Nuclear Theory·nucl-th

Tuesday·March 26, 2024

16 papers—7 primary·9 cross-listed

01
[Submitted on 20 Mar 2024]
Exploring the Big Bang with femtoscopy
Mate Csanad🇭🇺
Exploring the fundamental constituents of the matter around us and in the Universe, as well as their interactions, is among the premier goals of physics. Investigating ultrarelativistic collisions in particle accelerators has delivered answers to these questions many times in the past decades. In this paper we focus on the research aimed at recreating the matter that filled the Universe in the first microsecond after the Big Bang -- but this time in collisions of heavy ions. In particular we discuss the technique called femtoscopy, which provides us a tool to understand the space-time structure of particle creation in heavy-ion collisions. We utilize Levy-stable distributions to investigate this structure and explore its dependence on particle momentum and collision energy.
Comments:
13 pages, 10 figures. Proceedings of the Academia Europaea Annual Conference "Building Bridges 2023". Submitted to European Review
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2403.15477 [pdf]
Eur.Rev.(2024)·0 citations
02
[Submitted on 24 Mar 2024]
Heaven and Earth: Nuclear Astrophysics after GW170817
J. Piekarewicz
The historical detection of gravitational waves from the binary neutron star merger GW170817 is providing fundamental new insights into the astrophysical site for the creation of the heaviest elements in the cosmos and on the equation of state of neutron-rich matter. Shortly after this historical detection, electromagnetic observations of neutron stars together with measurements of the properties of neutron-rich nuclei at terrestrial facilities have placed additional constraints on the dynamics of neutron-rich matter. It is this unique synergy between heaven and earth that is the focus of this article.
Comments:
9 pages and 6 figures. Manuscript submitted to the proceedings of the XLV Symposium on Nuclear Physics in Cocoyoc, Mexico
Subjects:
Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Experiment (nucl-ex)
arXiv:
2403.16154 [pdf]
EPJ Web Conf.(2024)·2 citations
03
[Submitted on 25 Mar 2024]
Illuminating Systematic Trends in Nuclear Data with Generative Machine Learning Models
Jordan M. R. Fox · Kyle A. Wendt
We introduce a novel method for studying systematic trends in nuclear reaction data using generative adversarial networks. Libraries of nuclear cross section evaluations exhibit intricate systematic trends across the nuclear landscape, and predictive models capable of reproducing and analyzing these trends are valuable for many applications. We have developed a predictive model using deep generative adversarial networks to learn trends from the inelastic neutron scattering channel of TENDL for even-even nuclei. The system predicts cross sections based on adding/subtracting particles to/from the target nucleus. It can thus help identify cross sections that break from expected trends and predict beyond the limit of current experiments. Our model can produce good predictions for cross section curves for many nuclides, and it is most robust near the line of stability. We also create an ensemble of predictions to leverage different correlations and estimate model uncertainty. This research marks an important first step in computer generation of nuclear cross-section libraries.
Comments:
New version uploaded after rewriting several sections for clarity and one new figure added
Subjects:
Nuclear Theory (nucl-th); Computational Physics (physics.comp-ph)
arXiv:
2403.16389 [pdf]
1 citation
04
[Submitted on 25 Mar 2024]
Effect of Light Nuclei on Chemical Freeze-out Parameters at RHIC Energies
Ning Yu · Zuman Zhang · Hongge Xu · Minxuan Song
In this study, the chemical freeze-out of hadrons, including light-and strange-flavor particles and light nuclei, produced in Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC), was investigated. Using the thermal-FIST thermodynamic statistical model, we analyzed various particle sets: those inclusive of light nuclei, those exclusive to light nuclei, and those solely comprising light nuclei. We determined the chemical freeze-out parameters at $s_{NN} =$ 7.7--200 GeV and four different centralities. A significant finding was the decrease in the chemical freeze-out temperature $T_{ch}$ with light nuclei inclusion, with an even more pronounced reduction when considering light nuclei yields exclusively. This suggests that light nuclei formation occurs at a later stage in the system's evolution at RHIC energies. We present parameterized formulas that describe the energy dependence of $T_{ch}$ and the baryon chemical potential $μ_{B}$ for three distinct particle sets in central Au+Au collisions at RHIC energies. Our results reveal at least three distinct $T_{ch}$ at RHIC energies correspond to different freeze-out hypersurfaces: a light-flavor freeze-out temperature of $T_{L}$ = 150.2 $\pm$ 6 MeV, a strange-flavor freeze-out temperature $T_{s}$ = 165.1 $\pm$ 2.7 MeV, and a light-nuclei freeze-out temperature $T_{ln}$ = 141.7 $\pm$ 1.4 MeV. Notably, at the Large Hadron Collider (LHC) Pb+Pb 2.76 TeV, the expected lower freeze-out temperature for light nuclei was not observed; instead, the $T_{ch}$ for light nuclei was found to be approximately 10 MeV higher than that for light-flavor hadrons.
Comments:
9 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2403.16548 [pdf]
Nucl.Sci.Tech.(2025)·3 citations
05
[Submitted on 25 Mar 2024]
Limits on an improved action for contact effective field theory in two-body systems
L. Contessi🇫🇷 · M. Pavon Valderrama🇨🇳 · U. van Kolck🇮🇹
We consider a possible resummation of subleading effects in two-body systems with a large scattering length as described by a short-range effective field theory (EFT). In particular, we investigate the consequences of a resummation of part of the range corrections. Explicit calculations of the two-body phase shifts and charge form factor indicate that, except for extreme choices, resummations do not alter the convergence of the EFT expansion and are often beneficial at lowest orders. We have considered the expansion when the regulator cutoff is removed as well as when it is finite, and find that the cutoff is not an important factor for resummations. Our results connect with other works where the partial resummation is induced by potentials with finite cutoffs or interaction ranges.
Comments:
11 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th); Quantum Gases (cond-mat.quant-gas)
arXiv:
2403.16596 [pdf]
PLB(2024)·13 citations
06
[Submitted on 25 Mar 2024]
A neural network approach for two-body systems with spin and isospin degrees of freedom
Chuanxin Wang · Tomoya Naito · Jian Li · Haozhao Liang
We propose an enhanced machine learning method to calculate the ground state of two-body systems. By extending the original method [Naito, Naito, and Hashimoto, Phys. Rev. Research 5, 033189 (2023)], the present method enables consideration of the spin and isospin degrees of freedom by employing a non-fully connected deep neural network and the unsupervised machine learning technique. The validity of this method is verified by calculating the unique bound state of the deuteron.
Comments:
10 pages, 5 figures, 4 tables
Subjects:
Nuclear Theory (nucl-th); Computational Physics (physics.comp-ph); Quantum Physics (quant-ph)
arXiv:
2403.16819 [pdf]
Nucl.Sci.Tech.(2026)·9 citations
07
[Submitted on 25 Mar 2024]
Tuned electron-nucleus resonance as a tool of producing the 229mTh isomer
F. F. Karpeshin
The possibility of refining the energy of the 8.36-eV 229mTh nuclear isomer -- the most likely candidate for the role of a nuclear frequency standard -- by means of resonant optical pumping is discussed. Attention is focused on considering the broadening of the resonance in order to reduce scanning time. The two-photon method proposed exploits the radical broadening of the isomer line due to mixing with the electron transition. This is not burdened with the cross-section reduction, in contrast with internal-conversion-based resonance broadening or intended extra-broadening of the spectral line of a pumping laser. In the case under consideration, according to the calculations, it turns out to be two orders of magnitude more efficient. It is applicable to both ionized and neutral thorium atoms. Realization of the method supposes excitation of the both nucleus and electron shell in the final state.
Comments:
Proceeding of the KVNO-2023 Conference
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2403.16924 [pdf]
Fizika(2024)·0 citations
08
[Submitted on 22 Mar 2024] (cross-list from hep-th)
Scalar field with a time-independent classical source, not trivial after all: from vacuum decay to scattering
Leonardo Tinti🇵🇱 · Arthur Vereijken🇵🇱 · Shahriyar Jafarzade🇵🇱 · Francesco Giacosa🇵🇱
Historically it has been believed that a time-independent classical source has no effect on the scattering of relativistic uncharged field, in contrast with single particle quantum mechanics. In this work we show that the dynamics is not trivial. We solve exactly for the scattering amplitudes and find that a key ingredient is the production of particles from the unstable vacuum, conceptually similar to the Schwinger mechanism. We compute exactly the probabilities for the vacuum to decay in $n$ particles. The time dependence of such probabilities displays interesting properties such as the quantum Zeno effect and in particular has no regime where the exponential decay law is a good approximation. We show that the trivial scattering found in the past is the byproduct of the adiabatic switching of the interaction. In fact, it is not possible to switch off the interaction (adiabatically or otherwise) at distant times and recover the exact results. Finally, this non trivial vacuum behavior is a source of particle production. We argue that such non-perturbative calculations can be phenomenologically relevant for the production processes that are suppressed at the lower orders in perturbation theory, for instance dilaton production in a medium.
Comments:
33 pages, 3 figures
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2403.15531 [pdf]
PRD(2024)·1 citation
09
[Submitted on 22 Mar 2024] (cross-list from hep-ph)
From pole parameters to line shapes and branching ratios
L. A. Heuser🇩🇪 · G. Chanturia🇩🇪 · F.-K. Guo🇨🇳 · C. Hanhart🇩🇪 · M. Hoferichter🇨🇭 · B. Kubis🇩🇪
Resonances are uniquely characterized by their complex pole locations and the corresponding residues. In practice, however, resonances are typically identified experimentally as structures in invariant mass distributions, with branching fractions of resonances determined as ratios of count rates. To make contact between these quantities it is necessary to connect line shapes and resonance parameters. In this work we propose such a connection and illustrate the formalism with detailed studies of the $ρ (770)$ and $f_{0} (500)$ resonances. Based on the line shapes inferred from the resonance parameters along these lines, expressions for partial widths and branching ratios are derived and compared to other approaches in the literature.
Comments:
17 pages, 4 figures, v2 as published in EPJC
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2403.15539 [pdf]
EPJC(2024)·31 citations
10
[Submitted on 22 Mar 2024] (cross-list from hep-ph)
Bottomonium suppression from the three-loop QCD potential
Nora Brambilla🇩🇪 · Tom Magorsch🇩🇪 · Michael Strickland🇺🇸 · Antonio Vairo🇩🇪 · Peter Vander Griend🇺🇸
We compute the suppression of bottomonium in the quark-gluon plasma using the three-loop QCD static potential. The potential describes the spin-averaged bottomonium spectrum below threshold with a less than 1% error. Within potential nonrelativistic quantum chromodynamics and an open quantum systems framework, we compute the evolution of the bottomonium density matrix. The values of the quarkonium transport coefficients are obtained from lattice QCD measurements of the bottomonium in-medium width and thermal mass shift; we additionally include for the first time a vacuum contribution to the dispersive coefficient $γ$ . Using the three-loop potential and the values of the heavy quarkonium transport coefficients, we find that the resulting bottomonium nuclear modification factor is consistent with experimental observations, while at the same time reproducing the lattice measurements of the in-medium width.
Comments:
15 pages, 3 figures, 1 table
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2403.15545 [pdf]
PRD(2024)·21 citations
11
[Submitted on 22 Mar 2024] (cross-list from hep-ph)
Exotic tetraquarks at the HL-LHC with JETHAD: A high-energy viewpoint
Francesco Giovanni Celiberto🇪🇸
We review the semi-inclusive hadroproduction of a neutral hidden-flavor tetraquark with light and heavy quark flavor at the HL-LHC, accompanied by another heavy hadron or a light-flavored jet. We make use of the novel TQHL1.0 determinations of leading-twist fragmentation functions to describe the formation mechanism of a tetraquark state within the next-to-leading order perturbative QCD. This framework builds on the basis of a spin-physics inspired model, taken as a proxy for the lowest-scale input of the constituent heavy-quark fragmentation channel. Then, all parton-to-tetraquark fragmentation functions are consistently obtained via the above-threshold DGLAP evolution in a variable-flavor number scheme. We provide predictions for a series of differential distributions calculated by the hands of the JETHAD method well-adapted to NLL/NLO+ hybrid-factorization studies, where the resummation of next-to-leading energy logarithms and beyond is included in the collinear picture. We provide corroborating evidence that high-energy observables sensitive to semi-inclusive tetraquark emissions at the HL-LHC exhibit a fair stability under radiative corrections as well as MHOU studies. Our analysis constitutes a prime contact point between QCD resummations and the exotic matter.
Comments:
38 pages, 7 figures, 500 references. Invited review article. Chapter II of the review pentalogy "Heavy hadrons with JETHAD: A high-energy viewpoint"
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Theory (hep-th); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2403.15639 [pdf]
Symmetry(2024)·29 citations
12
[Submitted on 23 Mar 2024] (cross-list from cond-mat.stat-mech)
Generalized nonlinear Langevin equation from quantum nonlinear projection operator
Jin Hu🇨🇳
We systematically derive the quantum generalized nonlinear Langevin equation using Morozov's projection operator method. This approach extends the linear Mori-Zwanzig projection operator technique, allowing for the inclusion of nonlinear interactions among macroscopic modes. Additionally, we obtain the quantum generalized Fokker-Planck equation within the Heisenberg picture, which is consistent with Morozov's original formulation. These equations are fundamentally significant in non-equilibrium statistical physics, particularly in scenarios characterized by enhanced fluctuations, such as anomalous transport phenomena near critical points. The quantum nature of the derived generalized Langevin and Fokker-Planck equations is anticipated to provide a more detailed description than their classical equivalents. Specifically, the noise kernel in the quantum generalized Langevin equation is multiplicative, which broadens the applicability beyond Gaussian approximations. Given specific interactions, these equations are expected to be instrumental in investigating critical transport phenomena.
Comments:
The version published in PRD. Title and structure of the article changed to emphasize the key points. Any questions, comments, and criticism are welcome
Subjects:
Statistical Mechanics (cond-mat.stat-mech); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2403.15825 [pdf]
PRD(2024)·3 citations
13
[Submitted on 24 Mar 2024] (cross-list from hep-ph)
Nonstandard interactions of neutrinos with dense matter
Parada T. P. Hutauruk🇰🇷
Nonstandard interaction is expected to be a crucial hint in explaining the experimental data on neutrino scattering off electrons. In this context, the nonstandard interaction vector and axial-vector couplings are needed to be extracted from recent experiments and a few of them are now available in the literature. With these coupling bounds, in this paper, I explore their impacts on the neutrinos interacting with the free electron gas in dense matter. To this end, I compute and predict the neutrino differential cross section and mean free path in dense matter for those existing experimental bounds. Interesting behavior in the neutrino cross sections and mean free path is found for the different nonstandard interaction couplings from different experiment constraints. I also found that the neutrino cross-section and mean free path in the dense matter are very sensitive to values and signs of the nonstandard interaction couplings, leading to different prediction results to the Standard Model cross-section and mean free path as well as their totals, which is given by a sum of the Standard Model and nonstandard interaction.
Comments:
17 pages, 8 figures, 1 table, added the appendix in manuscript
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2403.16061 [pdf]
0 citations
14
[Submitted on 25 Mar 2024] (cross-list from hep-ph)
Effect of Coriolis Force on Electrical Conductivity Tensor for Rotating Hadron Resonance Gas
Nandita Padhan🇮🇳 · Ashutosh Dwibedi🇮🇳 · Arghya Chatterjee🇮🇳 · Sabyasachi Ghosh🇮🇳
We have investigated the influence of the Coriolis force on the electrical conductivity of hadronic matter formed in relativistic nuclear collisions, employing the Hadron Resonance Gas (HRG) model. A rotating matter in the peripheral heavy ion collisions can be expected from the initial stage of quark matter to late-stage hadronic matter. Present work is focused on rotating hadronic matter, whose medium constituents - hadron resonances can face a non-zero Coriolis force, which can influence the hadronic flow or conductivity. We estimate this conductivity tensor by using the relativistic Boltzmann transport equation. In the absence of Coriolis force, an isotropic conductivity tensor for hadronic matter is expected. However, our study finds that the presence of Coriolis force can generate an anisotropic conductivity tensor with three main conductivity components - parallel, perpendicular, and Hall, similar to the effect of Lorentz force at a finite magnetic field. Our study has indicated that a noticeable anisotropy of conductivity tensor can be found within the phenomenological range of angular velocity $Ω = 0.001 - 0.02$ GeV and hadronic scattering radius $a = 0.2 - 2$ fm.
Comments:
17 pages, 8 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2403.16647 [pdf]
PRC(2024)·15 citations
15
[Submitted on 25 Mar 2024] (cross-list from hep-ph)
A novel quark pairing in sQGP induced by the non-Abelian feature of the interaction
Fei Gao · Yi Lu · Yu-Xin Liu
We solve the coupled Dyson-Schwinger equations for quark propagator and quark gluon vertex in the Nambu-Gorkov basis which is widely applied to study the color superconductivity. After considering the non-Abelian feature in the off-diagonal part of quark gluon vertex, we acquire a quark pairing gap in chiral limit above the chiral phase transition temperature $T_{c}$ . The gap persists up to $2 - 3 T_{c}$ and vanishes at higher temperature. Such a quark pairing characterizes the strongly coupled quark gluon plasma phase as a new phase and distinct from the phase with quasi quarks and gluons. Its new features can be disclosed in the heavy ion collision experiments.
Comments:
8 pages, 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2403.16816 [pdf]
2 citations
16
[Submitted on 25 Mar 2024] (cross-list from hep-th)
Hydrodynamic fluctuations and topological susceptibility in chiral magnetohydrodynamics
Arpit Das🇬🇧 · Nabil Iqbal🇬🇧 · Napat Poovuttikul🇹🇭
Chiral magnetohydrodynamics is devoted to understanding the late-time and long-distance behavior of a system with an Adler-Bell-Jackiw anomaly at finite temperatures. The non-conservation of the axial charge is determined by the topological density $E \cdot B$ ; in a classical hydrodynamic description this decay rate can be suppressed by tuning the background magnetic field to zero. However it is in principle possible for thermal fluctuations of $E \cdot B$ to result in a non-conservation of the charge even at vanishing $B$ -field; this would invalidate the classical hydrodynamic effective theory. We investigate this by computing the real-time susceptibility of the topological density at one-loop level in magnetohydrodynamic fluctuations, relating its low-frequency limit to the decay rate of the axial charge. We find that the frequency-dependence of this susceptibility is sufficiently soft as to leave the axial decay rate unaffected, validating the classical hydrodynamic description. We show that the susceptibility contains non-analytic frequency-dependence which is universally determined by hydrodynamic data. We comment briefly on possible connections to the recent formulation of the ABJ anomaly in terms of non-invertible symmetry.
Comments:
revtex, 21+3 pages and 1 figure
Subjects:
High Energy Physics — Theory (hep-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2403.16957 [pdf]
SciPost Phys.(2024)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE