Possible relevance of the softening of the sigma meson to $\eta$ decay into 3$\pi$ in the nuclear medium

Shuntaro Sakai, Teiji Kunihiro

We investigate the role of the softening of the scalar-isoscalar (sigma) meson in the $\eta \to {\pi }^{+}{\pi }^{-}{\pi }^0$ and $3{\pi }^0$ decay widths in the symmetric nuclear medium using a linear…