Physics Letters B (Nov 2014)

First determination of the one-proton induced Non-Mesonic Weak Decay width of p-shell Λ-Hypernuclei

  • M. Agnello,
  • L. Benussi,
  • M. Bertani,
  • H.C. Bhang,
  • G. Bonomi,
  • E. Botta,
  • T. Bressani,
  • S. Bufalino,
  • D. Calvo,
  • P. Camerini,
  • B. Dalena,
  • F. De Mori,
  • G. D'Erasmo,
  • A. Feliciello,
  • A. Filippi,
  • H. Fujioka,
  • P. Gianotti,
  • N. Grion,
  • V. Lucherini,
  • S. Marcello,
  • T. Nagae,
  • H. Outa,
  • V. Paticchio,
  • S. Piano,
  • R. Rui,
  • G. Simonetti,
  • A. Zenoni

Journal volume & issue
Vol. 738
pp. 499 – 504

Abstract

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Previous studies of proton and neutron spectra from Non-Mesonic Weak Decay of eight Λ-Hypernuclei (A=5–16) have been revisited. New values of the ratio of the two-nucleon and the one-proton induced decay widths, Γ2N/Γp, are obtained from single proton spectra, Γ2N/Γp=0.50±0.24, and from neutron and proton coincidence spectra, Γ2N/Γp=0.36±0.14stat−0.04sys+0.05sys, 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 Λ decay width, Γp/ΓΛ, 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. Keywords: Λ-Hypernuclei, Two-nucleon and proton-induced Non-Mesonic Weak Decay width