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Related papers: Statistical Properties of Nuclei by the Shell Mode…

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The shell-model Monte Carlo (SMMC) technique transforms the traditional nuclear shell-model problem into a path-integral over auxiliary fields. We describe below the method and its applications to four physics issues: calculations of sdpf-…

Nuclear Theory · Physics 2009-10-31 D. J. Dean , J. A. White

Total and parity-projected level densities of iron-region nuclei are calculated microscopically by using Monte Carlo methods for the nuclear shell model in the complete $(pf+0g_{9/2})$-shell. The calculated total level density is found to…

Nuclear Theory · Physics 2007-05-23 H. Nakada , Y. Alhassid

We present Shell Model Monte Carlo calculations for nuclei within the full major shell 50-82 for both protons and neutrons. The interaction is determined solely by self-consistency and odd-even mass differences. The methods are illustrated…

Nuclear Theory · Physics 2009-01-23 Y. Alhassid , G. F. Bertsch , D. J. Dean , S. E. Koonin

While the shell model Monte Carlo approach has been successful in the microscopic calculation of nuclear state densities, it has been difficult to calculate accurately state densities of odd-even heavy nuclei. This is because the projection…

Nuclear Theory · Physics 2013-04-30 C. Özen , Y. Alhassid , H. Nakada

A mean-field plus pairing model for atomic nuclei in the Fe region was studied using a finite-temperature quantum Monte-Carlo method. We present results for thermodynamical quantities such as the internal energy and the specific heat. These…

Nuclear Theory · Physics 2008-11-26 S. Rombouts , K. Heyde , N. Jachowicz

Auxiliary-field quantum Monte Carlo methods enable the calculation of thermal and ground state properties of correlated quantum many-body systems in model spaces that are many orders of magnitude larger than those that can be treated by…

Nuclear Theory · Physics 2019-07-29 Y. Alhassid

The microscopic description of collectivity in heavy nuclei in the framework of the configuration-interaction shell model has been a major challenge. The size of the model space required for the description of heavy nuclei prohibits the use…

Nuclear Theory · Physics 2015-06-18 C. Özen , Y. Alhassid , H. Nakada

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 mean-field approximation predicts pairing and shape phase transitions in nuclei as a function of temperature or excitation energy. However, in the finite nucleus the singularities of these phase transitions are smoothed out by quantal…

Nuclear Theory · Physics 2015-06-11 Y. Alhassid , C. Özen , H. Nakada

Rigorous statistical methods for estimating thermonuclear reaction rates and nucleosynthesis are becoming increasingly established in nuclear astrophysics. The main challenge being faced is that experimental reaction rates are highly…

Nuclear Experiment · Physics 2015-06-22 Christian Iliadis , Richard Longland , Alain Coc , F. X. Timmes , Art E. Champagne

We present a novel quantum Monte Carlo method based on a path integral in Fock space, which allows to compute finite-temperature properties of a many-body nuclear system with a monopole pairing interaction in the canonical ensemble. It…

Nuclear Theory · Physics 2009-01-23 N. J. Cerf

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

We investigate the statistical properties of 56-57Fe within a model capable of treating all the nucleons as active in an infinite model space including pairing effects. Working within the canonical ensemble, our model is built on…

Nuclear Theory · Physics 2018-07-18 Bassam Shehadeh , James P. Vary

A method based on Monte Carlo techniques is presented for evaluating thermonuclear reaction rates. We begin by reviewing commonly applied procedures and point out that reaction rates that have been reported up to now in the literature have…

Solar and Stellar Astrophysics · Physics 2015-05-18 Richard Longland , Christian Iliadis , Art Champagne , Joe Newton , Claudio Ugalde , Alain Coc , Ryan Fitzgerald

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

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

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 nuclear shell model is known to describe the properties of various nuclei extremely well. However, the auxiliary-field quantum Monte Carlo calculations cannot be applied to it with general interactions due to the sign problem. The model…

Nuclear Theory · Physics 2025-08-22 Yuhma Asano , Yuta Ito , Jun Nishimura , Noritaka Shimizu

We report on the development of a new shell-model Monte Carlo algorithm which uses the proton-neutron formalism. Shell model Monte Carlo methods, within the isospin formulation, have been successfully used in large-scale shell-model…

Nuclear Theory · Physics 2015-06-26 C. Ozen , D. J. Dean

We utilize the Shell Model Monte Carlo (SMMC) method to study the structure of rare earth nuclei. This work demonstrates the first systematic ``full oscillator shell plus intruder'' calculations in such heavy nuclei. Exact solutions of a…

Nuclear Theory · Physics 2009-10-31 J. A. White , S. E. Koonin , D. J. Dean