The FINUDA experiment has recently completed an extensive study of the weak decay of p-shell Λ- hypernuclei including both mesonic and non-mesonic modes. Charged mesonic decay rates have been determined based on the analysis of π − kinetic energy spectra, never measured before. The study of proton spectra from non-mesonic weak decay for p-shell hypernuclei, both single and in coincidence with a neutron, has triggered the investigation of the two-nucleon induced ΛNN →nNN decay channel: its weight has been evaluated to be Γ2/ΓNM = 0.21±0.07stat +0.03 sys −0.02 sys. Finally, a direct experimental evidence of the occurrence of the weak reaction Λnp →nnp in nuclei is presented for the first time. Three events have been found which can be attributed to 7 ΛLi and 9 ΛBe two-nucleon induced non-mesonic weak decay; the kinematical analysis is discussed here.
Hypernuclear weak decay studies with FINUDA / M., A., L., B., M., B., H. C., B., G., B., E., B., Bregant, M., T., B., S., B., L., B., D., C., Camerini, P., B., D., F., D.M., G., D., F. L., F., A., F., A., F., E. M., F., H., F., et al.. - In: NUCLEAR PHYSICS. A. - ISSN 0375-9474. - STAMPA. - 881:(2012), pp. 322-338. [10.1016/j.nuclphysa.2012.01.024]
Hypernuclear weak decay studies with FINUDA
BREGANT, MARCO;CAMERINI, Paolo;PIANO, STEFANO;RUI, RINALDO;
2012-01-01
Abstract
The FINUDA experiment has recently completed an extensive study of the weak decay of p-shell Λ- hypernuclei including both mesonic and non-mesonic modes. Charged mesonic decay rates have been determined based on the analysis of π − kinetic energy spectra, never measured before. The study of proton spectra from non-mesonic weak decay for p-shell hypernuclei, both single and in coincidence with a neutron, has triggered the investigation of the two-nucleon induced ΛNN →nNN decay channel: its weight has been evaluated to be Γ2/ΓNM = 0.21±0.07stat +0.03 sys −0.02 sys. Finally, a direct experimental evidence of the occurrence of the weak reaction Λnp →nnp in nuclei is presented for the first time. Three events have been found which can be attributed to 7 ΛLi and 9 ΛBe two-nucleon induced non-mesonic weak decay; the kinematical analysis is discussed here.Pubblicazioni consigliate
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