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Nuclear Theory·nucl-th

Tuesday·June 27, 2023

17 papers—6 primary·11 cross-listed

All17Primary6Cross-lists11
  1. 01

    Linear Boltzmann transport for jet propagation in the quark-gluon plasma: Inelastic processes and jet modification

    Tan Luo🇨🇳 · Yayun He🇨🇳 · Shanshan Cao🇨🇳 · Xin-Nian Wang🇨🇳

    A Linear Boltzmann Transport (LBT) Monte Carlo model has been developed to describe jet propagation and interaction with the quark-gluon plasma (QGP) in relativistic heavy-ion collisions. A complete set of elastic scattering processes and medium-induced gluon emissions based on the higher-twist formalism are incorporated for both jet shower and medium recoil partons. It has been employed to describe experimental data on large transverse momentum hadron and jet spectra, correlation and jet substructures in high-energy heavy-ion collisions. We document in detail the structure of the model and validation of the Monte Carlo implementations of the physics processes in LBT, in particular, the inelastic process of medium-induced gluon radiation. We carry out a comprehensive examination of the jet-medium interaction as implemented in LBT through energy loss and momentum broadening of a single hard parton, the energy and transverse momentum transfer from leading partons to medium-induced gluons and jet-induced medium excitation, and medium modification of reconstructed jets in a static and uniform medium. With realistic and event-by-event hydrodynamic medium in heavy-ion collisions, we compute and compare to experimental data on the jet cone-size dependence of the single inclusive jet suppression at both Relativistic Heavy-Ion Collider (RHIC) and the Large Hadron Collider (LHC), the dijet asymmetry at LHC and -jet correlation at RHIC. Effects of medium-induced gluon emissions and jet-induced medium excitation on jet observables are systematically examined. Rescatterings of the radiated gluons and recoil partons with the QGP are found essential to account for the enhancement of soft particle yield toward the edge of the jet cone.

    nucl-thhep-phPRC(2024)·49 citations
  2. 02

    Impact of Multiple Phase Transitions in Dense QCD on Compact Stars

    Armen Sedrakian🇩🇪

    This review covers several recent developments in the physics of dense QCD with an emphasis on the impact of multiple phase transitions on astrophysical manifestations of compact stars. It is conjectured that pair-correlated quark matter in -equilibrium is within the same universality class as spin-imbalanced cold atoms and the isospin asymmetrical nucleonic matter. This then implies the emergence of phases with broken space symmetries and tri-critical (Lifshitz) points. We construct an equation of state (EoS) that extends the two-phase EoS of dense quark matter within the constant speed of sound parameterization by adding a conformal fluid with a speed of sound at densities , where is the saturation density. With this input, we construct static, spherically symmetrical compact hybrid stars in the mass--radius diagram, recover such features as the twins and triplets, and show that the transition to conformal fluid leads to the spiraling-in of the tracks in this diagram. Stars on the spirals are classically unstable with respect to the radial oscillations but can be stabilized if the conversion timescale between quark and nucleonic phases at their interface is larger than the oscillation period. Finally, we review the impact of a transition from high-temperature gapped to low-temperature gapless two-flavor phase on the thermal evolution of hybrid stars.

    nucl-thastro-ph.HEhep-phParticles(2023)·8 citations
  3. 03

    Baryonic models of ultra-low-mass compact stars for the central compact object in HESS J1731-347

    Jia Jie Li (SWU, Chongqing)🇨🇳 · Armen Sedrakian (FIAS, Frankfurt and Wroclaw U.)🇩🇪

    The recent attempt on mass and radius inference of the central compact object within the supernova remnant HESS J1731-347 suggests for this object an unusually low mass of and a small radius of \,km. We explore the ways such a result can be accommodated within models of dense matter with heavy baryonic degrees of freedom which are constrained by the multi-messenger observations. We find that to do so using only purely nucleonic models, one needs to assume a rather small value of the slope of symmetry energy . Once heavy baryons are included higher values of the slope become acceptable at the cost of a slightly reduced maximum mass of static configuration. These two scenarios are distinguished by the particle composition and will undergo different cooling scenarios. In addition, we show that the universalities of the -Love- relations for static configurations can be extended to very low masses without loss in their accuracy.

    nucl-thhep-phPLB(2023)·27 citations
  4. 04

    Universal relations for compact stars with heavy baryons

    Jia Jie Li (SWU, Chongqing)🇨🇳 · Armen Sedrakian (FIAS Frankfurt and Wroclaw U.)🇩🇪 · Fridolin Weber (San Diego State U. and CASS, San Diego)🇺🇸

    A set of hadronic equations of state derived from covariant density functional theory and constrained by terrestrial experiments, and astrophysical observations, in particular by the NICER experiment inferences is used to explore the universal relations among the global properties of compact stars containing heavy baryons at high densities. We confirm the validity of universal -Love- relations connecting the moment of inertia , the tidal deformability (), and the spin-induced quadrupole moment () for isolated non-rotating stars. We further confirm the validity of the -- relations connecting the moment of inertia, compactness , and quadrupole moment for uniformly and slowly rotating stars, and extend the validity of these relations to maximally rotating sequences. We then investigate the relations between integral parameters of maximally rotating and static compact stars. The universalities are shown to persist for equations of state and compositions containing hyperons and degrees of freedom. When heavy baryons are included, however, the radial profiles of integrands in expressions of global properties exhibit ``bumps", which are not present in the case of nucleonic stars in which case the profiles are smooth. We determine the coefficients entering the universal relations in the case of hyperonic and -resonance containing stars.

    nucl-thastro-ph.HEastro-ph.SRPRC(2023)·26 citations
  5. 05

    Shear viscosity expression for a graphene system in relaxation time approximation

    Cho Win Aung · Thandar Zaw Win · Gaurav Khandal · Sabyasachi Ghosh

    We have gone through the detailed microscopic calculation of the shear viscosity of a 2-dimensional graphene system in the relaxation time approximation-based kinetic theory framework. After getting its final expressions, we compared it with the shear viscosity expressions of other possible 2-dimensional as well as 3-dimensional nonrelativistic and ultra-relativistic fluid systems. The aim of the comparison is to reveal how their different one-body dispersion relations affect their many-body fluid properties like shear viscosity and the viscosity to entropy density ratio. It is also aimed to reveal the 3-dimension to the 2-dimension transformation of their mathematical structures. We have numerically explored the differences in their order of magnitude and dependence on thermodynamical parameters-temperature and chemical potential. Marking two thermodynamical domains-Dirac fluid and Fermi liquid-for a 2-dimensional graphene system, we have noticed that shear viscosity, entropy density as well as their ratios decrease toward saturated values when one goes from Fermi liquid to Dirac fluid domain. When one shifts from mili-electron volt scales of temperature and chemical potential in condensed matter physics location to their mega-electron volt scales in high energy physics location, then the same results may be expected for hot quark matter case, where the transition from the neutron star to early universe domains may be considered as Fermi liquid to Dirac fluid transition.

    nucl-thcond-mat.stat-mechPRB(2023)·12 citations
  6. 06

    The Entanglement of Elastic and Inelastic Scattering

    Gerald A. Miller🇺🇸

    The entanglement properties of systems in which elastic and inelastic reactions occur in projectile-target interactions is studied. A new measure of entanglement, the scattering entropy, based on the unitarity of the matrix (probability conservation), is suggested. Using simple models for both low- and high-energy interactions, the amount of entanglement is found to track with the strength of the inelastic interaction. The familiar example of the classical ``black disk", total absorption, model is found to correspond to maximum entanglement. An analysis of high-energy scattering data shows that entanglement is near maximum for lab energies greater than about 1 GeV, showing that the total absorption model is a reasonable starting point for understanding the data.

    nucl-thhep-phnucl-exquant-phPRC(2023)·21 citations

Affiliations

first authorsco-authorsvia INSPIRE