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Related papers: Electromagnetic Strength Distributions from the Ab…

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In the present work, we have done a comprehensive study of low-lying energy spectrum for oxygen and fluorine chains using $ab~initio$ no core shell model. We have used inside nonlocal outside Yukawa (INOY) potential, which is a two body…

Nuclear Theory · Physics 2020-04-14 Archana Saxena , Praveen C. Srivastava

A realistic shell-model study is performed for neutron-deficient tin isotopes up to mass A=108. All shell-model ingredients, namely two-body matrix elements, single-particle energies, and effective charges for electric quadrupole transition…

Nuclear Theory · Physics 2015-06-23 L. Coraggio , A. Covello , A. Gargano , N. Itaco , T. T. S. Kuo

In this work we use matrix models to study the problem of strength distributions. This is motivated by noticing near exponential fall offs of strengths in calculated magnetic dipole excitations. We emphasize that the quality of the…

Nuclear Theory · Physics 2021-04-27 Larry Zamick , Arun Kingan

The isoscalar giant monopole, dipole, and quadrupole strength distributions have been deduced in $^{90, 92}$Zr, and $^{92}$Mo from "background-free" spectra of inelastic $\alpha$-particle scattering at a beam energy of 385 MeV at extremely…

Large-space no-core shell model calculations have been performed for A=3-6 nuclei, using a starting-energy-independent two-body effective interaction derived by application of the Lee-Suzuki similarity transformation. This transformation…

Nuclear Theory · Physics 2008-11-26 P. Navratil , B. R. Barrett

We present a detailed discussion of the structure of the low-lying positive-parity energy spectrum of $^{12}$C from a no-core shell-model perspective. The approach utilizes a fraction of the usual shell-model space and extends its…

Nuclear Theory · Physics 2017-04-19 A. C. Dreyfuss , K. D. Launey , T. Dytrych , J. P. Draayer , R. B. Baker , C. M. Deibel , C. Bahri

Working in the framework of the ab-initio no-core shell model, we derive two-body effective interactions microscopically for specific harmonic-oscillator basis spaces from the realistic Argonne V8' nucleon-nucleon potential. However, our…

Nuclear Theory · Physics 2007-05-23 M. S. Fayache , J. P. Vary , B. R. Barrett , P. Navratil , S. Aroua

We explore the systematics of ground-state and excitation energies in singly-strange hypernuclei throughout the helium and lithium isotopic chains --- from $^5_\Lambda$He to $^{11}_\Lambda$He and from $^7_\Lambda$Li to $^{12}_\Lambda$Li ---…

Nuclear Theory · Physics 2018-03-01 Roland Wirth , Robert Roth

We have performed shell-model calculations for the nucleus $^{137}$Xe, which was recently studied experimentally using the $^{136}$Xe($d,p$) reaction in inverse kinematics. The main aim of our study has been to investigate the…

Nuclear Theory · Physics 2015-06-12 L. Coraggio , A. Covello , A. Gargano , N. Itaco

The ab initio no-core shell model (NCSM) is extended to include a realistic three-body interaction in calculations for p-shell nuclei. The NCSM formalism is reviewed and new features needed in calculations with three-body forces are…

Nuclear Theory · Physics 2009-11-10 P. Navratil , W. E. Ormand

No-Core Gamow Shell Model (NCGSM) is applied for the first time to study selected well-bound and unbound states of helium isotopes. This model is formulated on the complex energy plane and, by using a complete Berggren ensemble, treats…

Nuclear Theory · Physics 2015-06-12 G. Papadimitriou , J. Rotureau , N. Michel , M. Płoszajczak , B. R. Barrett

Ab initio calculations have achieved remarkable success in nuclear structure studies. Numerous works highlight the pivotal role of three-body forces in nuclear ab initio calculations. Concurrently, efforts have been made to replicate these…

Nuclear Theory · Physics 2024-06-13 P. Y. Wang , J. G. Li , S. Zhang , Q. Yuan , M. R. Xie , W. Zuo

We present an overview of recent results and developments of the no-core shell model (NCSM), an ab initio approach to the nuclear many-body problem for light nuclei. In this approach, we start from realistic two-nucleon or two- plus…

Nuclear Theory · Physics 2009-06-19 Petr Navratil , Sofia Quaglioni , Ionel Stetcu , Bruce R. Barrett

We present a new approach to the construction of effective interactions suitable for many-body calculations by means of the no-core shell model (NCSM). We consider an effective field theory (EFT) with only nucleon fields directly in the…

Nuclear Theory · Physics 2008-11-26 I. Stetcu , B. R. Barrett , U. van Kolck

Constructing microscopic effective interactions (`optical potentials') for nucleon-nucleus (NA) elastic scattering requires in first order off-shell nucleon-nucleon (NN) scattering amplitudes between the projectile and the struck target…

Nuclear Theory · Physics 2019-10-03 G. Popa , M. Burrows , Ch. Elster , K. D. Launey , P. Maris , S. P. Weppner

We present a microscopic description of nuclei in an intermediate-mass region, including the proximity to the proton drip line, based on a no-core shell model with a schematic many-nucleon long-range interaction with no parameter…

Nuclear Theory · Physics 2015-06-17 G. K. Tobin , M. C. Ferriss , K. D. Launey , T. Dytrych , J. P. Draayer , A. C. Dreyfuss , C. Bahri

Novel equations for the electric dipole polarizability $\alpha_{_{E1}}$ of low-lying excited states in atomic nuclei -- and the related $(-2)$ moment of the total photo-absorption cross section, $\sigma_{_{-2}}$ -- are inferred in terms of…

Nuclear Theory · Physics 2024-03-12 José Nicolás Orce , Cebo Ngwetsheni

We introduce a hybrid many-body approach that combines the flexibility of the No-Core Shell Model (NCSM) with the efficiency of Multi-Configurational Perturbation Theory (MCPT) to compute ground- and excited-state energies in arbitrary…

Nuclear Theory · Physics 2018-10-24 Alexander Tichai , Eskendr Gebrerufael , Klaus Vobig , Robert Roth

Nuclear structure and reaction theory are undergoing a major renaissance with advances in many-body methods, strong interactions with greatly improved links to Quantum Chromodynamics (QCD), the advent of high performance computing, and…

Nuclear Theory · Physics 2019-01-30 James P. Vary , Pieter Maris , Patrick J. Fasano , Mark A. Caprio

Radiative strength functions (RSFs) model the bulk electromagnetic response of highly-excited nuclei and are critical inputs for statistical reaction codes. In this paper, we present a definition of the RSF that is consistent with…

Nuclear Theory · Physics 2026-04-30 Oliver C. Gorton , Konstantinos Kravvaris , Jutta E. Escher , Calvin W. Johnson