Energy and width ofΣhyperon in nuclear matter

Abstract

The width $\Gamma$ and the potential well depth $-V_{\Sigma }$ of the $\Sigma$ hyperon in nuclear matter are calculated with the help of the Brueckner theory. Results obtained for $\Gamma$ and $V_{\Sigma }$ with model D of the Nijmegen baryon-baryon interaction and simple estimates of $\Gamma$ in terms of the cross section for the ${\Sigma }^{-}p\to \Lambda n$ process are consistent with empirical estimates. It is shown that the exclusion principle and dispersive effects strongly suppress the $\Sigma N\to \Lambda N$ process in nuclear matter and are capable of reducing $\Gamma$ to values suggested by recent ($K,\pi$) experiments.