Finite Range Effects in Knockout Reactions

Finite Range DWIA calculations have been performed for the first time. For the $(\alpha ,2\alpha )$ reactions, the calculations have indicated extreme sensitivity to the short range component of the t-matrix effective interaction. The vagaries of the energy dependent $\alpha $-spectroscopic factors, have been understood using well established nuclear data. Using repulsive core $\alpha -\alpha $ interaction two order of magnitude enhancement is explained. FR-DWIA calculation is a new tool to investigate the nature of nuclear potential. Heavy cluster knockout reaction such as ${ }^{16}O({ }^{12}C,2{ }^{12}C){ }^4He$has been performed for the first time indicating an order of magnitude enhancement compared to the $(\alpha ,2\alpha )$ results. The (C,2C) results support a short range repulsive core C-C potential. Similar study can be made to probe the short range behavior of $p-p$, $\pi -p$and $K^+n$systems to study the dibaryons, delta resonances and the pentaquarks. A new field of Heavy Cluster Knockout Reaction is opened up to study the core knockout of Halo nuclei. Our FR-DWIA formalism has applications in Atomic and Molecular Physics and neutron multiplication calculations for ADS also.