Hard thermal loop effective actions are quite useful in studying properties of quark-gluon plasma. They arise from loop corrections at high temperature have very unique properties. In this talk we will try to discuss using the proper time method of Schwinger how such interesting properties arise in the structure of the hard thermal loop effective action

Abstract Nuclei as finite quantum objects exhibit a variety of structures in their ground and excited states. Collisions between two heavy nuclei at medium bombarding energies lead to different phenomena depending on the impact parameter of the collision. Various studies have indicated that the structure of projectile and target nuclei play important role in deciding the reaction dynamics in heavy ion collisions. The present talk will provide a glimpse of certain aspects of the effect of nuclear structure in heavy ion collisions leading to fusion, transfer and fission reactions.