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Nuclear Theory·nucl-th

Monday·April 29, 2019

10 papers—4 primary·6 cross-listed

All10Primary4Cross-lists6
  1. 01

    Tetraneutron condensation in neutron rich matter

    O. Ivanytskyi🇪🇸 · M. Ángeles Pérez-García🇪🇸 · C. Albertus🇪🇸

    In this work we investigate the possible condensation of tetraneutron resonant states in the lower density neutron rich gas regions inside Neutron Stars (NSs). Using a relativistic density functional approach we characterize the system containing different hadronic species including, besides tetraneutrons, nucleons and a set of light clusters (He, particles, deuterium and tritium). and mesonic fields provide the interaction in the nuclear system. We study how the tetraneutron presence could significantly impact the nucleon pairing fractions and the distribution of baryonic charge among species. For this we assume that they can be thermodynamically produced in an equilibrated medium and scan a range of coupling strengths to the mesonic fields from prescriptions based on isospin symmetry arguments. We find that tetraneutrons may appear over a range of densities belonging to the outer NS crust carrying a sizable amount of baryonic charge thus depleting the nucleon pairing fractions.

    nucl-thastro-ph.HEEPJA(2019)·13 citations
  2. 02

    Exact isovector pairing in a shell-model framework: Role of proton-neutron correlations in isobaric analog states

    M. E. Miora · K. D. Launey · D. Kekejian · F. Pan · J. P. Draayer

    We utilize a nuclear shell model Hamiltonian with only two adjustable parameters to generate, for the first time, exact solutions for pairing correlations for light to medium-mass nuclei, including the challenging proton-neutron pairs, while also identifying the primary physics involved. In addition to single-particle energy and Coulomb potential terms, the shell model Hamiltonian consists of an isovector pairing interaction and an average proton-neutron isoscalar interaction, where the term describes the average interaction between non-paired protons and neutrons. This Hamiltonian is exactly solvable, where, utilizing 3 to 7 single-particle energy levels, we reproduce experimental data for 0 state energies for isotopes with mass through exceptionally well including isotopes from He to Ge. Additionally, we isolate effects due to like-particle and proton-neutron pairing, provide estimates for the total and proton-neutron pairing gaps, and reproduce (neutron) = (proton) irregularity. These results provide a further understanding for the key role of proton-neutron pairing correlations in nuclei, which is especially important for waiting-point nuclei on the rp-path of nucleosynthesis.

    nucl-thPRC(2019)·8 citations
  3. 03

    The many-nucleon unified model and the dynamics of nuclear rotations

    David J. Rowe

    It is determined that a many-nucleon version of the Bohr-Mottelson unified model that contains the essential observables of that model and has irreducible representations that span the Hilbert space of fully anti-symmetric states of nuclei, is given uniquely by the symplectic model. This model is shown to provide a framework for an examination of the dynamics of nuclear rotations. A first discovery is that rotational energies are mixtures of potential and kinetic energies even in an adiabatic limit.

    nucl-thquant-ph0 citations
  4. 04

    Landau and Eckart frames for relativistic fluids in nuclear collisions

    Akihiko Monnai🇯🇵

    The quark matter created in relativistic nuclear collisions is interpreted as a nearly-perfect fluid. The recent efforts to explore its finite-density properties in the beam energy scan programs motivate one to revisit the issue of the local rest frame fixing in off-equilibrium hydrodynamics. I first investigate full second-order relativistic hydrodynamics in the Landau and the Eckart frames. Then numerical hydrodynamic simulations are performed to elucidate the effect of frame choice on flow observables in relativistic nuclear collisions. The results indicate that the flow can differ in the Landau and the Eckart frames but charged particle and net baryon rapidity distributions are mostly frame independent when off-equilibrium kinetic freeze-out is considered.

    nucl-thhep-phnucl-exPRC(2019)·23 citations

Affiliations

first authorsco-authorsvia INSPIRE