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Nuclear Theory·nucl-th

Tuesday·December 7, 2021

18 papers—5 primary·13 cross-listed

All18Primary5Cross-lists13
  1. 01

    Machine Learning in Nuclear Physics

    Amber Boehnlein🇺🇸 · Markus Diefenthaler🇺🇸 · Cristiano Fanelli🇺🇸 · Morten Hjorth-Jensen🇺🇸 · Tanja Horn🇺🇸 · Michelle P. Kuchera🇺🇸 · Dean Lee🇺🇸 · Witold Nazarewicz🇺🇸 · Kostas Orginos🇺🇸 · Peter Ostroumov🇺🇸 · Long-Gang Pang🇺🇸 · Alan Poon🇺🇸 and 6 other authors

    Advances in machine learning methods provide tools that have broad applicability in scientific research. These techniques are being applied across the diversity of nuclear physics research topics, leading to advances that will facilitate scientific discoveries and societal applications. This Review gives a snapshot of nuclear physics research which has been transformed by machine learning techniques.

    nucl-thcs.LGhep-exnucl-exRMP(2022)·252 citations
  2. 02

    Nuclear potentials relevant to the symmetry energy in chiral models

    Niu Li🇨🇳 · Si-Na Wei🇨🇳 · Wei-Zhou Jiang🇨🇳

    We employ the extended Nambu-Jona-Lasinio, linear- models, and the density-dependent model with chiral limits to work out the mean fields and relevant properties of nuclear matter. To have the constraint from the data, we reexamine the Dirac optical potentials and symmetry potential based on the relativistic impulse approximation (RIA). Unlike the extended NJL and the density-dependent models with the chiral limit in terms of the vanishing scalar density, the extended linear- model with a sluggish changing scalar field loses the chiral limit at the high density end. The various scalar fields can characterize the different Schrödinger-equivalent potentials and kinetic symmetry energy in the whole density region and the symmetry potential in the intermediate density region. The drop of the scalar field due to the chiral restoration results in a clear rise of the kinetic symmetry energy. The chiral limit in the models gives rise to the softening of the symmetry potential and thereof the symmetry energy at high densities.

    nucl-thSymmetry(2022)·3 citations
  3. 03

    Ab initio nucleon-nucleus elastic scattering with chiral effective field theory uncertainties

    R. B. Baker · B. McClung · Ch. Elster · P. Maris · S. P. Weppner · M. Burrows · G. Popa

    Background: Effective interactions for nucleon-nucleus () elastic scattering from first principles require the use of the same nucleon-nucleon () interaction in the structure and reaction calculations, and a consistent treatment of the relevant operators at each order. Purpose: Truncation uncertainties of chiral forces have been studied for scattering observables in few-body systems and for bound state properties of light nuclei. We extend this to elastic scattering. Methods: With the spectator expansion of multiple scattering theory and the no-core shell model, we use a chiral interaction from the LENPIC collaboration to consistently calculate the leading order effective interaction up to third chiral order (N2LO) and extract elastic scattering observables. We quantify the chiral truncation error using pointwise and correlated methods. Results: We analyze proton-O and neutron-C elastic scattering observables between 65 and 185 MeV projectile kinetic energy. We find qualitatively similar results for the chiral truncation uncertainties as in few-body systems, which we assess using similar diagnostic tools. The order-by-order convergence of the scattering observables for O and C is reasonable near 100 MeV, but for higher energies the expansion parameter becomes too large to converge. We find a near-perfect correlation between the neutron differential cross section and the Wolfenstein amplitudes for small momentum transfers. Conclusions: The tools used to study the convergence of a chiral interaction in few-body systems can be applied to scattering with minor changes. The interaction used here gives a good description of O and C scattering observables as low as 65 MeV. The very forward direction of the neutron differential cross section mirrors the behavior of the interaction amazingly well.

    nucl-thnucl-exPRC(2022)·11 citations
  4. 04

    The roles of three-nucleon force and continuum coupling in mirror symmetry breaking of oxygen mass region

    S. Zhang · Y. Z. Ma · J. G. Li · B. S. Hu · Q. Yuan · Z. H. Cheng · F. R. Xu

    With both three-nucleon force and continuum coupling included, we have developed a self-consistent {\it ab initio} Gamow shell model within the Gamow Hartree-Fock (GHF) basis obtained by the realistic interaction itself. With the chiral two-nucleon NLO and three-nucleon NLO interactions, the Gamow shell model has been applied to the mirror systems of neutron-rich isotopes and proton-rich isotones, giving good agreements with data in binding energies, dripline positions and excitation spectra. The GHF calculated that the , and orbitals are resonances. The resonance states and their interplay with nonresonant continua play a crucial role in the descriptions of nuclei around driplines. Excitation spectra and Thomas-Ehrman shifts observed can be better described when both three-nucleon force and continuum coupling are considered in calculations. The three-nucleon force and continuum coupling produce a combined effect on the Thomas-Ehrman shift, e.g., for the resonance level of Na. The calculations help the understandings of related nuclear astrophysical processes.

    nucl-thPLB(2022)·40 citations
  5. 05

    Octet and decuplet baryon -terms and mass decompositions

    P. M. Copeland🇺🇸 · Chueng-Ryong Ji🇺🇸 · W. Melnitchouk🇺🇸

    We present a comprehensive analysis of the SU(3) octet and decuplet baryon masses and -terms using high-precision lattice QCD data and chiral SU(3) effective theory with finite range regularization. The effects of various systematic uncertainties, including from the scale setting of the lattice data and the regularization prescriptions, are quantified. We find the pion-nucleon and strange nucleon -terms to be MeV and MeV, respectively. The results provide constraints on the energy-momentum tensor mass decompositions of the SU(3) octet and decuplet baryons, where we find the trace anomaly and quark/gluon energies decrease for strange baryons due to their larger strange -terms.

    nucl-thhep-lathep-phPRD(2023)·10 citations

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first authorsco-authorsvia INSPIRE