Nuclear Theory·nucl-th

Wednesday·July 27, 2022

16 papers—8 primary·8 cross-listed

01
[Submitted on 25 Jul 2022]
Multi-Stage Heavy Quark Transport in Ultra-relativistic Heavy-ion Collisions
Wenkai Fan🇺🇸
The quark gluon plasma (QGP) is one of the most interesting forms of matter providing us with insight on quantum chromodynamics (QCD) and the early universe. It is believed that the heavy-ion collision experiments at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) have created the QGP medium by colliding two heavy nuclei at nearly the speed of light. Since the collision happens really fast, we can not observe the QGP directly. Instead, we look at the hundreds or even thousands of final hadrons coming out of the collision. In particular, jet and heavy flavor observables are excellent probes of the transport properties of such a medium. On the theoretical side, computational models are essential to make the connections between the final observables and the plasma. Previously studies have employed a comprehensive multistage modeling approach of both the probes and the medium. In this dissertation, heavy quarks are investigated as probes pf the QGP. First, the framework that describes the evolution of both soft and hard particles during the collision is discussed, which includes initial condition, hydrodynamical expansion, parton transport, hadronization, and hadronic rescattering. It has recently been organized into the Jet Energy-loss Tomography with a Statistically and Computationally Advanced Program Envelope (JETSCAPE) framework, which allows people to study heavy-ion collision in a more systematic manner. To study the energy loss of hard partons inside the QGP medium, the linear Boltzmann transport model (LBT) and in medium DGLAP evolution (implemented in the MATTER model) are combined and have achieved a simultaneous description of both charged hadron, D meson, and inclusive jet observables. To further extract the transport coefficients, a Bayesian analysis is conducted which constrains the parameters in the transport models.
Comments:
PhD thesis
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2207.12452 [pdf]
2 citations
02
[Submitted on 25 Jul 2022]
Unveiling the dynamics of nucleosynthesis in relativistic heavy-ion collisions
Kai-Jia Sun🇺🇸 · Rui Wang🇨🇳 · Che Ming Ko🇺🇸 · Yu-Gang Ma🇨🇳 · Chun Shen🇺🇸
Like nucleosynthesis during the early universe, light nuclei are also produced in relativistic heavy-ion collisions. Although the deuteron ( $d$ ) yields in these collisions can be well described by the statistical hadronization model (SHM), which assumes that particle yields are fixed at a common chemical freezeout near the phase boundary between the quark-gluon plasma and the hadron gas, the recently measured triton ( $^{3} H$ ) yields in Au+Au collisions at $s_{N N} = 7.7 - 200$ GeV are overestimated systematically by this model. Here, we develop a comprehensive kinetic approach to study the effects of hadronic re-scatterings, such as $π N N \leftrightarrow π d$ and $π N N N \leftrightarrow π^{3} H (^{3} He)$ , on $d$ , $^{3} H$ , and $^{3} He$ production in these collisions. We find that these reactions have little effects on the deuteron yield but reduce the $^{3} H$ and $^{3} He$ yields by about a factor of 1.8 from their initial values given by the SHM. This finding helps resolve the overestimation of triton production in the SHM and provides the evidence for hadronic re-scattering effects on nucleosynthesis in relativistic heavy-ion collisions.
Comments:
6 pages, 4 figures. arXiv admin note: text overlap with arXiv:2106.12742
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2207.12532 [pdf]
Nature Commun.(2024)·66 citations
03
[Submitted on 25 Jul 2022]
QCD Equilibrium and Dynamical Properties from Holographic Black Holes
Joaquin Grefa🇺🇸 · Mauricio Hippert🇺🇸 · Jorge Noronha🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸 · Israel Portillo🇺🇸 · Claudia Ratti🇺🇸 · Romulo Rougemont🇧🇷
By using gravity/gauge correspondence, we employ an Einstein-Maxwell-Dilaton model to compute the equilibrium and out-of-equilibrium properties of a hot and baryon rich strongly coupled quark-gluon plasma. The family of 5-dimensional holographic black holes, which are constrained to mimic the lattice QCD equation of state at zero density, is used to investigate the temperature and baryon chemical potential dependence of the equation of state. We also obtained the baryon charge conductivity, and the bulk and shear viscosities with a particular focus on the behavior of these observables on top of the critical end point and the line of first order phase transition predicted by the model.
Comments:
Proceedings for the 37th Winter Workshop on Nuclear Dynamics
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2207.12564 [pdf]
Rev.Mex.Fis.Suppl.(2022)·6 citations
04
[Submitted on 26 Jul 2022]
QCD Equation of State and Phase Diagram from Holographic Black Holes
Joaquin Grefa🇺🇸 · Jorge Noronha🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸 · Israel Portillo🇺🇸 · Claudia Ratti🇺🇸 · Romulo Rougemont🇧🇷
By using the AdS/CFT correspondence, we construct an Einstein-Maxwell-Dilaton model to map the thermodynamics of strongly interacting matter. The holographic model, constrained to reproduce the lattice QCD equation of state at zero baryon chemical potential, predicts a critical end point and a first order phase transition line. We also obtain the equation of state of the model for a large region of the phase diagram. We characterize the crossover transition region by two lines, one associated to the inflection of the second order baryon susceptibility, and another one associated to the minimum of the square of the speed of sound along trajectories of constant entropy per baryon number. We observe that both lines merge at the critical point.
Comments:
6 pages, 3 figures, contribution to the proceedings of The International conference on Critical Point and Onset of Deconfinement - CPOD2021
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2207.12591 [pdf]
PoS(2022)·1 citation
05
[Submitted on 26 Jul 2022]
Effects of the tensor force on low-energy heavy-ion fusion reactions: A mini review
Xiang-Xiang Sun · Lu Guo
In recent several years, the tensor force, one of the most important components of the nucleon-nucleon force, has been implemented in time-dependent density functional theories and it has been found to influence many aspects of low-energy heavy-ion reactions, such as dissipation dynamics, sub-barrier fusions, low-lying vibration states of colliding partners. Especially, the effects of tensor force on fusion reactions have been investigated from the internuclear potential to fusion cross sections systematically. In this work we present a mini review on the recent progresses on this topic. Considering the recent progress of low-energy reaction theories, we will also mention more possible effects of the tensor force on reaction dynamics.
Comments:
30 pages, 4 figures, Accepted Manuscript in Commun. Theor. Phys
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2207.12918 [pdf]
Commun.Theor.Phys.(2022)·11 citations
06
[Submitted on 26 Jul 2022]
Microscopic study of the compound nucleus formation in cold-fusion reactions
Xiang-Xiang Sun · Lu Guo
The understanding of the fusion probability is of particular importance to reveal the mechanism of producing superheavy elements. We present a microscopic study of the compound nucleus formation by combining time-dependent density functional theory, coupled-channels approach, and dynamical diffusion models. The fusion probability and compound nucleus formation cross sections for cold-fusion reactions $^{48}$ Ca+ $^{208}$ Pb, $^{50}$ Ti+ $^{208}$ Pb, and $^{54}$ Cr+ $^{208}$ Pb are investigated and it is found that the deduced capture barriers, capture cross sections for these reactions are consistent with experimental data. Above the capture barrier, our calculations reproduce the measured fusion probability reasonably well. Our studies demonstrate that the restrictions from the microscopic dynamic theory improve the predictive power of the coupled-channels and diffusion calculations.
Comments:
9 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2207.12924 [pdf]
PRC(2022)·18 citations
07
[Submitted on 26 Jul 2022]
Reaching percolation and conformal limits in neutron stars
Michał Marczenko🇵🇱 · Larry McLerran🇺🇸 · Krzysztof Redlich🇵🇱 · Chihiro Sasaki🇵🇱
Generating an ensemble of equations of state that fulfill multimessenger constraints, we statistically determine the properties of dense matter found inside neutron stars (NSs). We calculate the speed of sound and trace anomaly and demonstrate that they are driven towards their conformal values at the center of maximally massive NSs. The local peak of the speed of sound is shown to be located at values of the energy and particle densities which are consistent with deconfinement and percolation conditions in QCD matter. We also analyze fluctuations of the net-baryon number density in the context of possible remnants of critical behavior. We find that the global maxima of the variance of these fluctuations emerge at densities beyond those found in the interiors of NSs.
Comments:
version accepted for publication in Physical Review C
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2207.13059 [pdf]
PRC(2023)·112 citations
08
[Submitted on 26 Jul 2022]
Mirror Neutron Stars: How QCD can be used to study dark matter through gravitational waves
Maurício Hippert🇺🇸 · Jack Setford🇺🇸 · Hung Tan🇺🇸 · David Curtin🇺🇸 · Jacquelyn Noronha-Hostler🇨🇦 · Nicolás Yunes🇺🇸
Given the lack of empirical evidence of weakly interacting dark matter, it is reasonable to look to other candidates such as a confining dark sector with a similar number of particles as the standard model. Twin Higgs mirror matter is one such model that is a twin of the standard model with particles masses 3--6 times heavier than the standard model that solves the hierarchy problem. This generically predicts mirror neutron stars, degenerate objects made entirely of mirror nuclear matter. We find their structure using a realistic equation of state from crust (nuclei) to core (relativistic mean-field model) and scale the particle masses using lattice QCD results. We find that mirror neutron stars have unique signatures that are detectable via gravitational waves and binary pulsars, that provides an intriguing possibility for probing dark matter.
Comments:
prepared for the proceedings of Quark Matter 2022. 6 pages, 1 figure
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2207.13063 [pdf]
Acta Phys.Polon.Supp.(2023)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE