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Combinatorial Level Densities from a Microscopic Relativistic Structure Model

R. Pezer·A. Ventura·D. Vretenar
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Abstract

A new model for calculating nuclear level densities is investigated. The single-nucleon spectra are calculated in a relativistic mean-field model with energy-dependent effective mass, which yields a realistic density of single-particle states at the Fermi energy. These microscopic single-nucleon states are used in a fast combinatorial algorithm for calculating the non-collective excitations of nuclei. The method, when applied to magic and semi-magic nuclei, such as $^{60}$Ni, $^{114}$Sn and $^{208}$Pb, reproduces the cumulative number of experimental states at low excitation energy, as well as the s-wave neutron resonance spacing at the neutron binding energy. Experimental level densities above 10 MeV are reproduced by multiplying the non-collective level densities by a simple vibrational enhancement factor. Problems to be solved in the extension to open-shell nuclei are discussed

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R. Pezer, A. Ventura, D. Vretenar. 2003-01-17. Combinatorial Level Densities from a Microscopic Relativistic Structure Model. https://doi.org/10.1016/s0375-9474(03)00614-6

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