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Related papers: Nuclear Level Density: Shell Model vs Mean Field

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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…

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

We perform a calculation of dense and hot nuclear matter where the mean interaction between nucleons is described by in-medium effective fields and where we employ analytical approximations of the Fermi integrals. We generalize a previous…

Nuclear Theory · Physics 2024-04-19 Odilon Lourenço , Mariana Dutra , Jérôme Margueron

We compute the level density of a two--component Fermi gas as a function of the number of particles, angular momentum and excitation energy. The result includes smooth low--energy corrections to the leading Bethe term (connected to a…

Nuclear Theory · Physics 2008-11-26 Patricio Leboeuf , Jérôme Roccia

The shell model Monte Carlo (SMMC) method enables calculations in model spaces that are many orders of magnitude larger than those that can be treated by conventional methods, and is particularly suitable for the calculation of level…

Nuclear Theory · Physics 2015-06-18 Y. Alhassid , M. Bonett-Matiz , S. Liu , A. Mukherjee , H. Nakada

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

We present some results and remarks based on a combinatorial approach of the evaluation of the nuclear level density. First, we show that it is possible to extract some reliable information from the output of the program whose rough data…

Nuclear Theory · Physics 2007-05-23 Bernard PICHON CNRS

Nuclear Astrophysics requires the knowledge of reaction rates over a wide range of nuclei and temperatures. In recent calculations the nuclear level density - as an important ingredient to the statistical model (Hauser-Feshbach) - has shown…

Astrophysics · Physics 2009-10-28 T. Rauscher , F. -K. Thielemann , K. -L. Kratz

We review recent advances in the shell model Monte Carlo approach for the microscopic calculation of statistical and collective properties of nuclei. We discuss applications to the calculation of (i) level densities in nickel isotopes,…

Nuclear Theory · Physics 2016-01-05 Y. Alhassid

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 nuclear shell model assumes an effective mean-field plus interaction Hamiltonian in a specific configuration space. We want to understand how various interaction matrix elements affect the observables, the collectivity in nuclei and the…

Nuclear Theory · Physics 2017-04-07 S. Karampagia , A. Renzaglia , V. 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

Realistic nuclear level densities (NLDs) obtained within the spectral distribution method (SDM) are employed to study nuclear processes of astrophysical interest. The merit of SDM lies in the fact that the NLDs corresponding to many body…

Nuclear Theory · Physics 2022-05-04 Sangeeta , T. Ghosh , B. Maheshwari , G. Saxena , B. K. Agrawal

The main formalisms of partial level densities (PLD) used in preequilibrium nuclear reaction models, based on the equidistant spacing model (ESM), are considered. A collection of FORTRAN77 functions for PLD calculation by using 14…

Computational Physics · Physics 2009-10-31 M. Avrigeanu , V. Avrigeanu

Recent results connected to nuclear collision dynamics, from low up to relativistic energies, are reviewed. Heavy ion reactions offer the unique opportunity to probe the complex nuclear many-body dynamics and to explore, in laboratory…

Nuclear Theory · Physics 2020-07-15 Maria Colonna

The properties of high-density nuclear and neutron matter are studied using a relativistic mean-field approximation to the nuclear matter energy functional. Based on ideas of effective field theory, nonlinear interactions between the fields…

Nuclear Theory · Physics 2009-10-30 Horst Mueller , Brian D. Serot

The nuclear density of states plays an important role in nuclear reactions. At high energies, above a few MeV, the nuclear density of states is well described by a formula that depends on the smooth single particle density of states at the…

Nuclear Theory · Physics 2007-05-23 Sanjay K. Ghosh , Byron K. Jennings

The Shell Model Monte Carlo (SMMC) approach has been applied to calculate level densities and partition functions to temperatures up to ~ 1.5 - 2 MeV, with the maximal temperature limited by the size of the configuration space. Here we…

Nuclear Theory · Physics 2009-11-10 Y. Alhassid , G. F. Bertsch , L. Fang

Performing a shell model calculation for heavy nuclei has been a long-standing problem in nuclear physics. Here we propose one possible solution. The central idea of this proposal is to take the advantages of two existing models, the…

Nuclear Theory · Physics 2009-11-10 Yang Sun , Cheng-Li Wu

Level density $\rho(E,N,Z)$ is derived for a nuclear system with a given energy $E$, neutron $N$, and proton $Z$ particle numbers, within the semiclassical extended Thomas-Fermi and periodic-orbit theory beyond the Fermi-gas saddle-point…

Nuclear Theory · Physics 2021-12-06 A. G. Magner , A. I. Sanzhur , S. N. Fedotkin , A. I. Levon , S. Shlomo