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 neu- tron, has triggered the investigation of the two-nucleon induced ΛN N → nN N decay channel: its weight has been evaluated to be Γ2 /ΓN M = 0.21 ± 0.07stat +0.03 sys . Finally, a direct experimental evidence of the −0.02 sys 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 7ΛLi and 9ΛBe two-nucleon induced non-mesonic weak decay; the kinematical analysis is discussed here.
Hypernuclear weak decay studies with FINUDA
BOTTA, Elena;BRESSANI, Tullio;BUSSO, Luigi;DE MORI, FRANCESCA;MARCELLO, Simonetta;
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 neu- tron, has triggered the investigation of the two-nucleon induced ΛN N → nN N decay channel: its weight has been evaluated to be Γ2 /ΓN M = 0.21 ± 0.07stat +0.03 sys . Finally, a direct experimental evidence of the −0.02 sys 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 7ΛLi and 9ΛBe two-nucleon induced non-mesonic weak decay; the kinematical analysis is discussed here.File | Dimensione | Formato | |
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