Time-dependent aspects of the semiclassical approach in the analysis of heavy ion reactions

Abstract

The semiclassical approach is one of the fundamental tools used to investigate and analyze heavy ion reaction processes. We show in this contribution that the evolution of the motion that emerges from the knowledge of the semiclassical amplitudes for the reaction channels as a function of time cannot be taken as a reliable representation for an actual wave function of the intrinsic states.

Relativistic nuclear excitation—A new approach

“…We could, in principle, choose for the illustrations the same system as in Refs. [11,13]. Such choice would certainly ease the comparison of the new results with figures that already appeared in these earlier works.…”

“…The scheme of Ref. [11] benefits from a previous work [13] where it was shown that a classical approach, complemented by well-tested quantification rules, can indeed reproduce those results with remarkable precision.…”

“…the system of Ref. [11]. The figure also includes, however, the traditional system S , invoked in Appendix A, where we investigate the approximate validity of the relativistic boosting prescription.…”

“…[11] it was noted that an appealing advantage of the new approach is that it allows for the simple introduction of other excitation fields. In fact, once one has paid the price of converting relativistically Hooke's law and is geared to solve Einstein's instead of Newton's equations of motion, the inclusion of other excitation mechanisms becomes straightforward, as there are no further Lorentz transformations involved.…”

“…In a recent publication [11] the problem of relativistic Coulomb excitation was recast in a way in which the commonly used Liénard-Wiechert relativistic potentials need not be invoked. The goal was here to reproduce the excitation probabilities for the one-and two-phonon states of the Giant Dipole Resonance (GDR) obtained according to the conventional treatment of [3] in elaborate coupled-channel calculations by Bayman and Zardi [12].…”