PaperPanorama
FAQ

Nuclear Theory·nucl-th

Tuesday·September 22, 2020

9 papers—5 primary·4 cross-listed

All9Primary5Cross-lists4
  1. 01

    SU(3)-guided Realistic Nucleon-nucleon Interactions for Large-scale Calculations

    G. H. Sargsyan · K. D. Launey · R. B. Baker · T. Dytrych · J. P. Draayer

    We examine nucleon-nucleon realistic interactions, based on their SU(3) decomposition to SU(3)-symmetric components. We find that many of these interaction components are negligible, which, in turn, allows us to identify a subset of physically relevant components that are sufficient to describe the structure of low-lying states in C and related observables, such as excitation energies, electric quadrupole transitions and rms radii. We find that paring the interaction down to half of the SU(3)-symmetric components or more yields results that practically coincide with the corresponding ab initio calculations with the full interaction. In addition, we show that while various realistic interactions differ in their SU(3) decomposition, their renormalized effective counterparts exhibit a striking similarity and composition that can be linked to dominant nuclear features such as deformation, pairing, clustering, and spin-orbit effect.

    nucl-thPRC(2021)·6 citations
  2. 02

    Dichotomy of Baryons as Quantum Hall Droplets and Skyrmions In Compact-Star Matter

    Yong-Liang Ma🇨🇳 · Mannque Rho🇫🇷

    We review the recent exploration of a possible "domain-wall structure" of compressed baryonic matter in massive compact stars in terms of fractional quantum Hall droplets and skyrmions for baryons in medium. The theoretical framework is anchored on an effective nuclear effective field theory that incorporates two hidden symmetries, flavor local symmetry and scale symmetry conjectured to be dual to the gluons and quarks of QCD. It hints at a basically different, hitherto undiscovered structure of nuclear matter at low as well as high densities. Hidden "genuine dilaton (GD)" symmetry and hidden local symmetry (HLS) gauge-equivalent at low density to nonlinear sigma model capturing chiral symmetry, put together in nuclear effective field theory, are seen to play an increasingly important role in providing hadron-quark duality in baryonic matter. This strongly motivates incorporating both symmetries in formulating "first-principles" approaches to nuclear dynamics encompassing from the nuclear matter density to the highest density stable in the Universe.

    nucl-thastro-ph.HEhep-phSymmetry(2021)·28 citations
  3. 03

    Coupled-channel treatment of in effective field theory

    Renato Higa🇧🇷 · Pradeepa Premarathna🇺🇸 · Gautam Rupak🇺🇸

    The E1 contribution to the capture reaction is calculated at low energies. We employ a coupled-channel formalism to account for the excited core contribution. We develop a halo effective field theory power counting where capture in the spin channel is enhanced over the channel. A next-to-leading order calculation is presented where the excited core contribution is shown to affect only the overall normalization of the cross section. The momentum dependence of the capture cross section, as a consequence, is the same in a theory with or without the excited degree of freedom at this order of the calculation. The kinematical signature of the core is negligible at momenta below 1 MeV and significant only beyond the resonance energy, though still compatible with a next-to-next-to-leading order correction. We compare our formalism with a previous halo effective field theory calculation [Zhang, Nollett, and Phillips, Phys. Rev. C 89, 024613 (2014)] that also treated the core as an explicit degree of freedom. Our formal expressions and analysis disagree with this earlier work in several aspects.

    nucl-thastro-ph.SRnucl-exEPJA(2021)·7 citations
  4. 04

    Collectivity in large and small systems formed in ultrarelativistic collisions

    Rajeev S Bhalerao🇮🇳

    Collective flow of the final-state hadrons observed in ultrarelativistic heavy-ion collisions or even in smaller systems formed in high-multiplicity pp and p/d/He-nucleus collisions is one of the most important diagnostic tools to probe the initial state of the system and to shed light on the properties of the short-lived, strongly-interacting many-body state formed in these collisions. Limited, in the initial years, to the study of mainly the directed and elliptic flows -- the first two Fourier harmonics of the single-particle azimuthal distribution -- this field has evolved in recent years into a much richer area of activity. This includes not only higher Fourier harmonics and multiparticle cumulants, but also a variety of other related observables, such as the ridge seen in two-particle correlations, flow decorrelation, symmetric cumulants and event-plane correlators which measure correlations between the magnitudes or phases of the complex flows in different harmonics, coefficients that measure the nonlinear hydrodynamic response, statistical properties, such as the non-Gaussianity of the flow fluctuations, etc. We present a Tutorial Review of the modern flow picture and the various aspects of the collectivity -- an emergent phenomenon in quantum chromodynamics.

    nucl-thhep-phnucl-exEur.Phys.J.ST(2021)·19 citations
  5. 05

    Quadrupole dominance in the light Sn and in the Cd isotopes

    A. P. Zuker🇫🇷

    [Background] The BE2 rates of the Sn isotopes for exhibit enhancements hitherto unexplained. The same is true for the Cd isotopes. [Purpose] Describe the electromagnetic properties of the Sn and Cd isotopes [Method] Shell model calculations with a minimally renormalized realistic interaction, supplemented by Quasi and Pseudo-SU3 symmetries and Nilsson-SU3 selfconsistent calculations. [Results for ] Shell model calculations with the neutron effective charge as single free parameter describe well the BE2(2>0) and BE2(4>2) rates for in the Cd and Sn isotopes. The former exhibit weak permanent deformation corroborating the prediction of a Pseudo-SU3 symmetry, which remains of heuristic value in the latter, where the pairing force erodes the quadrupole dominance. Calculations in and -dimensional spaces exhibit almost identical patterns: A vindication of the shell model. [Results for ] Nilsson-SU3 calculations describe BE2 patterns in [112-120]Cd and [116-118]Sn isotopes having sizable quadrupole moment of non-rotational origin denoted as q-vibrations. No calculations are proposed for the heavier species, for which the conventional seniority dscription is assumed for Sn, while in Cd the quadrupole moments change sign. [Conclusion] A radical reexamination of traditional interpretations in the region has been shown to be necessary, in which quadrupole dominance plays a major role. What emerges is a bumpy but coherent view.

    nucl-thPRC(2021)·22 citations

Affiliations

first authorsco-authorsvia INSPIRE