Dynamical Coupling of Pygmy and Giant Resonances in Relativistic Coulomb Excitation

TL;DR

This paper investigates how giant resonances influence the excitation of pygmy dipole resonances during relativistic Coulomb excitation in heavy ion collisions, highlighting the importance of coupled reaction dynamics.

Contribution

It demonstrates the significant impact of giant resonance coupling on PDR excitation probabilities, emphasizing the need for improved theoretical models.

Findings

Giant resonances strongly affect PDR excitation probabilities

Coupling effects are significant at 100 MeV/nucleon energies

Results suggest revising reaction dynamic models for better accuracy

Abstract

We study the Coulomb excitation of pygmy dipole resonances (PDR) in heavy ion reactions at 100 MeV/nucleon and above. The reactions 68Ni+197Au and 68Ni+208Pb are taken as a practical examples. Our goal is to address the question of the influence of giant resonances on the PDR as the dynamics of the collision evolves. We show that the coupling to the giant resonances affects considerably the excitation probabilities of the PDR, a result that indicates the need of an improved theoretical treatment of the reaction dynamics at these bombarding energies.