Nuclear Theory·nucl-th

Thursday·November 9, 2023

8 papers—3 primary·5 cross-listed

01
Dynamics of causal hydrodynamic fluctuations in an expanding system
Shin-ei Fujii🇯🇵 · Tetsufumi Hirano🇯🇵
We develop a framework of causal hydrodynamic fluctuations in one-dimensional expanding system performing linearisation of the hydrodynamic equations around the boost invariant solution. Through the description of space-time evolution of thermodynamic variables and flow velocity, we find a novel phenomenon that the structure of thermodynamic variables is almost frozen. We also show that two-particle correlation functions of final hadrons after freezeout are closely related with the mass of hadrons and properties of the medium such as viscosity, relaxation time and equation of state.
nucl-thhep-phnucl-exEPJ Web Conf.(2024)·1 citation
02
Fully-heavy baryons $QQQ$ in vacuum and hot QCD medium
Jiaxing Zhao🇫🇷 · Shuzhe Shi🇨🇳
We study the properties of fully-heavy baryons in the vacuum and the hot QCD medium, which is created in relativistic heavy-ion collisions. Masses and wave functions of $Ω_{ccc}$ , $Ω_{cc b}$ , $Ω_{bb c}$ , and $Ω_{bbb}$ up to the second radial excited states are obtained by solving the three-body Schrödinger equation with Hyperspherical Harmonics method. With parameters completely fixed by fitting quarkonium boundstates in vacuum, we predicted the masses for $1 S$ , $2 S$ , and $3 S$ states of fully-heavy baryons. We also computed the temperature dependence of baryon masses and the thermal widths in a hot QCD medium. These properties are important to precise study of fully-heavy baryon production in heavy ion collisions.
nucl-thhep-phPRC(2024)·13 citations
03
Quick Guides for Use of the CompOSE Data Base
Veronica Dexheimer · Marco Mancini · Micaela Oertel · Constanca Providencia · Laura Tolos · Stefan Typel
We present a combination of two quick guides aimed at summarizing relevant information about the CompOSE nuclear equation of state repository. The first is aimed at nuclear physicists and describes how to provide standard equation of state tables. The second quick guide is meant for users and describes the basic procedures to obtain customized tables with equation of state data. Several examples are included to help providers and users to understand and benefit from the CompOSE database.
nucl-thastro-ph.HEastro-ph.SRnucl-exParticles(2022)·18 citations
04
Quark confinement in an equiparticle quark model: application to stellar matter
Isabella Marzola🇧🇷 · Sérgio B. Duarte🇧🇷 · César H. Lenzi🇧🇷 · Odilon Lourenço🇧🇷
We perform an improvement in a thermodynamical consistent model with density dependent quark masses ( $m_{u, d, s}^{'}$ ) by introducing effects of quark confinement/deconfinement phase transition, at high density regime and zero temperature, by means of the traced Polyakov loop ( $Φ$ ). We use realistic values for the current quark masses, provided by the Particle Data Group, and replace the constants of the interacting part of $m_{u, d, s}^{'}$ by functions of $Φ$ , leading to a first order phase transition structure, for symmetric and stellar quark matter, with $Φ$ being the order parameter. We show that the improved model points out the direction of the chiral symmetry restoration due to the emergence of a deconfined phase. In another application, we construct quark stars mass-radius profiles, obtained from this new model, and show to be possible to satisfy recent astrophysical observational data coming from the LIGO and Virgo Collaboration, and the NICER mission concerning the millisecond pulsars PSR J0030+0451, and PSR J0740+6620.
↳ astro-ph.HEhep-phnucl-thPRD(2023)·4 citations
05
Viscosity of non equilibrium hot $&$ dense QCD drop formed at LHC
J. R. Alvarado García🇲🇽 · I. Bautista🇲🇽 · A. Fernández Téllez🇲🇽 · P. Fierro🇲🇽
We compute the bulk, $ζ$ , and shear, $η$ , viscosity over entropy density, $s$ , for the QCD matter formed in small collision systems at LHC. We consider a scenario of the String Percolation Model by proposing a global form of the color reduction factor that describes both the thermodynamic limit and its maximum deviation due to small-bounded effects. Our method involves estimations at vanishing baryon-chemical potential, assuming local equilibrium for string clusters in the initial state. To compute $η / s$ , we employed a kinetic approach that accounts QCD states as an ideal gas of partons, while $ζ / s$ is computed by using two different approaches: a simple kinetic formula and the causal dissipative relativistic fluid dynamics formulation. Our results align with Lattice QCD computations and Bayesian methods and are consistent with holographic conjecture bounds. Furthermore, our findings support the notion of a strongly interacting medium, similar to that observed in nuclear collisions, albeit with a phase transition occurring outside the thermodynamic limit.
↳ hep-phnucl-thPRD(2023)·3 citations
06
Restoring symmetries in quantum computing using Classical Shadows
Edgar Andres Ruiz Guzman🇫🇷 · Denis Lacroix🇫🇷
We introduce a method to enforce some symmetries starting from a trial wave-function prepared on quantum computers that might not respect these symmetries. The technique eliminates the necessity for performing the projection on the quantum computer itself. Instead, this task is conducted as a post-processing step on the system's "Classical Shadow". Illustrations of the approach are given for the parity, particle number, and spin projectors that are of particular interest in interacting many-body systems. We compare the method with another classical post-processing technique based on direct measurements of the quantum register. We show that the present scheme can be competitive to predict observables on symmetry-restored states once optimization through derandomization is employed. The technique is illustrated through its application to compute the projected energy for the pairing model Hamiltonian.
↳ quant-phcond-mat.str-elnucl-thEPJA(2024)·18 citations
07
Analysis of $D D^{*}$ and $D ˉ^{(*)} Ξ_{cc}^{(*)}$ molecule by one boson exchange model based on Heavy quark symmetry
Tatsuya Asanuma🇯🇵 · Yasuhiro Yamaguchi🇯🇵 · Masayasu Harada🇯🇵
Numerous exotic hadrons with heavy quarks have been reported in the experiments. In such states, symmetries of heavy quarks are considered to play a significant role. In particular, the superflavor symmetry, or also called the heavy quark anti-diquark symmetry is one of the interesting symmetries, which links a quark $Q$ to an anti-diquark $Q ˉ Q ˉ$ having the same color representation as $Q$ . In this paper, we study a $D ˉ Ξ_{cc}$ molecular state as a superflavor partner of the doubly charm tetraquark $T_{cc}$ reported by LHCb recently. $T_{cc}$ locating slightly below the $D D^{*}$ threshold is a candidate of the hadronic molecule. Thus by replacing the singly charm meson $D^{(*)}$ with the doubly charm baryon $Ξ_{cc}^{(*)}$ , superflavor symmetry predicts the existence of the $D ˉ^{(*)} Ξ_{cc}^{(*)}$ bound state. We employ the one boson exchange model respecting with the heavy quark spin symmetry where the parameter is obtained to reproduce the $T_{cc}$ binding energy. We apply this model with superflavor symmetry to the $D ˉ^{(*)} Ξ_{cc}^{(*)}$ molecule and predict a bound state with $I (J^{P}) = 0 (\frac{1}{2}^{-})$ . If the pentaquark state corresponding to $D ˉ^{(*)} Ξ_{cc}^{(*)}$ molecular state is observed in future experiments as predicted in this work, it is more likely that $T_{cc}$ is a $D D^{*}$ molecular state.
↳ hep-phnucl-thPRD(2024)·19 citations
08
What can we learn about the unstable equation-of-state branch from neutron-star mergers?
Maximiliano Ujevic🇧🇷 · Rahul Somasundaram🇺🇸 · Tim Dietrich🇩🇪 · Jerome Margueron🇫🇷 · Ingo Tews🇺🇸
The Equation of State (EOS) of dense strongly-interacting matter can be probed by astrophysical observations of neutron stars (NS), such as X-ray detections of pulsars or the measurement of the tidal deformability of NSs during the inspiral stage of NS mergers. These observations constrain the EOS at most up to the density of the maximum-mass configuration, $n_{TOV}$ , which is the highest density that can be explored by stable NSs for a given EOS. However, under the right circumstances, binary neutron star (BNS) mergers can create a postmerger remnant that explores densities above $n_{TOV}$ . In this work, we explore whether the EOS above $n_{TOV}$ can be measured from gravitational-wave or electromagnetic observations of the postmerger remnant. We perform a total of twenty-five numerical-relativity simulations of BNS mergers for a range of EOSs and find no case in which different descriptions of the matter above $n_{TOV}$ have a detectable impact on postmerger observables. Hence, we conclude that the EOS above $n_{TOV}$ can likely not be probed through BNS merger observations for the current and next generation of detectors.
↳ astro-ph.HEgr-qcnucl-thApJL(2024)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE