Excitation energy and angular momentum dependence of nuclear level densities and spin cut-off factor in SPA and SPA + RPA approaches

✍ Scribed by B.K. Agrawal; A. Ansari

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 502 KB
• Volume: 640
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(98)00462-x

✦ Synopsis

We investigate the excitation energy (E*) and angular momentum (J) dependence of nuclear level density and spin cut-off factor (o-) within microscopic approaches based on SPA and its extension SPA + RPA representation of the grand partition function for quadrupole-quadrupole interaction model Hamiltonian. For l~°Sn, we find that excitation energy dependence of the total level density obtained within these approaches is significantly different. On the other hand, these approaches yield similar behaviour for J-dependence of the level density at fixed values of E*. Values of O' SPA + RPA at low E* are found to be slightly smaller than O' SPA but they tend to become almost the same at higher E*(> 30 MeV). We also find that Bethe's formula for fixed-J level density based on the spin cut-off approximation can be used to compute p(E*, J) near the yrast line provided one uses an appropriate value of the spin cut-off factor. (~) 1998 Elsevier Science B.V.