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Related papers: Parity Dependence of Nuclear Level Densities

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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

Collective effects in the level density are not well understood, and including these effects as enhancement factors to the level density does not produce sufficiently consistent predictions of observables. Therefore, collective effects are…

Nuclear Theory · Physics 2014-06-19 Bora Canbula , Ramazan Bulur , Deniz Canbula , Halil Babacan

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

Even tin isotopes of mass number $A = 108 \sim 124$ are calculated with realistic interactions in the generalized-seniority approximation of the nuclear shell model. For each nucleus, we compute the lowest ten thousand states ($5000$ of…

Nuclear Theory · Physics 2016-10-26 L. Y. Jia , Chong Qi

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 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

Information on level density for nuclei with mass numbers A = 20 - 250 is deduced from discrete low-lying levels and neutron resonance data. The odd-mass nuclei exhibit in general 4 - 7 times the level density found for its neighboring…

Nuclear Experiment · Physics 2009-10-31 M. Guttormsen , M. Hjorth-Jensen , E. Melby , J. Rekstad , A. Schiller , S. Siem

The interplay of pairing is explored for the spectral statistics of nuclear systems with emphasis on the nearest neighbor spacing distributions by employing the kernel density and maximum likelihood estimation techniques. Different…

Nuclear Theory · Physics 2013-06-25 H. Sabri , B. Rashidian Maleki , J. Fouladi , N. Fouladi , M. A. Jafarizadeh

We present analytical estimates and numerical calculations showing that the energy level density in open-shell atoms increases exponentially with increase of excitation energy. As an example, we use the relativistic Hartree-Fock and…

Atomic Physics · Physics 2015-05-18 V. A. Dzuba , V. V. Flambaum

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

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

We extend the shell-model Monte Carlo applications to the rare-earth region to include the odd-even nucleus ${}^{161}$Dy. The projection on an odd number of particles leads to a sign problem at low temperatures making it impractical to…

Nuclear Theory · Physics 2015-06-05 Cem Özen , Yoram Alhassid , Hitoshi Nakada

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

A new method to calculate level densities for non-interacting Fermions within the constant-spacing model with a finite number of states is developed. We show that asymptotically (for large numbers of particles or holes) the densities have…

Nuclear Theory · Physics 2013-01-08 Adriana Pálffy , Hans A. Weidenmüller

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

It has long been observed that the number of weak lines from many-electron atoms follows a power law distribution of intensity. While computer simulations have reproduced this dependence, its origin has not yet been clarified. Here we…

Atomic Physics · Physics 2020-05-13 Keisuke Fujii , Julian C. Berengut

Spectral functions of the nucleon and its negative parity excited state in nuclear matter are studied using QCD sum rules and the maximum entropy method (MEM). It is found that in-medium modifications of the spectral functions are…

High Energy Physics - Phenomenology · Physics 2016-10-14 Keisuke Ohtani , Philipp Gubler , Makoto Oka

We investigate the nature and impact of shell effects on nuclear level density (NLD) and particle emission probability as a function of temperature in a microscopic theoretical framework of Statistical Model for nuclei ranging from neutron…

Nuclear Theory · Physics 2023-03-03 Mamta Aggarwal

Excitation energies and transition probabilities of the first $2^+$ excitations in even tin and lead isotopes as well as the quadrupole moments of odd neighbors of these isotopes are calculated within the self-consistent Theory of Finite…

Nuclear Theory · Physics 2013-05-29 S. V. Tolokonnikov , S. Kamerdzhiev , D. Voytenkov , S. Krewald , E. E. Saperstein

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…