Direct measurement of the in-medium ${\eta }^{\prime }$ mass spectrum through the $\gamma \gamma$ decay channel

Y. Matsumura, N. Muramatsu, T. A. Hashimoto +58

We measured the invariant mass of the ${\eta }^{\prime }(958)$ meson through the ${\eta }^{\prime }\to \gamma \gamma$ decay channel to search for possible character change of ${\eta }^{\prime }$ in a nuclear mediu…