Nonmesonic Weak Decay Spectra and Three-Nucleon Emission

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.