The optical model potential of the $\Sigma$ hyperon in nuclear matter

Abstract

We present our attempts to determine the optical model potential $U_{\Sigma }=V_{\Sigma }-i{W}_{\Sigma }$ of the $\Sigma$ hyperon in nuclear matter. We analyze the following sources of information on $U_{\Sigma }$: $\Sigma N$ scattering, ${\Sigma }^{-}$ atoms, and final state interaction of $\Sigma$ hyperons in the $(\pi ,K^{+})$ and $(K^{-}.\pi )$ reactions on nuclear targets. We conclude that $V_{\Sigma }$ is repulsive inside the nucleus and has a shallow a tractive pocket at the nuclear surface. These features of $V_{\Sigma }$ are consistent with the Nijmegen model F of the hyperon-nucleon interaction.

Comments: Presented at the XXXI Mazurian Lakes Conference on Physics, Piaski, Poland, August 30-September. 5, 2009}