Study of the $\eta-^7Be$ Interaction Near Threshold in $p-^6Li$ Fusion
  We present a calculation for $\eta$ production in the $p-^6Li$ fusion near threshold including the $\eta-^7Be$ final state interaction (FSI). We consider the $^6Li$ and $^7Be$ nuclei as $\alpha-d$ and $\alpha-^3He$ clusters respectively. The calculations are done for the lowest states of $^7Be$ with $J = ({3\over2}^-, {1\over2}^-)$ resulting from the $L = $1 radial wave function. The $\eta-^7Be$ interaction is incorporated through the $\eta-^7Be$ $T-$matrix, constructed from the medium modified matrices for the $\eta-^3He$ and $\eta-\alpha$ systems. These medium modified matrices are obtained by solving few body equations, where the scattering in nuclear medium is taken into account. 
N. J. Upadhyay, N. G. Kelkar, K. P. Khemchandani, B. K. Jain