Gießen 2007 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

HK: Fachverband Physik der Hadronen und Kerne

HK 25: Kernphysik / Spektroskopie

HK 25.2: Vortrag

Mittwoch, 14. März 2007, 11:30–11:45, D

Shape fluctuation and the collisional damping width of the giant dipole resonance in A∼84 — •Sarla Rathi — Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany

One of the important issues in the GDR studies is to separate the contributions of the widths from the different damping mechanisms so that their dependence on temperature (T) and angular momentum (J) can be studied. The spreading of the GDR strength is mainly due to the collisional damping and the shape fluctuations. In this field, there are many open questions, both in theory and experiment. The thermal shape fluctuation model (TSFM) has been reasonably successful in explaining the data, except in certain nuclei like Cu, Sn, Au, Pb at low T. We shall present the comparison of the experimental results in the mass region A∼84 with a phenomenological model [1]. The collisional damping width (Γ₀) in the system ²⁸Si +⁵⁸Ni [2], (which lies away from the nearby stable nuclei) has been extracted using the shape fluctuation model analysis. The energy dependent average strength function is calculated and used in the statistical model code CASCADE. The calculated gamma spectrum is then compared with the experimental one to extract the value of Γ₀. Further, results on the exclusive T and J dependence of Γ₀ will be reported.
[1] D. Kusnezov, Y. Alhassid, and K. A. Snover, Phys. Rev. Lett. 81, 542 (1998).
[2] S. Rathi, Phys. Rev. C. 74, 024608 (2006).