Implications of an Improved Neutron-Antineutron Oscillation Search for Baryogenesis: A Minimal Effective Theory Analysis

TL;DR

Future neutron-antineutron oscillation experiments could significantly advance our understanding of baryogenesis by probing new physics at TeV-PeV scales, beyond current collider capabilities, through an effective field theory approach.

Contribution

This paper demonstrates that upcoming $n$-$ar n$ oscillation searches can explore baryogenesis-relevant parameter space within a minimal EFT framework, linking low-energy experiments to high-energy baryon number violation.

Findings

Overlap between $n$-$ar n$ oscillation sensitivity and baryogenesis parameter space.

Exotic particle masses are in the TeV-PeV range, inaccessible at the LHC.

Future experiments can test many theories beyond current collider reach.

Abstract

Future neutron-antineutron ($n$-$\bar n$) oscillation experiments, such as at the European Spallation Source and the Deep Underground Neutrino Experiment, aim to find first evidence of baryon number violation. We investigate implications of an improved $n$-$\bar n$ oscillation search for baryogenesis via interactions of $n$-$\bar n$ mediators, parameterized by an effective field theory (EFT). We find that even in a minimal EFT setup, there is overlap between the parameter space probed by $n$-$\bar n$ oscillation and the region that can realize the observed baryon asymmetry of the universe. The mass scales of exotic new particles are in the TeV-PeV regime, inaccessible at the LHC or its envisioned upgrades. Given the innumerable high energy theories that can match to, or resemble, the minimal EFT that we discuss, future $n$-$\bar n$ oscillation experiments could probe many viable theories of baryogenesis beyond the reach of other experiments.