Constraints on $\Sigma$ Nucleus Dynamics from Dirac Phenomenology of $\Sigma^-$ Atoms

摘要

Strong interaction level shifts and widths in $\Sigma^-$ atoms are analyzedby using a $\Sigma$ nucleus optical potential constructed within therelativistic mean field approach. The analysis leads to potentials with arepulsive real part in the nuclear interior. The data are sufficient toestablish the size of the isovector meson--hyperon coupling. Implications to$\Sigma$ hypernuclei are discussed.