2009/10/06 by C. Barbero, A. Mariano, Barbero, C. +3
Physics and Astronomy · #Nuclear physics research studies #Quantum Chromodynamics and Particle Interactions #Quantum, superfluid, helium dynamics #nucl-th
paper · pdf · doi:10.48550/arxiv.0910.1127
Changing content, 8 pages, 2 figures, 2 tables, submitted to Phys. Rev. C
arxiv created 2010/05/05 · arxiv updated 2010/05/06
We develop a theoretical framework for the evaluation of the coincidence number of pairs, NnN, and the asymmetry parameter, aΛ, in nonmesonic hypernuclear decay ΛN→ nN. The primary nomesonic weak hyperon-nucleon decay process is described through the independent particle shell model. When the effect of the strong interactions experimented by the two nucleons leaving the residual nucleus is included, we have in addition to the 2p1h primary configuration 2p'1h', 3p2h, 4p3h, ⋯, etc secondary ones. We work within the 2p'1h' subspace of final states assuming a simple approach for finite nuclei based on the eikonal approximation. An optical potential including the nucleon-nucleus isoscalar and isovector interaction is introduced to take into account the minimum nuclear medium effects and to describe the nucleon-nucleus dispersion process along the outgoing path. We applied the proposed description to the calculation of the observables in 5ΛHe and 12ΛC nonmesonic decays. The calculated results show that our treatment of FSI even considered as restricted to a subspace of states gives a good agreement with experimental data, similar to that ones presented by more elaborated evaluations. This indicates that the developed theoretical scheme seems to be appropriated to include more complex configurations. We also discuss the ground state normalization effects at the moment of including the two-nucleon induced decay (ΛNN → nNN) contribution.