymbol{10^{19}}$.

Potential bounds from Earth and Sun considered for shorter-range forces.

Abstract

We point out that if the baryon number violating neutron-antineutron oscillation is discovered, it would impose strong limits on the departure from Einstein's equivalence principle at a level of one part in $10^{19}$. If this departure owes its origin to the existence of long-range forces coupled to baryon number $B$ (or $B-L$), it would imply very stringent constraints on the strength of gauge bosons coupling to baryon number current. For instance, if the force mediating baryon number has strength $\alpha_B$ and its range is larger than a megaparsec, we find the limit to be $\alpha_B \leq 2\times 10^{-57}$, which is much stronger than all other existing bounds. For smaller range for the force, we get slightly weaker, but still stringent bounds by considering the potential of the Earth and the Sun.