First determination of the one-proton induced Non-Mesonic Weak Decay width of p-shell {\Lambda}-Hypernuclei

TL;DR

This paper presents the first systematic experimental determination of the one-proton induced Non-Mesonic Weak Decay width of p-shell Lambda-Hypernuclei, using a novel method based solely on experimental data.

Contribution

It introduces a new method to extract the one-proton decay width without relying on cascade models, based on experimental spectra and linear dependence assumptions.

Findings

Gamma_2N/Gamma_p ratios are consistent with previous studies.

The new method yields decay widths in agreement with theoretical calculations.

First systematic experimental determination of this decay width.

Abstract

Previous studies of proton and neutron spectra from Non-Mesonic Weak Decay of eight Lambda-Hypernuclei (A = 5-16) have been revisited. New values of the ratio of the two-nucleon and the one-proton induced decay widths, Gamma_2N/Gamma_p, are obtained from single proton spectra, Gamma_2N/Gamma_p = 0.50 +/- 0.24, and from neutron and proton coincidence spectra, Gamma_2N/Gamma_p = 0.36 +/- 0.14stat +0.05sys -0.04sys , in full agreement with previously published ones. With these values, a method is developed to extract the one-proton induced decay width in units of the free Lambda decay width, Gamma_p/Gamma_Lambda, without resorting to Intra Nuclear Cascade models but by exploiting only experimental data, under the assumption of a linear dependence on A of the Final State Interaction contribution. This is the first systematic determination ever done and it agrees within the errors with recent theoretical calculations.