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Related papers: Nuclear level density in the statistical semiclass…

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We use quantum Monte Carlo methods in the framework of the interacting nuclear shell model to calculate the statistical properties of nuclei at finite temperature and/or excitation energies. With this approach we can carry out realistic…

Nuclear Theory · Physics 2009-11-11 Y. Alhassid

Nuclear level densities are crucial for estimating statistical nuclear reaction rates. The shell model Monte Carlo method is a powerful approach for microscopic calculation of state densities in very large model spaces. However, these state…

Nuclear Theory · Physics 2013-04-29 Y. Alhassid , M. Bonett-Matiz , S. Liu , H. Nakada

Photon strength, $f(E_{\gamma})$, measured in photonuclear reactions, is the product of the average level density per MeV, $\rho(E_x)$, and the average reduced level width, $\Gamma_{\gamma}/E_{\gamma}^3$ for levels populated primarily by E1…

Nuclear Theory · Physics 2021-06-18 R. B. Firestone

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

We calculate microscopically total and parity-projected level densities for $\beta$-stable even-even nuclei between Fe and Ge, using the shell model Monte Carlo methods in the complete $(pf+0g_{9/2})$-shell. A single-particle level density…

Nuclear Theory · Physics 2009-10-31 H. Nakada , Y. Alhassid

We discuss the role of mean-field and moment methods in microscopic models for calculating the nuclear density of states (also known as the nuclear level density). Working in a shell-model framework, we use moments of the nuclear many-body…

Nuclear Theory · Physics 2007-05-23 Calvin W. Johnson , Edgar Teran

Nonuniform structure of low-density nuclear matter, known as nuclear pasta, is expected to appear not only in the inner crust of neutron stars but also in core-collapse supernova explosions and neutron-star mergers. We perform fully…

Nuclear Theory · Physics 2021-05-19 Fan Ji , Jinniu Hu , Hong Shen

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

The nuclear level densities and level-density parameters in fissioning nuclei at their saddle points of fission barriers - $a_{f}$, as well as those for neutron - $a_{n}$, proton - $a_{p}$ , and $\alpha$-particle - $a_{\alpha}$ emission…

Nuclear Theory · Physics 2021-08-31 A. Rahmatinejad , T. M. Shneidman , G. Adamian , N. V. Antonenko , P. Jachimowicz , M. Kowal

A fully microscopic model for the description of nuclear level density (NLD) in spherical nuclei is proposed. The model is derived by combining the partition function of the exact pairing solution plus the independent-particle model at…

Nuclear Theory · Physics 2020-12-02 N. Quang Hung , N. Dinh Dang , L. Tan Phuc , N. Ngoc Anh , T. Dong Xuan , T. V. Nhan Hao

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

The isospin dependence of nuclear level density has been investigated by analyzing the spectra of evaporated neutrons from excited $^{116}$Sn and $^{116}$Te nuclei. These nuclei are populated via $p$ + $^{115}$In and $^{4}$He + $^{112}$Sn…

We systematically study the nuclear level densities of superheavy nuclei, including odd systems, using the single-particle energies obtained with the Woods-Saxon potential diagonalization. Minimization over many deformation parameters for…

Background: Exotic non-spherical nuclear pasta shapes are expected in nuclear matter at just below saturation density because of competition between short range nuclear attraction and long range Coulomb repulsion. Purpose: We explore the…

Nuclear Theory · Physics 2015-07-01 M. E. Caplan , A. S. Schneider , C. J. Horowitz , D. K. Berry

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

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

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

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

The spin and parity dependent nuclear level densities (NLD) are calculated for medium-heavy nuclei using shell model techniques. The NLD are used to calculate cross sections and reaction rates of interest for nuclear astrophysics and…

Nuclear Theory · Physics 2018-01-17 Mihai Horoi , Jayani Dissanayake

The symmetry energy coefficients for nuclei with mass number A=20~250 are extracted from more than 2000 measured nuclear masses. With the semi-empirical connection between the symmetry energy coefficients of finite nuclei and the nuclear…

Nuclear Theory · Physics 2010-12-28 Min Liu , Ning Wang , Zhuxia Li , Fengshou Zhang