Naslov
Relativistic QRPA description of low-lying dipole strength in neutron-rich nuclei

Autori
Vretenar, Dario ; Nikšić, Tamara ; Paar, Nils ; Ring, Peter

Izvornik
Nuclear Physics A (0375-9474) 731 (2004), 1; 281-288

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
relativistic quasi-particle random phase approximation; giant resonances; pygmy resonances

Sažetak
The relativistic quasi-particle random phase approximation (RQRPA) is applied in the analysis of the evolution of isovector dipole response in nuclei with large neutron excess. In neutron-rich nuclei the dipole response is characterized by the fragmentation of the strength distribution and its spreading into the low-energy region. In light nuclei the onset of dipole strength in the low-energy region is due to non-resonant single-particle excitations of the loosely bound neutrons. In heavier neutron-rich nuclei low-lying dipole states appear which display a more distributed structure of the RQRPA amplitudes. For these nuclei a single collective dipole state is identified in the low-energy region, and an analysis of the corresponding transition densities and velocity distributions reveals the dynamics of the pygmy resonance.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA