https://doi.org/10.1140/epja/s10050-023-01222-1
Regular Article - Theoretical Physics
Pairing correlations within the micro-macroscopic approach for the level density
1
Institute for Nuclear Research, 03028, Kyiv, Ukraine
2
Cyclotron Institute, Texas A &M University, 77843, College Station, TX, USA
3
University of Groningen, 9712 TS, Groningen, The Netherlands
Received:
14
August
2023
Accepted:
12
December
2023
Published online:
8
January
2024
Level density 
is calculated for the two-component close- and open-shell nuclei with a given energy E, and neutron N and proton Z numbers, taking into account pairing effects within the microscopic-macroscopic approach (MMA). These analytical calculations have been carried out by using semiclassical statistical mean-field approximations beyond the saddle-point method of the Fermi gas model in a low excitation-energies range. The level density 
, obtained as function of the system entropy S, depends essentially on the condensation energy 
through the excitation energy U in super-fluid nuclei. The simplest super-fluid approach, based on the BCS theory, accounts for a smooth temperature dependence of the pairing gap 
due to particle number fluctuations. Taking into account the pairing effects in magic or semi-magic nuclei, excited below neutron resonances, one finds a notable pairing phase transition. Pairing correlations sometimes improve significantly the comparison with experimental data.
Copyright comment Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
