Neutron and proton energy spectra from the non-mesonic weak decays of HeΛ5 and CΛ12

Measurement of the proton spectra from non-mesonic weak decay of 5ΛHe, 7ΛLi and 12ΛC

“…As mentioned in the Introduction, proton spectra from NMWD of 5 Λ He and 12 Λ C were already studied experimentally [2,3,6,7] and theoretically [10,13,14,22]. fig.4c, show a similar shape, i.e.…”

“…We underline the fact that we could safely use the very simple relationship (4) for the evaluation of R p thanks to the use of very thin targets and of a transparent detector. On the contrary, in previous experiments [2,3,6,7] thick targets were used to improve the statistics with the consequence that many corrections had to be applied. The results are reported in Table 1.…”

“…The subtraction of the two nucleon absorption mechanism for 6 Li cannot be done satisfactorily by using the model valid for the other nuclei. Indeed it is well known that in many reactions 6 Li behaves like an (α+d) molecule, and this cluster substructure has to be taken into account in the simulation.…”

“…Indeed it is well known that in many reactions 6 Li behaves like an (α+d) molecule, and this cluster substructure has to be taken into account in the simulation. We verified this feature in a previous work [19] and we modeled the K − (np) absorption process taking into account the momentum distribution of the deuteron inside 6 Li taken from [20] A closer inspection of the π − momentum spectrum observed for 7 Li with a proton coincidence shows a hint for a peak, centered around 269 MeV/c, i.e. 6 MeV/c below the π − peak corresponding to the 7 Λ Li formation, and labeled by the black area in the inset of Fig.2b.…”

“…However, the largest amount of data on NMWD was produced by the SKS Collaboration at KEK. The (π + ,K + ) reaction was used to produce abundantly Hypernuclei in their ground state, identified by the SKS spectrometer [4,5,6,7,8,9].…”