Impact of a Reflecting Material on a Search for Neutron--Antineutron Oscillations using Ultracold Neutrons

TL;DR

This paper explores how a reflecting material affects the sensitivity of ultracold neutron experiments searching for neutron--antineutron oscillations, focusing on optimizing the antineutron pseudopotential to improve detection prospects.

Contribution

It introduces a theoretical framework for understanding the impact of wall reflectivity and phase shifts on experimental sensitivity, proposing methods to determine the antineutron pseudopotential.

Findings

Sensitivity depends on antineutron reflectivity and phase shift.

Optimizing the antineutron pseudopotential enhances experimental sensitivity.

Methods for directly determining the pseudopotential are discussed.

Abstract

We investigate neutron--antineutron oscillations of ultracold neutrons in a storage bottle represented by a one-dimensional potential. The experimental sensitivity is determined by the annihilation rate of antineutrons. Its dependence on the antineutron reflectivity and the relative phase shift between the neutron and the antineutron wavefunctions by a reflection from the wall is derived. Optimization of the antineutron pseudopotential was found crucial to maximize the sensitivity of the experiment. Furthermore, methods are discussed for determining the antineutron pseudopotential, which has only been studied indirectly thus far.