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
09
[Submitted on 25 Jul 2022] (cross-list from quant-ph)
Parallelization techniques for quantum simulation of fermionic systems
Jacob Bringewatt🇺🇸 · Zohreh Davoudi🇺🇸
Mapping fermionic operators to qubit operators is an essential step for simulating fermionic systems on a quantum computer. We investigate how the choice of such a mapping interacts with the underlying qubit connectivity of the quantum processor to enable (or impede) parallelization of the resulting Hamiltonian-simulation algorithm. It is shown that this problem can be mapped to a path coloring problem on a graph constructed from the particular choice of encoding fermions onto qubits and the fermionic interactions onto paths. The basic version of this problem is called the weak coloring problem. Taking into account the fine-grained details of the mapping yields what is called the strong coloring problem, which leads to improved parallelization performance. A variety of illustrative analytical and numerical examples are presented to demonstrate the amount of improvement for both weak and strong coloring-based parallelizations. Our results are particularly important for implementation on near-term quantum processors where minimizing circuit depth is necessary for algorithmic feasibility.
Comments:
27 pages, 12 figures; (v2) corrected a misplaced figure; (v3) updated for publication with minor changes
Subjects:
Quantum Physics (quant-ph); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.12470 [pdf]
Quantum(2023)·15 citations
10
[Submitted on 25 Jul 2022] (cross-list from hep-ph)
Jet-medium photons as a probe of parton dynamics
Rouzbeh Modarresi Yazdi🇨🇦 · Shuzhe Shi🇺🇸 · Charles Gale🇨🇦 · Sangyong Jeon🇨🇦
Photons resulting from jet-medium interactions offer the opportunity of studying the evolving quark distribution in a heavy ion collision. The spectra of jet-medium photons is presented within the JETSCAPE framework for two different energy loss models, MARTINI and CUJET. Jet-medium photons can contribute significantly to the spectrum of direct photons in the intermediate $p_{T}$ range.
Comments:
Presented at the XXIXth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions (Quark Matter 2022)
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.12513 [pdf]
Acta Phys.Polon.Supp.(2023)·7 citations
11
[Submitted on 25 Jul 2022] (cross-list from hep-ph)
Neutrino-induced single pion production and the reanalyzed bubble chamber data
D.F. Tamayo Agudelo🇦🇷 · A. Mariano🇦🇷 · D.E. Jaramillo Arango🇨🇴
In this work we report the calculation of the charged current total and differential cross sections for weak pion-production with neutrinos and antineutrinos, with the final pion-nucleon pair invariant mass $W_{π N} ≲ 2$ GeV. Our results are compared with the recent reanalyzed data from the old bubble chamber experiments, that solved the discrepancy between the ANL and BNL data. We implement a model previously tested for the cuts $W_{π N} < 1.4, 1.6$ Gev which includes explicitly resonances in the first and second resonance regions, within different approaches for the resonances self energy and $\frac{3}{2}$ -vertexes and propagators, a fact not usually analyzed. Our model leans on consistent effective Lagrangians that generate resonant amplitudes together non resonant plus resonant backgrounds. Effects of hadrons finite extension and more energetic resonances corresponding to the emitted pion-nucleon invariant mass in the $1.6 < W_{π N} < 2$ GeV region, are taking into account using appropiate form factors in consistency with previous results on neutral current pion production calculations. Our results reproduce well the reanalysed data without cuts and are compared with another models.
Comments:
Manuscript has been accepted for publication as a Regular Article in Physical Review D. arXiv admin note: text overlap with arXiv:1601.01888 by other authors
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.12549 [pdf]
PRD(2022)·2 citations
12
[Submitted on 26 Jul 2022] (cross-list from hep-th)
New developments in relativistic magnetohydrodynamics
Koichi Hattori🇨🇳 · Masaru Hongo🇯🇵 · Xu-Guang Huang🇨🇳
Relativistic magnetohydrodynamics (RMHD) provides an extremely useful description of the low-energy long-wavelength phenomena in a variety of physical systems from quark-gluon plasma in heavy-ion collisions to matters in supernovas, compact stars, and early universe. We review the recent theoretical progresses of RMHD, such as a formulation of RMHD from the perspective of magnetic flux conservation using the entropy-current analysis, the nonequilibrium statistical operator approach applied to quantum electrodynamics, and the relativistic kinetic theory. We discuss how the transport coefficients in RMHD are computed in kinetic theory and perturbative quantum field theories. We also explore the collective modes and instabilities in RMHD with a special emphasis on the role of chirality in a parity-odd plasma. We also give some future prospects of RMHD, including the interaction with spin hydrodynamics and the new kinetic framework with magnetic flux conservation.
Comments:
103 pages, 9 figures. Invited review for Symmetry
Subjects:
High Energy Physics — Theory (hep-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Plasma Physics (physics.plasm-ph)
arXiv:
2207.12794 [pdf]
Symmetry(2022)·53 citations
13
[Submitted on 11 Jul 2022] (cross-list from cs.LG)
Efficient Learning of Accurate Surrogates for Simulations of Complex Systems
A. Diaw · M. McKerns · I. Sagert · L. G. Stanton · M. S. Murillo
Machine learning methods are increasingly used to build computationally inexpensive surrogates for complex physical models. The predictive capability of these surrogates suffers when data are noisy, sparse, or time-dependent. As we are interested in finding a surrogate that provides valid predictions of any potential future model evaluations, we introduce an online learning method empowered by optimizer-driven sampling. The method has two advantages over current approaches. First, it ensures that all turning points on the model response surface are included in the training data. Second, after any new model evaluations, surrogates are tested and "retrained" (updated) if the "score" drops below a validity threshold. Tests on benchmark functions reveal that optimizer-directed sampling generally outperforms traditional sampling methods in terms of accuracy around local extrema, even when the scoring metric favors overall accuracy. We apply our method to simulations of nuclear matter to demonstrate that highly accurate surrogates for the nuclear equation of state can be reliably auto-generated from expensive calculations using a few model evaluations.
Comments:
13 pages, 6 figures, submitted to Nature Machine Intelligence
Subjects:
Machine Learning (cs.LG); Nuclear Theory (nucl-th); Computational Physics (physics.comp-ph); Data Analysis, Statistics and Probability (physics.data-an); Plasma Physics (physics.plasm-ph)
arXiv:
2207.12855 [pdf]
1 citation
14
[Submitted on 26 Jul 2022] (cross-list from hep-ph)
$X$ and $Z_{cs}$ in $B^{+} \to J / ψ ϕ K^{+}$ as $s$ -wave threshold cusps and alternative spin-parity assignments to $X (4274)$ and $X (4500)$
Xuan Luo (Anhui University)🇨🇳 · Satoshi X. Nakamura (Univ. of Science and Technology of China)🇨🇳
Recent LHCb's amplitude analysis on $B^{+} \to J / ψ ϕ K^{+}$ suggests the existence of exotic $X$ and $Z_{cs}$ hadrons, based on an assumption that Breit-Wigner resonances describe all the peak structures. However, all the peaks and also dips in the spectra are located at relevant meson-meson thresholds where threshold kinematical cusps might cause such structures. This points to the importance of an independent amplitude analysis with due consideration of the kinematical effects, and this is what we do in this work. Our model fits well $J / ψ ϕ$ , $J / ψ K^{+}$ , and $K^{+} ϕ$ invariant mass distributions simultaneously, demonstrating that all the $X$ , $Z_{cs}$ , and dip structures can be well described with the ordinary $s$ -wave threshold cusps. Spin-parity of the $X (4274)$ and $X (4500)$ structures are respectively $0^{-}$ and $1^{-}$ from our model, as opposed to $1^{+}$ and $0^{+}$ from the LHCb's. With all relevant threshold cusps considered, the number of fitting parameters seems to be significantly reduced. The LHCb data requires $D_{s}^{(*)} D ˉ^{*}$ scattering lengths in our model to be consistent with zero, disfavoring $D_{s}^{(*)} D ˉ^{*}$ molecule interpretations of $Z_{cs} (4000)$ and $Z_{cs} (4220)$ and, via the SU(3) relation, being consistent with previous lattice QCD results.
Comments:
10 pages, 6 figures, 1 table; v3: minor corrections, matches published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2207.12875 [pdf]
PRD(2023)·9 citations
15
[Submitted on 26 Jul 2022] (cross-list from gr-qc)
Charged quark stars in $f (R, T)$ gravity
Juan M. Z. Pretel🇧🇷 · Takol Tangphati🇹🇭 · Ayan Banerjee🇿🇦 · Anirudh Pradhan🇮🇳
Recent advances in nuclear theory combined with new astrophysical observations have led to the need for specific theoretical models that actually apply to phenomena on dense-matter physics. At the same time, quantum chromodynamics (QCD) predicts the existence of non-nucleonic degrees of freedom at high densities in neutron-star matter, such as quark matter. Within a confining quark matter model, which consists of homogeneous, neutral 3-flavor interacting quark matter with $O (m_{s}^{4})$ corrections, we study the structure of compact stars made of a charged perfect fluid in the context of $f (R, T)$ gravity. The system of differential equations that describe the structure of charged compact stars have been derived and solved numerically for a gravity model with $f (R, T) = R + 2 β T$ . For simplicity, we assume that the charge density is proportional to the energy density, namely, $ρ_{ch} = α ρ$ . It is demonstrated that matter-geometry coupling constant $β$ and the charge parameter $α$ affect the total gravitational mass and the radius of the star.
Comments:
10 pages, 6 figures. To appear in Chinese Physics C
Subjects:
General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2207.12947 [pdf]
CPC(2022)·46 citations
16
[Submitted on 26 Jul 2022] (cross-list from hep-ph)
Compton scattering for photon and gluon in fixed-target collisions at AFTER@LHC
Gongming Yu🇨🇳 · Runlong Liu🇨🇳 · Yanbing Cai🇨🇳 · Quangui Gao🇨🇳 · Qiang Hu🇨🇳
We calculate the Compton scattering for photon and gluon with the Klein-Nishina formula in fixed-target collisions by using the proton and lead beams at AFTER@LHC. In these collisions, we can investigate the particular case of Compton scattering at the partonic level, such as $γ q \to q γ$ , $γ q \to q g$ , $g q \to q γ$ , and $g q \to q g$ , that can help to check of the equivalent-photon approximation and understand the dynamics of hadron collisions at high energies, as well as probe the inner hadron structure.
Comments:
5 pages, 2 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.13089 [pdf]
0 citations

Affiliations

first authorsco-authorsvia INSPIRE