A second random phase approximation formalism for non-relativistic nuclear matter is presented. Exchange terms are explicitly included. The scheme is applied to the calculation of the electromagnetic transverse structure function per unit volume for quasi-elastic electron scattering on nuclei at momentum transfer q = 410 MeV/c . A simple model for the residual interaction, consisting of a ( + )-meson exchange plus the g ´-Landau-Migdal parameter is employed.

The contribution of ground state correlations (GSC) to the non-mesonic weak decay of 12 Λ C and other medium to heavy hypernuclei is studied within a nuclear matter formalism implemented in a local density approximation. We adopt a weak transition potential including the exchange * Electronic address:

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. 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. Hypernuclei, bound systems of neutrons, protons and hyperons, embody an important source of information able to match nuclear and particle physics. On the one hand, studies on the production mechanisms and the structure of hypernuclei [1] are of interest since they provide indications on the hyperonnucleon and hyperon-hyperon strong interactions which cannot be determined with precision from scattering experiments (such experiments are very challenging due to the very short hyperon lifetimes). Hypernuclear weak decay is on the other hand the only available tool to acquire knowledge on the baryon-baryon strangeness-changing interactions [2-5]. The above subjects, which presuppose the solution of complex many-body problems, are in turn crucially related to the renormalization of hyperons and mesons properties in