2025/11/03 by J. Barrow, Barrow, Joshua L., P. Fierlinger +11 · 1 citation
Physics and Astronomy · #Nuclear physics research studies #Quantum Chromodynamics and Particle Interactions #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.2511.01829
Experimental searches for neutron--antineutron (n → n) transitions can be considered via two approaches: conversion in free-neutron beams and intranuclear transformation leading to matter instability in large-mass detectors. Plans for next-generation searches make it timely to highlight the complementarity, necessity, and limitations of each method. Converting the bound neutron limit into one for free neutrons traditionally utilizes nucleus-specific estimates of the in-medium suppression of n → n, obtained within mean-field theory under a single-operator assumption. This paper highlights how this suppression can be scenario-dependent, which can lead to deviations from the standard approach that can span several orders of magnitude. A further goal of the paper is to point out the need for a broader phenomenology program for n→ n that is akin to those developed for electric dipole moments and other systems for which short-distance new physics must be studied in-medium.