Nuclear Theory·nucl-th

Thursday·April 11, 2019

7 papers—3 primary·4 cross-listed

01
[Submitted on 10 Apr 2019]
Squeezed back-to-back correlations of bosons with nonzero widths in relativistic heavy-ion collisions
Peng-Zhi Xu🇨🇳 · Wei-Ning Zhang🇨🇳
We derive the formulas for calculating the squeezed back-to-back correlation (SBBC) between a boson and antiboson with nonzero width produced in relativistic heavy-ion collisions. The SBBCs of $D^{0}$ and $ϕ$ mesons with finite in-medium widths are studied. We find that the finite width can change the pattern of the SBBC function of $D^{0} D ˉ^{0}$ with respect to mass. However, the SBBC function of $ϕϕ$ is insensitive to the width. In the high-particle-momentum region, the SBBC function of $ϕϕ$ increases with particle momentum rapidly and can exceed that of $D^{0} D ˉ^{0}$ whether the width is nonzero or not.
Comments:
5 pages, 2 figures, accepted for publication in Phys. Rev. C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1904.04974 [pdf]
PRC(2019)·4 citations
02
[Submitted on 10 Apr 2019]
Towards an ab initio covariant density functional for nuclear structure
Shihang Shen🇨🇳 · Haozhao Liang🇯🇵 · Wen Hui Long🇨🇳 · Jie Meng🇯🇵 · Peter Ring🇨🇳
Nuclear structure models built from phenomenological mean fields, the effective nucleon-nucleon interactions (or Lagrangians), and the realistic bare nucleon-nucleon interactions are reviewed. The success of covariant density functional theory (CDFT) to describe nuclear properties and its influence on Brueckner theory within the relativistic framework are focused upon. The challenges and ambiguities of predictions for unstable nuclei without data or for high-density nuclear matter, arising from relativistic density functionals, are discussed. The basic ideas in building an ab initio relativistic density functional for nuclear structure from ab initio calculations with realistic nucleon-nucleon interactions for both nuclear matter and finite nuclei are presented. The current status of fully self-consistent relativistic Brueckner-Hartree-Fock (RBHF) calculations for finite nuclei or neutron drops (ideal systems composed of a finite number of neutrons and confined within an external field) is reviewed. The guidance and perspectives towards an ab initio covariant density functional theory for nuclear structure derived from the RBHF results are provided.
Comments:
67 pages, 26 figures, version accepted for publication in "Progress in Particleand Nuclear Physics"
Subjects:
Nuclear Theory (nucl-th); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics — Lattice (hep-lat)
arXiv:
1904.04977 [pdf]
PPNP(2019)·133 citations
03
[Submitted on 10 Apr 2019]
Role of consistent parameter sets in an assessment of the alpha-particle optical potential below the Coulomb barrier
V. Avrigeanu · M. Avrigeanu
Background: Further studies of high-precision measurements of alpha-induced reaction data below the Coulomb barrier have still raised questions about the alpha-particle optical model potential (OMP) within various mass ranges, i.e. for 64Zn, 108Cd, 113,115In, 121,123Sb, and 191,193Ir target nuclei. Purpose: The accuracy as well as eventual uncertainties and/or systematic errors of using a previous optical potential are much better considered by analysis of such accurate data. Method: Statistical model (SM) calculations of the (alpha,x) reaction cross sections have been carried out using model parameters which were previously obtained by analyzing independent data, particularly gamma-ray strength functions, and taking into account their uncertainties and questions of extrapolation for nuclei without similar data. Results: Consistent description of the recent alpha-induced reaction data is provided by the above-mentioned optical potential with no empirical rescaling factors of either its own parameters or the gamma and/or nucleon widths. Effects of still uncertain SM parameters on calculated alpha-induced reaction cross sections and conclusions on the alpha-OMP can be now discussed due to unprecedented precision of the new data. Conclusions: The alpha-particle optical potential has been confirmed at incident energies below the Coulomb barrier using statistical-model parameters validated through a former analysis of independent data.
Comments:
14 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1904.05140 [pdf]
PRC(2019)·7 citations
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

Squeezed back-to-back correlations of bosons with nonzero widths in relativistic heavy-ion collisions

Towards an ab initio covariant density functional for nuclear structure

Role of consistent parameter sets in an assessment of the alpha-particle optical potential below the Coulomb barrier

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