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Nuclear Theory·nucl-th

Monday·February 14, 2022

6 papers—4 primary·2 cross-listed

All6Primary4Cross-lists2
  1. 01

    Algebraic approach to quarkyoniclike configuration and stable diquarks in dense matter

    Aaron Park🇰🇷 · Su Houng Lee🇰🇷

    We study the color-spin interaction energy of a quark, a diquark and a baryon with their surrounding baryons and/or quark matter. This is accomplished by classifying all possible flavor and spin states of the resulting multiquark configuration in both the flavor SU(2) and SU(3) symmetric cases. We find that while the baryon has the lowest interaction energy when there is only a single surrounding baryon, the quark has the lowest interaction energy when the surrounding has more than three baryons or becomes a quark gas. As the short range nucleon-nucleon interactions are dominated by the color-spin interactions, our finding suggests that the baryon modes near other baryons are suppressed due to larger repulsive energy compared to that of a quark and thus provides a quark model basis for the quarkyoniclike phase in dense matter. At the same time, when the internal interactions are taken into account, and the matter density is high so that the color-spin interaction becomes the dominant interaction, the diquark becomes the lowest energy configuration and will thus appear in both the dense baryonic and/or quark matter.

    nucl-thhep-phPRD(2022)·4 citations
  2. 02

    Pasta phases in neutron stars under strong magnetic fields

    Xiaopeng Wang · Jing Li · Jianjun Fang · Helena Pais · Constança Providência

    In the present work, we consider nuclear matter in the innermost crust of neutron stars under the presence of a strong magnetic field within the framework of a relativistic mean-field description. Two models with a different slope of the symmetry energy are considered in order to discuss the density-dependence of the equation of state on the crust structure. The non-homogeneous matter in -equilibrium is described within the coexisting phases method, and the effect of including the anomalous magnetic moment is discussed. Five different geometries for the pasta structures are considered. It is shown that strong magnetic fields cause an extension of the inner crust of the neutron stars, with the occurrence of a series of disconnected non-homogeneous matter regions above the one existing for a null magnetic field. Moreover, we observed that in these disconnected regions, for some values of the magnetic field, all five different cluster geometrical shapes occur, and the gas density is close to the cluster density. Also, the pressure at the neutron star crust-core transition much larger than the pressure obtained for a zero magnetic field. Another noticeable effect of the presence of strong magnetic fields is the increase of the proton fraction, favoring the appearance of protons in the gas background.

    nucl-thastro-ph.HEPRD(2022)·13 citations
  3. 03

    Expected yields of Ta (e,e') Ta in the multi-keV range with a plasma-cathode electron beam

    F.Gobet🇫🇷 · A.Ya.Dzyublik🇺🇦 · G.Gosselin🇫🇷 · V.Méot🇫🇷 · M.Versteegen🇫🇷

    Calculations of the cross sections of inelastic electron scattering on a nucleus in the multi-keV energy range strongly depend on the description of the screening of the nuclear Coulomb potential as well as on the deformation of the wave functions of the incoming and outgoing electron in the vicinity of the nucleus. These cross sections are evaluated at values lower than cm which vary by several orders of magnitude according to the models. Experimental measurements would be required to constrain the models but it is a real challenge to measure such low cross sections. In this study, we demonstrate that inelastic electron scattering is the main nuclear excitation mechanism in a Ta target irradiated with a new intense 10 - 30 keV electron beam produced with a biased laser-plasma. Calculations show that through the detection of conversion electrons, it should be possible to measure the nuclear excitation yields. The effect of electron beam heating and of plasma deposition on the tantalum target are quantified, thus allowing the dimensioning of a possible experimental configuration to study processes in this range of energy for the first time.

    nucl-thnucl-exphysics.atom-phphysics.plasm-phPRC(2022)·2 citations
  4. 04

    Transport coefficients of magnetized neutron star cores

    Peter Shternin · Dmitry Ofengeim

    We review the calculations of the kinetic coefficients (thermal conductivity, shear viscosity, momentum transfer rates) of the neutron star core matter within the framework of the Landau Fermi-liquid theory. We restrict ourselves to the case of normal (i.e. non-superfluid) matter. As an example we consider simplest composition of neutron star core matter. Utilizing the CompOSE database of dense matter equations of state and several microscopic interactions we analyze the uncertainties in calculations of the kinetic coefficients that result from the insufficient knowledge of the properties of the dense nuclear matter and suggest possible approximate treatment. In our study we also take into account non-quantizing magnetic field. The presence of magnetic field makes transport anisotropic leading to the tensor structure of kinetic coefficients. We find that the moderate ( G) magnetic field do not affect considerably thermal conductivity of neutron star core matter, since the latter is mainly governed by the electrically neutral neutrons. In contrast, shear viscosity is affected even by the moderate G. Based on the in-vacuum nucleon interactions we provide practical expressions for calculation of transport coefficients for any equation of state of dense matter.

    nucl-thastro-ph.HEEPJA(2022)·8 citations
  5. 05

    Resummed lattice QCD equation of state at finite baryon density: strangeness neutrality and beyond

    Szabolcs Borsanyi🇩🇪 · Zoltan Fodor🇩🇪 · Jana N. Guenther🇩🇪 · Ruben Kara🇺🇸 · Paolo Parotto🇺🇸 · Attila Pasztor🇭🇺 · Claudia Ratti🇺🇸 · Kalman K. Szabo🇩🇪

    We calculate a resummed equation of state with lattice QCD simulations at imaginary chemical potentials. This work presents a generalization of the scheme introduced in 2102.06660 to the case of non-zero , focusing on the line of strangeness neutrality. We present results up to on the strangeness neutral line in the temperature range . We also extrapolate the finite baryon density equation of state to small non-zero values of the strangeness-to-baryon ratio . We perform a continuum extrapolation using lattice simulations of the 4stout-improved staggered action with 8, 10, 12 and 16 timeslices.

    ↳ hep-lathep-phnucl-thPRD(2022)·69 citations
  6. 06

    Longitudinal dynamics for mesons on the light cone

    Yang Li🇨🇳 · James P. Vary🇺🇸

    We survey a set of proposed light-front models for confinement in the valence quark sector of the mesons and portray similarities as well as differences. We present the spectroscopies for the light mesons that result from a selection of longitudinal confinement forms. We note that the Sturm-Liouville theory provides a unifying framework for many elements of this comparison.

    ↳ hep-phnucl-thPRD(2022)·14 citations

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first authorsco-authorsvia INSPIRE