Eur. Phys. J. A (2007) 32: 19-23
https://doi.org/10.1140/epja/i2007-10366-9

Regular Article - Nuclear Structure and Reactions

Nuclear giant resonances and linear response

¹ Institut für Theoretische Physik II, Universität Erlangen, D-91058, Erlangen, Germany
² Institut für Theoretische Physik, Universität Frankfurt, D-60438, Frankfurt am Main, Germany

Received: 14 March 2007
Accepted: 13 April 2007
Published online: 7 May 2007

Abstract

We search for nonlinear effects in nuclear giant resonances (GRs), in particular the isovector dipole and the isoscalar quadrupole modes. To that end, we employ a spectral analysis of time-dependent Hartree-Fock (TDHF) dynamics using Skyrme forces. Based on TDHF calculations over a wide range of excitation amplitudes, we explore the collectivity and degree of harmonic motion in these modes. Both GR modes turn out to be highly harmonic in heavy nuclei from A = 100 on. There is no trace of a transition to irregular motion and multiple resonances are predicted. Slight anharmonicities are seen for light nuclei, particularly for ¹⁶O. These are mainly caused by the spin-orbit splitting.