Nuclear Theory·nucl-th

Wednesday·February 26, 2020

6 papers—3 primary·3 cross-listed

01
Constraints on the symmetry energy and its associated parameters from nuclei to neutron stars
Yingxun Zhang · Min Liu · Cheng-Jun Xia · Zhuxia Li · Subrata Kumar Biswal
The symmetry energy obtained with the effective Skyrme energy density functional is related to the values of isoscalar effective mass and isovector effective mass, which is also indirectly related to the incompressibility of symmetric nuclear matter. In this work, we analyze the values of symmetry energy and its related nuclear matter parameters in five-dimensional parameter space by describing the heavy ion collision data, such as isospin diffusion data at 35 MeV/u and 50 MeV/u, neutron skin of $^{208}$ Pb, and tidal deformability and maximum mass of neutron star. We obtain the parameter sets which can describe the isospin diffusion, neutron skin, tidal deformability and maximum mass of neutron star, and give the incompressibility $K_{0}$ =250.23 $\pm$ 20.16 MeV, symmetry energy coefficient $S_{0}$ =31.35 $\pm$ 2.08 MeV, the slope of symmetry energy $L$ =59.57 $\pm$ 10.06 MeV, isoscalar effective mass $m_{s}^{*} / m$ =0.75 $\pm$ 0.05 and quantity related to effective mass splitting $f_{I}$ =0.005 $\pm$ 0.170. At two times normal density, the symmetry energy we obtained is in 35-55 MeV. To reduce the large uncertainties of $f_{I}$ , more critical works in heavy ion collisions at different beam energies are needed.
nucl-thastro-ph.HEnucl-exPRC(2020)·85 citations
02
Scaled variables and the quark-hadron duality
A.S. Parvan🇷🇺
The thermodynamic quantities of the ideal gas of hadrons and the $(2 + 1)$ --flavor lattice QCD scaled by the effective degeneracy factors of the corresponding models are compared. We have found that in terms of the scaled variables the quark-hadron duality of the lattice QCD and the hadron resonance gas (HRG) model disappears. However, we have unexpectedly revealed that the scaled variables lead to the quark-hadron duality of the lattice QCD and the quantum ideal gas of kaons and antikaons, namely, the ideal gas of those hadrons that contain all the three quarks $u, d, s$ and their antiquarks. Satisfactory agreement between the scaled results of the kaon ideal gas and the lattice QCD data is achieved at large values of the volume in the entire temperature range. In the ideal gas of kaons there is no any phase transition. Nevertheless, in our calculations the scaled thermodynamic quantities of the ideal gas and the lattice QCD follow the same qualitative behavior and are consistent with each other especially at high temperatures in the perturbative region.
nucl-thhep-phEPJA(2020)·1 citation
03
Study of diffusion coefficients of identified particles at energies available at BNL Relativistic Heavy Ion Collider
Vivek Kumar Singh🇮🇳 · D. K. Mishra🇮🇳 · Zubayer Ahammed🇮🇳
Using event-by-event fluctuations, we study the diffusion parameters of net-charge, net-pion, net-kaon, and net-proton in the heavy-ion jet interaction generator (HIJING), and ultra-relativistic quantum molecular dynamics (UrQMD) models at different collision energies \sqsn available at BNL Relativistic Heavy Ion Collider (RHIC). The diffusion parameter ( $σ$ ) of net-charge and identified particles are estimated in rapidity space at various \sqsn. It is observed that, the $σ$ values are independent of collision energies but emphasises the particle-species dependence of diffusion coefficient in the QGP medium. The present work on particle-species dependence of diffusion coefficient provides a baseline for comparison with the experimental data.
nucl-thhep-phEPJA(2020)·1 citation
04
Projective Cooling for the transverse Ising model
Erik Gustafson🇺🇸
We demonstrate the feasibility of ground state preparation for the transverse Ising model using projective cooling, and show that the algorithm can effectively construct the ground state in the disordered (paramagnetic) phase. On the other hand, significant temperature effects are encountered in the ordered (ferromagnetic) phase requiring larger lattices to accurately simulate.
↳ hep-latcond-mat.stat-mechnucl-thquant-phPRD(2020)·17 citations
05
Quark-diquark string tension, excited baryonic resonances and thermal fluctuations
E. Megias🇪🇸 · E. Ruiz Arriola🇪🇸 · L.L. Salcedo🇪🇸
We study the baryonic fluctuations from second to eighth order involving electric charge, baryon number and strangeness below the quark-gluon plasma crossover and numerically known from lattice QCD calculations. By considering a particular realization of the Hadron Resonance Gas model, we provide evidence on the dominant role of quark-diquark degrees of freedom to describe excited baryonic resonances. After proving by means of suitable Polyakov loop correlators that the quark-diquark and the quark-antiquark forces coincide, $V_{q ˉ q} (r) = V_{q ˉ D} (r) + const$ , we find that the corresponding susceptibilities can be saturated with excited baryonic states in a quark-diquark model picture.
↳ hep-phhep-latnucl-thPhys.Scripta(2020)·2 citations
06
Pentaquark states from bound state approach with chiral partner structure
Ben-Teng Zhang🇨🇳 · Jun-Shuai Wang🇨🇳 · Yong-Liang Ma🇨🇳
The observation of the two states $P_{c} (4380)$ and $P_{c} (4445)$ [Phys.Rev.Lett. 115 (2015) 072001] solids the existence of the pentaquark state in Nature. In this work, we study the spectrum of the pentaquark states including one or two heavy quarks based on the bound state approach by binding the heavy-light mesons to the nucleon as a soliton in an effective Lagrangian approach. By regarding the $H$ doublet and $G$ doublet as chiral partners to each other and coupling them to light mesons with a minimal derivative, the chiral partner structure of the pentaquark states is calculated. We find that the bound state approach prefers to arrange $P_{c}^{+} (4440)$ and $P_{c} (4457)$ into a heavy quark doublet $(\frac{1}{2}^{-}, \frac{3}{2}^{-})$ so both decay to $J / ψ p$ through the $S$ -wave. The predicted spectrum shown in this work serves as a guide for the experimental hunting of more pentaquark states.
↳ hep-phnucl-th5 citations

Affiliations

first authorsco-authorsvia INSPIRE

Constraints on the symmetry energy and its associated parameters from nuclei to neutron stars

Scaled variables and the quark-hadron duality

Study of diffusion coefficients of identified particles at energies available at BNL Relativistic Heavy Ion Collider

Projective Cooling for the transverse Ising model

Quark-diquark string tension, excited baryonic resonances and thermal fluctuations

Pentaquark states from bound state approach with chiral partner structure

Affiliations