Exchange terms in the two--nucleon induced non--mesonic weak decay of $\Lambda$--hypernuclei

Abstract

The contribution of Pauli exchange terms to the two--nucleon induced non--mesonic weak decay of ${}_{\Lambda }^{12}$C hypernuclei, $\Lambda NN\to nNN$ ($N=n$ 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. 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 non--mesonic decay widths in theoretical and experimental analyses.

14 pages, 3 figures

References in corpus (5)

• Hypernuclear Physics for Neutron Stars
• Mesonic and nonmesonic weak decay widths of medium-heavy lambda hypernuclei
• Two-pion-exchange in the non-mesonic weak decay of $\Lambda$-hypernuclei
• Quantum interference terms in nonmesonic weak decay of $\Lambda$-hypernuclei within a RPA formalism
• Ground state normalization in the nonmesonic weak decay of ${}_{\Lambda }^{12}C$ hypernucleus within a nuclear matter formalism