Nuclear Theory·nucl-th

Wednesday·July 7, 2021

9 papers—3 primary·6 cross-listed

01
Elliptic Flow of Particles under the Influence of Electromagnetic Field Evolution in Relativistic Heavy Ion Collision
Tewodros Gezhagn🇪🇹 · A. K. Chaubey🇪🇹
The bending of flow of identified particles from the relativistic heavy-ion collision is investigated using the iEBE-VISHNU framework. The Maxwell's equations are applied to compute the incremental drift velocity and the change in the elliptic flow of particles from the four sources of the electric force, which are of coulomb (EC), Lorentz (EL), Faraday (EF) and Plasma-based. We find out that the field evolution arouses flow at lower transverse momentum and suppresses it at higher. Heavier particles get higher initial push, and particles and their anti-particles get crudely the same elliptic flow changes. Moreover, elliptic flow is found to show different percentage increase for different collision energies. To conclude, the present study shows that besides the inclusion of electromagnetic fields, the increase in collision energy affects the elliptic flow of particles in a non-uniform fashion throughout the evolution. Further study by softening many of the crude assumptions we made and keeping the functionality of parameters is needed to establish a better understanding of the electromagnetic field evolution and its effects on the created system.
nucl-thSch J Phys Math Stat, 2021 Feb8(2): 35-44·0 citations
02
Properties of Skyrme force as a residual interaction in beyond mean-field theories
Mitsuru Tohyama
In an effort to find an effective interaction which can consistently be used for both the mean-field part and the residual part in beyond mean-field theories, properties of the Skyrme interactions as a residual interaction are investigated. The time-dependent density-matrix theory (TDDM) is used as a beyond mean-field theory and the ground states of $^{16}$ O and $^{40}$ Ca are calculated using the five standard parametrizations of the Skyrme interaction which differs in density and momentum dependence. It is found that the Skyrme interaction which has strong density dependence and weak momentum dependence induces substantial ground-state correlations comparable to the results of other theoretical calculations.
nucl-thPTEP(2021)·2 citations
03
Enormous nuclear surface diffuseness in the exotic Ne and Mg isotopes
V. Choudhary · W. Horiuchi · M. Kimura · R. Chatterjee
The density profile of exotic nuclei can be a rich source of information on the nuclear surface. In particular, the nuclear surface diffuseness parameter is correlated with the occupation probability of nucleons indistinct nuclear orbits, especially those with low angular momenta. The aim of this paper is to investigate the relationship between the nuclear surface diffuseness and spectroscopic information of neutron rich Ne and Mg isotopes both at the cusp and inside the island of inversion. We use the microscopic antisymmetrized molecular dynamics model to calculate these densities and other spectroscopic information. A two-parameter Fermi density distribution is then used to define the diffuseness parameter. To relate them with observables, the nucleon-nucleus elastic scattering differential cross section is calculated with the demand that they reproduce the first peak position and its magnitude. A marked increase in the occupation of neutrons in the pf-orbit is noted in Ne and Mg isotopes from N=19 onwards. We observed that the nuclear diffuseness is strongly correlated with the nuclear deformation, in the island of inversion, and gradually increases with the occupation of neutrons in the 1p3/2 orbit. This result is also confirmed by a single-particle estimate of the valence neutron density distribution. An exception is noted for 35-37Mg, where the filling up of the holes in the sd-shell partially compensates the increase in diffuseness due to filling up of the 1p3/2 orbit. Information on nuclear density profile of neutron rich medium mass nuclei can be reliably extracted by studying the first diffraction peak of the nucleon-nucleus elastic scattering differential cross section. The enormous surface diffuseness of Ne and Mg isotopes, in the island of inversion, could be attributed to the increasing neutron occupation of the 1p3/2 orbit.
nucl-thPRC(2021)·22 citations
04
Electro-magnetic field fluctuation and its correlation with the participant plane in Au+Au and isobaric collisions at $s_{N N} = 200$ GeV
Sk Noor Alam🇮🇳 · Victor Roy🇮🇳 · Shakeel Ahmad🇮🇳 · Subhasis Chattopadhyay🇮🇳
Intense transient electric ({\bf E}) and magnetic ({\bf B}) fields are produced in the high energy heavy-ion collisions. The electromagnetic fields produced in such high-energy heavy-ion collisions are proposed to give rise to a multitude of exciting phenomenon including the Chiral Magnetic Effect. We use a Monte Carlo (MC) Glauber model to calculate the electric and magnetic fields, more specifically their scalar product $E \cdot B$ , as a function of space-time on an event-by-event basis for the Au+Au collisions at $s_{N N} = 200$ GeV for different centrality classes. We also calculate the same for the isobars Ruthenium and Zirconium at $s_{N N} = 200$ GeV. In the QED sector $E \cdot B$ acts as a source of Chiral Separation Effect, Chiral Magnetic Wave, etc., which are associated phenomena to the Chiral Magnetic Effect. We also study the relationships between the electromagnetic symmetry plane angle defined by $E \cdot B$ ( $ψ_{E . B}$ ) and the participant plane angle $ψ_{P}$ defined from the participating nucleons for the second-fifth order harmonics.
↳ hep-phnucl-thPRD(2021)·12 citations
05
Scattering and gluon emission in a color field: a light-front Hamiltonian approach
Meijian Li🇫🇮 · Tuomas Lappi🇫🇮 · Xingbo Zhao🇨🇳
We develop a numerical method to nonperturbatively study scattering and gluon emission of a quark from a colored target using a light-front Hamiltonian approach. The target is described as a classical color field, as in the Color Glass Condensate effective theory. The Fock space of the scattering system is restricted to the $∣ q ⟩ + ∣ q g ⟩$ sectors, but the time evolution of this truncated system is solved exactly. This method allows us to study the interplay between coherence and multiple scattering in gluon emission. It could be applied both to studying subeikonal effects in high energy scattering and to understanding jet quenching in a hot plasma.
↳ hep-phnucl-thPRD(2021)·32 citations
06
Hyperonic neutron stars: reconciliation between nuclear properties and NICER and LIGO/VIRGO results
Luiz L. Lopes🇧🇷
Using a extended version of the Quantum Hadrodynamics (QHD), I propose a new microscopic equation of state (EoS) able to correctly reproduce the main properties of symmetric nuclear matter at the saturation density, as well produce massive neutron stars and satisfactory results for the radius and the tidal parameter $Λ$ . I show that even when hyperons are present, this EoS is able to reproduce at least 2.00 solar masses neutron star. The constraints about the radius of a $2.00 M_{⊙}$ and the minimum mass that enable direct Urca effect are also checked.
↳ hep-phastro-ph.HEnucl-thCommun.Theor.Phys.(2022)·26 citations
07
Baryon transport and the QCD critical point
Lipei Du (Ohio State U.)🇺🇸 · Xin An (North Carolina U.)🇺🇸 · Ulrich Heinz (Ohio State U.)🇺🇸
Fireballs created in relativistic heavy-ion collisions at different beam energies have been argued to follow different trajectories in the QCD phase diagram in which the QCD critical point serves as a landmark. Using a (1+1)-dimensional model setting with transverse homogeneity, we study the complexities introduced by the fact that the evolution history of each fireball cannot be characterized by a single trajectory but rather covers an entire swath of the phase diagram, with the finally emitted hadron spectra integrating over contributions from many different trajectories. Studying the phase diagram trajectories of fluid cells at different space-time rapidities, we explore how baryon diffusion shuffles them around, and how they are affected by critical dynamics near the QCD critical point. We find a striking insensitivity of baryon diffusion to critical effects. Its origins are analyzed and possible implications discussed.
↳ hep-phnucl-exnucl-thPRC(2021)·43 citations
08
Non-Abelian Half-Quantum Vortices in $^{3} P_{2}$ Topological Superfluids
Yusuke Masaki · Takeshi Mizushima · Muneto Nitta
$^{3} P_{2}$ superfluids realized in neutron stars are the largest topological quantum matters in our Universe. We establish the existence and stability of non-Abelian half-quantum vortices (HQVs) in $^{3} P_{2}$ superfluids with strong magnetic fields. Using a self-consistent microscopic approach, we find that a singly quantized vortex is energetically destabilized into a pair of two non-Abelian HQVs owing to the strongly spin-orbit-coupled pairing. We find a topologically protected Majorana fermion on each HQV, thereby providing two-fold non-Abelian anyons characterized by both Majorana fermions and a non-Abelian first homotopy group.
↳ cond-mat.supr-conastro-ph.HEnucl-thPRB(2022)·19 citations
09
Wilson line correlators beyond the large- $N_{c}$
Johannes Hamre Isaksen🇳🇴 · Konrad Tywoniuk🇳🇴
We study hard $1 \to 2$ final-state parton splittings in the medium, and put special emphasis on calculating the Wilson line correlators that appear in these calculations. As partons go through the medium their color continuously rotates, an effect that is encapsulated in a Wilson line along their trajectory. When calculating observables, one typically has to calculate traces of two or more medium-averaged Wilson lines. These are usually dealt with in the literature by invoking the large- $N_{c}$ limit, but exact calculations have been lacking in many cases. In our work, we show how correlators of multiple Wilson lines appear, and develop a method to calculate them numerically to all orders in $N_{c}$ . Initially, we focus on the trace of four Wilson lines, which we develop a differential equation for. We will then generalize this calculation to a product of an arbitrary number of Wilson lines, and show how to do the exact calculation numerically, and even analytically in the large- $N_{c}$ limit. Color sub-leading corrections, that are suppressed with a factor $N_{c}^{- 2}$ relative to the leading scaling, are calculated explicitly for the four-point correlator and we discuss how to extend this method to the general case. These results are relevant for high- $p_{T}$ jet processes and initial stage physics at the LHC.
↳ hep-phhep-thnucl-thJHEP(2021)·28 citations

Affiliations

first authorsco-authorsvia INSPIRE