Nuclear in-medium effects on $\eta$ dynamics in proton-nucleus   collisions
  The dynamics of $\eta$ meson produced in proton-induced nuclear reactions via the decay of N$^{\ast}(1535)$ has been investigated within the Lanzhou quantum molecular dynamics transport model (LQMD). The in-medium modifications of the $\eta$ production in dense nuclear matter are included in the model, in which an attractive $\eta$-nucleon potential is implemented. The impact of the $\eta$ optical potential on the $\eta$ dynamics is investigated. It is found that the attractive potential leads to the reduction of high-momentum (kinetic energy) production from the spectra of momentum distributions and inclusive cross sections and increasing the reabsorption process by surrounding nucleons. 
Jie Chen, Zhao-Qing Feng, Jian-Song Wang
nucl-th