Nuclear Theory·nucl-th

Thursday·April 11, 2019

7 papers—3 primary·4 cross-listed

04
[Submitted on 10 Apr 2019] (cross-list from astro-ph.HE)
Role of Landau-Rabi quantization of electron motion on the crust of magnetars within the nuclear energy density functional theory
Y. D. Mutafchieva · N. Chamel · Zh. K. Stoyanov · J. M. Pearson · L. M. Mihailov
Magnetic fields of order $1 0^{15}$ G have been measured at the surface of some neutron stars, and much stronger magnetic fields are expected to be present in the solid region beneath the surface. The effects of the magnetic field on the equation of state and on the composition of the crust due to Landau-Rabi quantization of electron motion are studied. Both the outer and inner crustal regions are described in a unified and consistent way within the nuclear-energy density functional theory.
Comments:
23 pages, 11 figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
1904.05045 [pdf]
PRC(2019)·20 citations
05
[Submitted on 10 Apr 2019] (cross-list from astro-ph.HE)
Delineating the properties of matter in cold, dense QCD
Toru Kojo🇨🇳
The properties of dense QCD matter are delineated through the construction of equations of state which should be consistent with QCD calculations in the low and high density limits, nuclear laboratory experiments, and the neutron star observations. These constraints, together with the causality condition of the sound velocity, are used to develop the picture of hadron-quark continuity in which hadronic matter continuously transforms into quark matter (modulo small 1st order phase transitions). For hadronic matter (at baryon density nB > ~2n0 with n0 ~ 0.16 fm^(-3) being the nuclear saturation density) we use equations of state by Togashi et al. based on microscopic variational many-body calculations, and for quark matter (nB > ~5n0) we construct equations of state using a schematic quark model (with strangeness) whose interactions are motivated by the hadron phenomenology. The region between hadronic and quark matters (~2n0 < nB < ~5n0), which is most difficult to calculate, is treated by highly constrained interpolation between nuclear and quark matter equations of state. The resultant unified equation of state at zero temperature and beta-equilibrium, which we call Quark-Hadron-Crossover (QHC18 and QHC19), is consistent with the measured properties of neutron stars and in addition gives us microscopic insights into the properties of dense QCD matter. In particular to ~10n0 the gluons can remain as non-perturbative as in vacuum and the strangeness can be as abundant as up- and down-quarks at the core of two-solar mass neutron stars. Within our modeling the maximum mass is found less than ~2.35 times solar mass and the baryon density at the core ranges in ~5-8n0.
Comments:
18 pages 11 figures, AIP Proceedings of the Xiamen-CUSTIPEN Workshop on the EOS of Dense Neutron-Rich Matter in the Era of Gravitational Wave Astronomy, Jan. 3-7, Xiamen, China; v2 references are added
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1904.05080 [pdf]
AIP Conf.Proc.(2019)·13 citations
06
[Submitted on 10 Apr 2019] (cross-list from hep-ph)
Pomeron, nucleon-resonance, and $(0^{+}, 0^{-}, 1^{+})$ -meson contributions in $ϕ$ -meson photoproduction
Sang-Ho Kim🇰🇷 · Seung-il Nam🇰🇷
We investigate the reaction mechanism of the $ϕ$ -meson photoproduction off the proton target, i.e., $γ p \to ϕp$ , up to $s = 2.8$ GeV. For this purpose, we employ an effective Lagrangian approach in the tree-level Born approximation, and we employ various experimental and theoretical inputs. As a theoretical setup, the vectorlike Pomeron ( $C = + 1$ ) is taken into account as a parameterized two-gluon exchange contribution. We also consider $f_{1} (1285)$ axial-vector-meson, ( $π, η$ ) pseudoscalar-meson, and ( $a_{0}, f_{0}$ ) scalar-meson exchanges in the $t$ channel, in addition to the experimentally confirmed nucleon resonances, such as $N^{*} (2000, 5/ 2^{+})$ and $N^{*} (2300, 1/ 2^{+})$ , for the direct $ϕ$ -meson radiations in the $s$ and $u$ channels. We provide numerical results for the total and differential cross sections as well as the spin-density matrices in the Gottfried-Jackson, Adair, and helicity frames. We observe that, together with the universally accepted pomeron contribution, the considered meson and nucleon-resonance contributions play significant roles in reproducing the experimental data for the forward and backward $ϕ$ -meson scattering-angle regions, respectively, indicating the nontrivial interferences between mesonic and baryonic contributions.
Comments:
18 pages, 11 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1904.05133 [pdf]
PRC(2019)·12 citations
07
[Submitted on 10 Apr 2019] (cross-list from hep-ph)
Heavy Holographic Exotics: Tetraquarks as Efimov States
Yizhuang Liu🇨🇳 · Maciej A. Nowak🇵🇱 · Ismail Zahed🇺🇸
We provide a holographic description of non-strange multiquark exotics as compact topological molecules by binding heavy-light mesons to a tunneling configuration in D8-D $8 ˉ$ that is homotopic to the vacuum state with fixed Chern-Simons number. In the tunneling process, the heavy-light mesons transmute to fermions. Their binding is generic and arises from a trade-off between the dipole attraction induced by the Chern-Simons term and the U(1) fermionic repulsion. In the heavy quark limit, the open-flavor tetraquark exotics $QQ q ˉ q ˉ$ and $Q ˉ Q ˉ q q$ , emerge as bound Efimov states in a degenerate multiplet $I J^{π} = (0 0^{+}, 0 1^{+})$ with opposite intrinsic Chern-Simons numbers $\pm \frac{1}{2}$ . The hidden-flavor tetraquark exotics such as $Q Q ˉ q q ˉ$ , $QQ Q ˉ q ˉ$ and $QQ Q ˉ Q ˉ$ as compact topological molecules are unbound. Other exotics are also discussed.
Comments:
16 pages, 13 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
1904.05189 [pdf]
PRD(2019)·23 citations

Affiliations

first authorsco-authorsvia INSPIRE

Role of Landau-Rabi quantization of electron motion on the crust of magnetars within the nuclear energy density functional theory

Delineating the properties of matter in cold, dense QCD

Pomeron, nucleon-resonance, and (0+,0−,1+)-meson contributions in ϕ-meson photoproduction

Heavy Holographic Exotics: Tetraquarks as Efimov States

Affiliations

Pomeron, nucleon-resonance, and $(0^{+}, 0^{-}, 1^{+})$ -meson contributions in $ϕ$ -meson photoproduction