Neutron disappearance inside the nucleus

TL;DR

This paper investigates the potential for neutrons to disappear inside nuclei via baryon-violating interactions, which could impact neutron decay lifetime measurements and suggest new decay channels involving dark matter particles.

Contribution

It provides calculations of neutron disappearance widths within nuclei, exploring implications for baryon violation and dark matter emission, a novel approach in this context.

Findings

Discovered that neutron disappearance width in $^{11}$Be exceeds beta decay width.

Identified severe constraints on neutron decay into dark matter and gamma emission.

Indicated potential for baryon violation signals in nuclear decay processes.

Abstract

We consider the possibility that a neutron may disappear inside the nucleus, which will demonstrate the existence of baryon violating $\Delta B=1$ interactions. It has recently been proposed that such a process may have an effect on the free neutron decay life time. We evaluate the widths for $n\rightarrow \chi$ and $n\rightarrow \chi \gamma$, with $\chi$ being a light dark matter particle emitted by a loosely bound neutron in various light nuclei. We find that, assuming a mass $m_{\chi}$ close to 938 MeV, the obtained width for $n\rightarrow \chi$ in $^{11}$Be is much larger than the corresponding beta decay width. This suggests a severe limit on the possible decay channel of $n \rightarrow \chi \gamma $ for free neutron.