IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Nonmesonic weak decay of Λ hypernuclei: The Λ N − Σ N coupling
Autor/es:
BAUER, E.; GARBARINO, G.; RODRÍGUEZ PEÑA, C. A.
Revista:
Physical Review C
Editorial:
APS
Referencias:
Año: 2017 vol. 96 p. 1 - 14
ISSN:
2469-9985
Resumen:
The nonmesonic weak decay of $Lambda$ hypernuclei is studied within a microscopicdiagrammatic approach which is extended to include the $Lambda N$--$Sigma N$ stronginteraction coupling. We adopt a nuclear matter formalism which, through the local densityapproximation, allows us to model finite hypernuclei. One--meson--exchange potentialsare used for the weak and strong four--baryon interactions.The rates for the neutron-- and proton--induced weak decays,$Lambda N o nN$ and $Lambda No Sigma No nN$ ($N=n$ or $p$, $Sigma=Sigma^-$, $Sigma^0$ and $Sigma^+$),are predicted for $^{12}_Lambda$C, $^{28}_Lambda$Si, $^{56}_Lambda$Fe and$^{208}_Lambda$Pb. The $Lambda N$--$Sigma N$ coupling turn out to provide a contributionof about 23% (5%) to the total neutron--induced rate (proton--induced rate). Again as aneffect of the hyperon coupling,the total one--nucleon--induced rate increases by about 9%, while the $Gamma_n/Gamma_p$ratio increases by about 17%. The saturation property of the nonmesonic rates with increasinghypernuclear mass number is clearly obtained and explained. The above percentage modificationsremain almost unaltered through the hypernuclear mass number.All the non--negligible changes introduced by the $Lambda N$--$Sigma N$ coupling lead to adefinite improvement of our predictions once compared with the available KEK and FINUDA data.