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Related papers: Nuclear Level Densities in the Constant-Spacing Mo…

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Starting from an independent-particle model with a finite and arbitrary set of single-particle energies, we develop an analytical approximation to the many-body level density $\rho_A(E)$ and to particle-hole densities. We use exact…

Nuclear Theory · Physics 2013-09-30 Adriana Pálffy , Hans A. Weidenmüller

The knowledge of the nuclear level density is necessary for understanding various reactions including those in the stellar environment. Usually the combinatorics of Fermi-gas plus pairing is used for finding the level density. Recently a…

Nuclear Theory · Physics 2016-06-22 Roman Sen'kov , Vladimir Zelevinsky

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…

Nuclear Theory · Physics 2008-11-26 R. Pezer , A. Ventura , D. Vretenar

The level density is among the most important statistical nuclear properties. It appears in Fermi's golden rule for transition rates and is an important input to the Hauser-Feshbach theory of compound nucleus reactions. We discuss empirical…

Nuclear Theory · Physics 2022-01-05 Y. Alhassid

The prediction of cross sections for nuclei far off stability is crucial in the field of nuclear astrophysics. In recent calculations the nuclear level density -- as an important ingredient to the statistical model (Hauser-Feshbach) -- has…

Astrophysics · Physics 2016-08-30 T. Rauscher , F. -K. Thielemann , K. -L. Kratz

It is almost 80 years since Hans Bethe described the level density as a non-interacting gas of protons and neutrons. In all these years, experimental data were interpreted within this picture of a fermionic gas. However, the renewed…

We present calculations of nuclear level densities that are based upon the detailed microphysics of the interacting shell model yet are also computationally tractable. To do this, we combine in a novel fashion several previously disparate…

Nuclear Theory · Physics 2007-05-23 Calvin W. Johnson , Jameel-Un Nabi , W. Erich Ormand

Nucleosynthesis calculations require nuclear level densities for hundreds or even thousands of nuclides. Ideally one would like to constrain these level densities by microscopically motivated yet computationally cheap models. A statistical…

Nuclear Theory · Physics 2007-05-23 Jameel-Un Nabi , Calvin W. Johnson , W. Erich Ormand

Nuclear level density is calculated with the combinatorial method based on the relativistic density functional theory including pairing correlations. The Strutinsky method is adopted to smooth the total state density in order to refine the…

Nuclear Theory · Physics 2024-01-18 Xiao-Fei Jiang , Xin-Hui Wu , Peng-Wei Zhao , Jie Meng

Level density $\rho$ is derived for a finite system with strongly interacting nucleons at a given energy E, neutron N and proton Z particle numbers, projection of the angular momentum M, and other integrals of motion, within the…

Nuclear Theory · Physics 2023-08-22 A. G. Magner , A. I. Sanzhur , S. N. Fedotkin , A. I. Levon , U. V. Grygoriev , S. Shlomo

A new algorithm for calculating the spin- and parity-dependent shell model nuclear level densities using the moments method in the proton-neutron formalism is presented. A new, parallelized code based on this algorithm was developed and…

Nuclear Theory · Physics 2014-11-20 R. A. Sen'kov , M. Horoi

The modern form of the Moments Method applied to the calculation of the nuclear shell-model level density is explained and examples of the method at work are given. The calculated level density practically exactly coincides with the result…

Nuclear Theory · Physics 2016-01-27 V. Zelevinsky , M. Horoi , R. A. Sen'kov

We introduce a novel method to obtain level densities in large-scale shell-model calculations. Our method is a stochastic estimation of eigenvalue count based on a shifted Krylov-subspace method, which enables us to obtain level densities…

We present a new combinatorial method for the calculation of the nuclear level density. It is based on a Monte Carlo technique, in order to avoid a direct counting procedure which is generally impracticable for high-A nuclei. The Monte…

Nuclear Theory · Physics 2008-11-26 N. Cerf

In the independent-particle model, the nuclear level density is determined from the neutron and proton single-particle level densities. The single-particle level density for the positive-energy continuum levels is important at high…

Nuclear Theory · Physics 2009-11-10 R. J. Charity , L. G. Sobotka

Accurate knowledge of the nuclear level density is important both from a theoretical viewpoint as a powerful instrument for studying nuclear structure and for numerous applications. For example, astrophysical reactions responsible for the…

Nuclear Theory · Physics 2017-10-10 S. Karampagia , R. A. Senkov , V. Zelevinsky

A new high-performance algorithm for calculating the spin- and parity-dependent shell model nuclear level densities using methods of statistical spectroscopy in the proton-neutron formalism was recently proposed. When used in valence spaces…

Nuclear Theory · Physics 2011-08-17 R. A. Sen'kov , M. Horoi , V. G. Zelevinsky

Level density $\rho(E,N,Z)$ 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…

Nuclear Theory · Physics 2023-08-16 A. G. Magner , A. I. Sanzhur , S. N. Fedotkin , A. I. Levon , U. V. Grygoriev , S. Shlomo

A microscopic method for calculating nuclear level densities (NLD) is developed, based on the framework of energy density functionals. Intrinsic level densities are computed from single-quasiparticle spectra obtained in a finite-temperature…

Nuclear Theory · Physics 2020-11-18 Jie Zhao , Tamara Nikšić , Dario Vretenar

The work presents a proof of convergence of the density of energy levels to a Gaussian distribution for a wide class of quadratic forms of Fermi operators. This general result applies also to quadratic operators with disorder, e.g.,…

Mathematical Physics · Physics 2017-06-28 Fabio Deelan Cunden , Anna Maltsev , Francesco Mezzadri
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