PaperPanorama

Nuclear Theory·nucl-th

Monday·April 25, 2022

6 papers4 primary·2 cross-listed

  1. 01

    Path Integral Quantum Monte Carlo Calculations of Light Nuclei

    Rong Chen · Kevin E. Schmidt

    We describe a path-integral ground-state quantum Monte Carlo method for light nuclei in continuous space. We show how to efficiently update and sample the paths with spin-isospin dependent and spin-orbit interactions. We apply the method to the triton and alpha particle using both local chiral interactions with next-to-next-to-leading-order %(NLO) and the Argonne interactions. For operators, like the total energy, that commute with the Hamiltonian, our results agree with Green's function Monte Carlo and auxiliary field diffusion Monte Carlo calculations. For operators that do not commute with the Hamiltonian and for Euclidean response functions, the path-integral formulation allows straightforward calculation without forward walking or the increased variance typical of diffusion methods. We demonstrate this by calculating density distributions, root mean square radii, and Euclidean response functions for single-nucleon couplings.

    nucl-thPRC(2022)·3 citations
  2. 02

    Extraction of different temperatures and kinetic freeze-out volume in high energy collisions

    M. Waqas🇨🇳 · G.-X. Peng🇨🇳 · M. Ajaz🇵🇰 · A. Haj Ismail🇮🇳 · Z. Wazir🇵🇰 · L.-L. Li🇨🇳

    We analyze the transverse momentum () spectra, [(1/2) /], of kaon, proton, deuteron and triton in different centrality events in gold-gold (Au-Au) collisions at Relativistic Heavy Ion Collisions (RHIC) by Hagedorn thermal model and extracted the excitation function of effective temperature, kinetic freeze-out volume, initial temperature and kinetic freeze-out temperature. We perceived that the effective temperature, initial temperature and kinetic freeze-out temperature sharply increases from 7.7 GeV to 14.5 GeV and then remain static from 14.5-39 GeV, and this consistency may disclose that the onset energy of the phase transition of partial deconfinement and the whole deconfinement are 14.5 and 39 GeV respectively. The kinetic freeze-out volume and mean transverse momentum grows with the rise of collision energy. Furthermore, the different extracted temperatures are observed in the order of time evolution of the interacting system, and they (as well as kinetic freeze-out volume) have an increasing trend from peripheral to central collisions. We also observed the mass dependence of the effective temperature and kinetic freeze-out volume where former increases while the later decreases for heavier particles, which indicates the early freeze-out of the heavier particles.

    nucl-thhep-phJ.Phys.G(2022)·21 citations
  3. 03

    Nuclear spectra from low-energy interactions

    J. Ljungberg · B. G. Carlsson · J. Rotureau · A. Idini · I. Ragnarsson

    A method to describe spectra starting from nuclear density functionals is explored. The idea is based on postulating an effective Hamiltonian that reproduces the stiffness associated with collective modes. The method defines a simple form of such an effective Hamiltonian and a mapping to go from a density functional to the corresponding Hamiltonian. In order to test the method, the Hamiltonian is constrained using a Skyrme functional and solved with the generator-coordinate method to describe low-lying levels and electromagnetic transitions in Cr and Mg.

    nucl-thPRC(2022)·9 citations
  4. 04

    Energy Dependent Model of Isotopic Production Cross Sections from Proton-O Interactions

    Francis A. Cucinotta · Sungmin Pak

    Proton interactions with O nuclei are the most frequent nuclear interaction leading to secondary radiation in tissues for space radiation and cancer therapy with protons. In addition, O has the largest fluence of galactic cosmic rays, and interacts with hydrogen in tissue or water and polyethylene shielding. The fragmentation of oxygen produces a large number of heavy ion (A>4) target fragments (TF) with high ionization density. Here we develop an analytical model of energy dependent proton-O cross sections. We introduce corrections to measurements of total charge changing cross sections to extend data on nuclear absorption cross sections. Using experimental data and a 2nd order optical model an accurate formula for the p-O absorption cross section from <10 MeV/n to >10 GeV/N is obtained. The energy dependence of the isotopic cross sections is modeled as multiplicities scaled to absorption cross section resulting in an accurate model over the full energy range.

    nucl-th0 citations

Affiliations

first authorsco-authorsvia INSPIRE