Impact of magnetic field on the giant dipole resonance ofCa40using an extended quantum molecular dynamics model

Abstract

By taking into account the magnetic field in the extended quantum molecular dynamics model, we analyzed its effects on giant dipole resonance (GDR) by studying the responses and strengths of the dipole moments. The selected system is the $^{40}\mathrm{Ca}$ nucleus which is excited through the Coulomb interaction by $^{16}\mathrm{O}$. The particle acceleration term in the Li\'enard-Wiechert potential is discussed which, however, has small impact on the magnetic field. The peak energy, strength, and width of GDR, temperature, and angular momentum of $^{40}\mathrm{Ca}$ as a function of beam energy are investigated. It is found that the magnetic field enhances the peak energy, strength, and width of GDR which is not only due to the temperature effects, but also due to the enhancement of the angular momentum of nucleus. At beam energy $E >$ 200 MeV/nucleon, the magnetic field maintains a constant value for the strength of GDR. The paper sheds light on examining important roles of the magnetic field on the nuclear structure in low-intermediate energy heavy-ion collisions.