Strangeness Modes in Nuclei Tested by Anti-Neutrinos

Abstract

Production of negative strangeness in reactions of inelastic anti-neutrino scattering on a nucleus provides information on the modification of strange degrees of freedom in nuclear matter. We calculate cross-sections of the reaction channels $\barν_{e(μ)}\to e^+(μ^+) + K^{-}$ and $\barν_{e(μ)} + p \to \Lb + e^+(μ^+)$ and investigate their sensitivity to the medium effects. In particular, we consider effects induced by the presence of a low-energy excitation mode in the $K^-$ spectrum, associated with the correlated $Λ$-particle and proton-hole states, and the renormalization of the weak interaction in medium. In order to avoid double counting, various contributions to anti-neutrino scattering are classified with the help of the optical theorem, formulated within the non-equilibrium Green's function technique.