Naslov
Relativistic QRPA description of excitations in exotic nuclei

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

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Structure and Dynamics of Elementary Matter, NATO Science Series, II. Mathematics, Physics and Chemistry - Vol.166 / Greiner, W. ; Itkis, M.G. ; Reinhardt, J. ; Güçlü, M.C. - Dordrecht : Kluwer Academic Publishers, 2004, 661-663

Skup
Structure and Dynamics of Elementary Matter

Mjesto i datum
Çamyuva, Turska, 22.09.2003. - 02.10.2003

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Structure of exotic nuclei; relativistic mean-field model; QRPA; giant resonances

Sažetak
The relativistic random phase approximation (RRPA) has been employed in the analysis of the evolution of the isovector dipole response in nuclei with a large neutron excess~$^{; ; ; 1, 2)}; ; ; $. The dipole response is characterized by the fragmentation of the strength distribution and its spreading into the low-energy region, and by the mixing of isoscalar and isovector modes. In light nuclei the onset of dipole strength in the low-energy region is due to single particle excitations of the loosely bound neutrons. In heavier nuclei, low-lying dipole states appear which are characterized by a more distributed structure of the RRPA amplitude, exhausting approximately 2\% of the EWSR. Among several peaks characterized by single particle transitions, a single collective isovector dipole state is identified below 10 MeV. An analysis of the corresponding transition densities and velocity distributions reveals the dynamics of the dipole pygmy resonance: the vibration of the excess neutrons against the inert core composed of equal numbers of protons and neutrons.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA