IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
A Theoretical Determination of N_{nn}/N_{np} in Hypernuclear Non--Mesonic Weak Decay
Autor/es:
E. BAUER, G. GARBARINO
Lugar:
Tokai, JapĆ³n
Reunión:
Conferencia; Conference on Hypernuclear and Strange Particle Physics (Hyp-X),; 2009
Institución organizadora:
JPark
Resumen:
The ratio $N_{nn}/N_{np}$ between the number of neutron--neutronand neutron--proton pairs emittedin the non--mesonic weak decay of $\Lambda$--hypernuclei iscalculated within a nuclear matter formalism extended to$^{12}_{\Lambda}$C via the local densityapproximation. The single--nucleon emission spectra, $N_p$ and $N_n$, arealso evaluated. Our formalism takes care of bothground state correlations (gsc) and final state interactions (FSI).The evaluation of $N_{nn}/N_{np}$---~which, unlike $\Gamma_n/\Gamma_p\equiv\Gamma(\Lambda n\to nn)/\Gamma(\Lambda p\to np)$, is anactual observable quantity in non--mesonic decay~--- is performedwithin a fully microscopic model where a propertreatment of FSI, gsc and ground state normalization isconsidered. All the isospin channels contributingto one-- and two--nucleon induced decays are included.Our final result for the coincidence number ratio,$N_{nn}/N_{np}=0.374$, is in agreement withthe KEK--E508 datum, $(N_{nn}/N_{np})^{\rm exp}=0.40\pm 0.10$.
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