Nonmesonic Weak Decay Spectra and Three-Nucleon Emission

TL;DR

This paper evaluates nonmesonic weak decay spectra in hypernuclei using a shell-model approach and compares them with recent experimental data, questioning the reliability of extracting three-body decay rates from these measurements.

Contribution

It provides a theoretical analysis of decay spectra and critically assesses the methods used to extract three-nucleon induced decay rates from experimental data.

Findings

Comparison shows discrepancies between theory and experiment.

Questioning the validity of current data analysis methods.

Highlights the need for improved extraction techniques.

Abstract

We have evaluated the nonmesonic weak decay spectra within the independent-particle shell-model, and compared them with the recent measurements of: i) the single and double coincidence nucleon spectra in ${\mathrm{^{12}_{\Lambda}C}}$ performed at KEK, and ii) proton kinetic energy spectra in ${\mathrm{^{5}_{\Lambda}He}}$, ${\mathrm{^{7}_{\Lambda}Li}}$, ${\mathrm{^{9}_{\Lambda}Be}}$, ${\mathrm{^{11}_{\Lambda}B}}$, ${\mathrm{^{12}_{\Lambda}C}}$, ${\mathrm{^{13}_{\Lambda}C}}$, ${\mathrm{^{15}_{\Lambda}N}}$ and ${\mathrm{^{16}_{\Lambda}O}}$ done by FINUDA. Based on this comparison we argue that the extraction from the data of the three-body $\Lambda NN \rightarrow nNN$ induced decay rate, as done in these works, could be questionable.