Exchange terms in the two-nucleon induced non-mesonic weak decay of Λ-hypernuclei

✍ Scribed by E. Bauer; G. Garbarino

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 395 KB
• Volume: 828
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/j.nuclphysa.2009.06.022

✦ Synopsis

The contribution of Pauli exchange terms to the two-nucleon induced non-mesonic weak decay of 12 Λ C hypernuclei, ΛN N → nN N (N = n or p), is studied within a nuclear matter formalism implemented in a local density approximation. We have adopted a weak transition potential including the exchange of the complete octets of pseudoscalar and vector mesons as well as a residual strong interaction modeled on the Bonn potential. Among the exchange contributions, only the dominant ones have been evaluated microscopically from the corresponding Goldstone diagrams; a Landau-Migdal model has been adopted for the remaining exchange terms. The introduction of exchange terms turns out to reduce the two-nucleon induced non-mesonic rate by 18% and, jointly with an increase in the one-nucleon induced rate by the same magnitude, reveals to be significant for an accurate determination of the full set of hypernuclear nonmesonic decay widths in theoretical and experimental analyses.