Nuclear Theory·nucl-th

Wednesday·September 13, 2023

11 papers—5 primary·6 cross-listed

01
[Submitted on 11 Sept 2023]
Entropy current and entropy production in relativistic spin hydrodynamics
Francesco Becattini🇮🇹 · Asaad Daher🇵🇱 · Xin-Li Sheng🇮🇹
We use a first-principle quantum-statistical method to derive the expression of the entropy production rate in relativistic spin hydrodynamics. We show that the entropy current is not uniquely defined and can be changed by means of entropy-gauge transformations, much the same way as the stress-energy tensor and the spin tensor can be changed with pseudo-gauge transformations. We show that the local thermodynamic relations, which are admittedly educated guesses in relativistic spin hydrodynamics inspired by those at global thermodynamic equilibrium, do not hold in general and they are also non-invariant under entropy-gauge transformations. Notwithstanding, we show that the entropy production rate is independent of those transformations and we provide a universally applicable expression, extending that known in literature, from which one can infer the dissipative parts of the energy momentum and spin tensors.
Comments:
14 pages with 2 figures. Comments are welcome
Subjects:
Nuclear Theory (nucl-th); Statistical Mechanics (cond-mat.stat-mech); High Energy Physics — Theory (hep-th)
arXiv:
2309.05789 [pdf]
PLB(2024)·48 citations
02
[Submitted on 12 Sept 2023]
Exploring Short-Range Correlations in Symmetric Nuclei: Insights into Contacts and Entanglement Entropy
Wei Kou🇨🇳 · Jingxuan Chen🇨🇳 · Xurong Chen🇨🇳
The Short-Range Correlations between nucleons in nuclei is regarded as a complex system. We investigate the relationship between the orbital entanglement entropy of SRCs $S_{ij}$ in nuclear structures and Tan contact $c_{ij}$ , and find that the orbital entanglement entropies and Tan contacts corresponding to proton-proton SRC pairs and neutron-proton SRC pairs in nuclei demonstrate a scaling relation. More specifically, the proportionality of entanglement entropy between proton-proton pairs and neutron-proton pairs is directly related to the ratio of nuclear contacts within the atomic nucleus, demonstrating an approximate ratio of 2.0. Our research suggests that this scaling relationship should hold true for all symmetric nuclei, furthermore, we offer a possible explanation for this phenomenon.
Comments:
8 pages, 5 figures, 1 table, accepted by PLB
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2309.05909 [pdf]
PLB(2024)·7 citations
03
[Submitted on 12 Sept 2023]
Extracting Kinetic Freeze-out Properties in High Energy Collisions Using a Multi-source Thermal Model
Jia-Yu Chen🇨🇳 · Mai-Ying Duan🇨🇳 · Fu-Hu Liu🇨🇳 · Khusniddin K. Olimov🇺🇿
We study the transverse momentum ( $p_{T}$ ) spectra of neutral pions and identified charged hadrons produced in proton--proton ( $pp$ ), deuteron--gold ( $d$ --Au), and gold--gold (Au--Au) collisions at the center of mass energy $s_{N N} = 200$ GeV. The study is made in the framework of a multi-source thermal model used in the partonic level. It is assumed that the contribution to the $p_{T}$ -value of any hadron comes from two or three partons with an isotropic distribution of the azimuthal angle. The contribution of each parton to the $p_{T}$ -value of a given hadron is assumed to obey any one of the standard (Maxwell-Boltzmann, Fermi-Dirac, and Bose-Einstein) distributions with the kinetic freeze-out temperature and average transverse flow velocity. The $p_{T}$ -spectra of the final-state hadrons can be fitted by the superposition of two or three components. The results obtained from our Monte Carlo method are used to fit the experimental results of the PHENIX and STAR Collaborations. The results of present work serve as a suitable reference baseline for other experiments and simulation studies.
Comments:
18 pages, 8 figures. Advances in High Energy Physics, accepted
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2309.05923 [pdf]
Adv.High Energy Phys.(2024)·3 citations
04
[Submitted on 12 Sept 2023]
Nuclear ground-state properties probed by the relativistic Hartree-Bogoliubov approach
Zi Xin Liu · Yi Hua Lam · Ning Lu · Peter Ring
Using the relativistic Hartree-Bogoliubov framework with separable pairing force coupled with the latest covariant density functionals, i.e., PC-L3R, PC-X, DD-PCX, and DD-MEX, we systematically explore the ground-state properties of all isotopes of Z=8-110. These properties consist of the binding energies, one- and two-neutron separation energies ( $S_{n}$ and $S_{2n}$ ), root-mean-square radius of matter, of neutron, of proton, and of charge distributions, Fermi surfaces, ground-state spins and parities. We then predict the edges of nuclear landscape and bound nuclei for the isotopic chains from oxygen (Z=8) to darmstadtium (Z=110) based on these latest covariant density functionals. The number of bound nuclei predicted by PC-L3R, PC-X, DD-PCX, and DD-MEX, are 9004, 9162, 6799, and 7112, respectively. The root-mean-square deviations of $S_{n}$ ( $S_{2n}$ ) yielded from PC-L3R, PCX, DD-PCX, and DD-MEX are 0.962 (1.300) MeV, 0.920 (1.483) MeV, 0.993 (1.753) MeV, and 1.010 (1.544) MeV, respectively. The root-mean-square deviations of charge radius distributions of comparing the available experimental values with the theoretical counterparts resulted from PC-L3R, PC-X, DD-PCX, and DD-MEX are 0.035 fm, 0.037 fm, 0.035 fm, and 0.034 fm, respectively. We notice pronounced differences between the empirical and theoretical root-mean-square radii of neutron at nuclei near the neutron drip line of the Mg, Ca, and Kr isotopic chains, suggesting the possible existence of the halo or giant halo phenomena.
Comments:
Finalized version, 472 pages (arXiv version), 11 main figures (75 subfigures, colorblind-friendly colors), 6 tables, accepted on 18 December 2023 and to appear at Atomic Data and Nuclear Data Tables, data availability: https://github.com/lamyihua/nuclear-ground-state-properties
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2309.06371 [pdf]
Atom.Data Nucl.Data Tabl.(2024)·11 citations
05
[Submitted on 12 Sept 2023]
Early time dynamics far from equilibrium via holography
Matthias Kaminski🇺🇸 · Casey Cartwright🇺🇸 · Marco Knipfer🇺🇸 · Michael F. Wondrak🇳🇱 · Björn Schenke🇺🇸 · Marcus Bleicher🇩🇪
We investigate the early time dynamics of heavy ion collisions studying the time evolution of the energy-momentum tensor as well as energy-momentum correlations within a uniformly thermalizing holographic QGP. From these quantities, we suggest a far-from equilibrium definition of shear viscosity, which is a crucial property of QCD matter as it significantly determines the generation of elliptic flow already at early times. During an exemplary initial heating phase of the holographic QGP the shear viscosity of entropy density ratio decreases down to 60%, followed by an overshoot to 110% of the near-equilibrium value, $η / s = 1/ (4 π)$ . Implications for the QCD QGP are discussed. Subsequently, we consider a holographic QGP which is Bjorken-expanding. Its energy-momentum tensor components have a known hydrodynamic attractor to which all time evolutions collapse independent of the initial conditions. Based on this, we propose a definition for a far from equilibrium speed of sound, and analytically compute its hydrodynamic attractor. Subjecting this Bjorken-expanding plasma to an external magnetic field and an axial chemical potential, we study the chiral magnetic effect far from equilibrium.
Comments:
7 pages, 4 figures, proceedings of the 11th International Conference on Hard and Electromagnetic Probes of High Energy Nuclear Collisions (Hard Probes 2023)
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Experiment (nucl-ex)
arXiv:
2309.06435 [pdf]
PoS(2024)·1 citation
06
[Submitted on 11 Sept 2023] (cross-list from hep-ph)
Magnetic and density effects on the nucleon axial coupling
C. A. Dominguez🇿🇦 · M. Loewe🇿🇦 · C. Villavicencio🇨🇱 · R. Zamora🇨🇱
Using appropriate QCD finite energy sum rules, we discuss the influence of an external magnetic field and baryonic density on the axial-vector coupling constant $g_{A}$ . This scenario corresponds to a magnetar environment. We found that $g_{A}$ decreases both as function of the magnetic field strength and the baryonic density. It turns out that at the nuclear density $ρ_{0}$ the axial-vector coupling takes the value $g_{A}^{*} \approx 0.92$ . Although $g_{A}$ decreases in general with the magnetic field intensity, $g_{A}^{*}$ does not change in a relevant way with the magnetic field.
Comments:
6 pages, 2 figures. Talk given at QCD2023, Montpellier
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2309.05807 [pdf]
1 citation
07
[Submitted on 12 Sept 2023] (cross-list from gr-qc)
Impact of modified gravity theory on neutron star and nuclear matter properties
Naosad Alam🇮🇳 · Subrata Pal🇮🇳 · A. Rahmansyah🇮🇩 · A. Sulaksono🇮🇩
New observational data, measured with a high degree of accuracy, of compact isolated neutron stars and binary stars in gravitational wave remnants have the potential to explore the strong field gravity. Within the framework of energy-momentum squared gravity (EMSG) theory we study its impact on several properties of neutron stars and plausible modifications from the predictions of general relativity. Based on a representative set of relativistic nuclear mean field models, non-relativistic Skyrme-Hartree-Fock models and microscopic calculations, we show deviations of neutron star mass-radius sequence in EMSG theory as compared to general relativity. The variation in the effective nuclear equation of state in EMSG, results in distinct magnitudes in the reduced pressure, speed of sound, and maximum compactness at the center of neutron stars. We perform extensive correlation analysis of the nuclear model parameters with the neutron star observables in light of the new observational bounds. Perceptible modifications in the correlations are found in the models of gravity that provide different estimates of the slope and curvature of nuclear matter symmetry energy. The available neutron star data however do not impose stringent enough constraints for clear evidence of deviations from general relativity.
Comments:
16 pages, 9 figures, Version to appear in PRD
Subjects:
General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2309.06022 [pdf]
PRD(2024)·19 citations
08
[Submitted on 12 Sept 2023] (cross-list from astro-ph.HE)
Neutrinos and Heavy Element Nucleosynthesis
Xilu Wang · Rebecca Surman
This chapter discusses three nucleosynthesis processes involved in producing heavy nuclei beyond the iron group that are influenced or shaped by neutrino interactions: the v process, the vp process and the r process. These processes are all related to explosive events involving compact objects, such as core-collapse supernovae and binary neutron star mergers, where an abundant amount of neutrinos are emitted. The interactions of the neutrinos with nucleons and nuclei through both charged-current and neutral-current reactions play a crucial role in the nucleosynthesis processes. During the propagation of neutrinos inside the nucleosynthesis sites, neutrinos may undergo flavor oscillations that can also potentially affect the nucleosynthesis yields. Here we provide a general overview of the possible effects of neutrinos and neutrino flavor conversions on these three heavy-element nucleosynthesis processes.
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2309.06043 [pdf]
In: Tanihata, I., Toki, H., Kajino, T. (e…·8 citations
09
[Submitted on 12 Sept 2023] (cross-list from hep-ph)
Exploring Anisotropic flow via the Boltzmann Transport Equation Employing the Tsallis Blast Wave Description at LHC energies
Aviral Akhil🇮🇳 · Swatantra Kumar Tiwari🇮🇳
Anisotropic flows $i . e .$ azimuthal anisotropies in particle production are one of the important probes in characterizing the properties of the strongly interacting matter created in the relativistic heavy-ion collisions. These observables are sensitive to both the transport properties as well as the equation of state (EOS) of Quantum Chromodynamics (QCD) matter. We have adopted the Boltzmann transport equation (BTE) in the relaxation time approximation (RTA) to describe the experimental data for harmonic flows such as elliptic flow ( $v_{2}$ ), triangular flow ( $v_{3}$ ), quadrangular flow ( $v_{4}$ ) obtained in heavy-ion collisions at Large Hadron Collider (LHC) energies. In this analysis, we have used Tsallis statistics as an initial distribution and the Tsallis Blast wave (TBW) description is used as the equilibrium distribution function while describing the evolution of the particle production in BTE. We have fitted the transverse momentum spectra, $v_{2}$ , $v_{3}$ , and $v_{4}$ of identified hadrons such as pion, kaon, and proton for Pb-Pb and Xe-Xe collisions at the LHC energies of $s_{N N}$ = 5.02 TeV and $s_{N N}$ = 5.44 TeV, respectively for various centralities. Our study offers a comparative analysis between the two distinct collision systems operating at comparable collision energies. The present formulation successfully fits the experimental data for $p_{T}$ -spectra upto $p_{T}$ = 8 GeV and effectively explains the anisotropic flows data upto $p_{T}$ = 10 GeV with a very favourable $χ^{2} / n df$ . We observe that the average transverse flow velocity ( $< β_{r} >$ ) and the kinetic freeze-out temperature ( $T$ ) extracted in our analysis decrease as we go towards the peripheral collisions. The azimuthal modulation amplitudes ( $ρ_{a}$ ) exhibit an increasing pattern as one moves from central to peripheral collisions in both the Pb-Pb and Xe-Xe nuclei interactions.
Comments:
16 pages, 10 figures, Published version of the article
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2309.06128 [pdf]
J.Phys.G(2024)·12 citations
10
[Submitted on 12 Sept 2023] (cross-list from hep-ph)
Assumption Breakdown in Radiative Energy Loss
Coleridge Faraday🇿🇦 · W. A. Horowitz🇿🇦
We show that an integral assumption in DGLV radiative energy loss - the large formation time assumption - is violated at high- $p_{T}$ for phenomenologically relevant parameters. We further investigate the phenomenological impact of placing a new kinematic bound on the radiated gluon transverse momentum, which ensures that there are no contributions to the energy loss from regions of parameter space that violate the large formation time assumption. We find that this places a large sensitivity on the exact kinematic cutoff used, similar to the known collinear cutoff sensitivity, indicating the theoretical need for a rederivation of DGLV radiative energy with the large formation time assumption relaxed in order to make rigorous predictions. We additionally find that this large formation time cutoff dramatically reduces the size of a short pathlength correction to the DGLV radiative energy loss, which is of phenomenological interest in predicting suppression in small $p + A$ systems. We compute the phenomenological predictions utilizing this large formation time cutoff in both $p + A$ and $A + A$ collisions at the LHC, in a convolved radiative and elastic energy loss model.
Comments:
Contribution to SAIP 2023, 6 pages, 2 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2309.06246 [pdf]
6 citations
11
[Submitted on 12 Sept 2023] (cross-list from physics.med-ph)
155Tb production by cyclotrons: what level of 155Gd enrichment allows clinical applications?
Francesca Barbaro · Luciano Canton · Nikolay Uzunov · Laura De Nardo · Laura Melendez-Alafort
BACKGROUND: 155Tb represents a potentially useful radionuclide for diagnostic medical applications, but its production remains a challenging problem. A recent experimental campaign, conducted with low-energy proton beams impinging on a 155Gd target with 91.9% enrichment, demonstrated a significant co-production of 156gTb, a contaminant of great concern since its half-life is comparable to that of 155Tb and its high-energy gamma emissions severely impact on the dose released and on the quality of the SPECT images. Herein, the isotopic purity of the enriched 155Gd target necessary to minimize the co-production of contaminant radioisotopes, in particular 156gTb, was explored using various computational simulations. RESULTS: Starting from the recent data obtained with the 155Gd-enriched target, the co-production of other Tb radioisotopes besides 155Tb has been evaluated using the TALYS code. It was found that 156Gd, with an isotopic content of 5.87%, was the principal contributor to the co-production of 156gTb. The analysis also demonstrated that the maximum amount of 156Gd admissible for 155Tb production with a radionuclidic purity higher than 99% was 1%. A less stringent condition was obtained through computational dosimetry analysis, suggesting that a 2% content of 156Gd in the target can be tolerated to limit the dose increase to the patient below the 10% limit. Moreover, it has been demonstrated that the imaging properties of the produced 155Tb are not severely affected by this level of impurity in the target. CONCLUSIONS: 155Tb can be produced with a quality suitable for medical applications using low-energy proton beams and 155Gd-enriched targets if the 156Gd impurity content does not exceed 2%. Under these conditions, the dose increase due to the presence of contaminant radioisotopes remains below the 10% limit and good quality images, comparable to those of 111In, are guaranteed.
Comments:
40 pages, 9 figures, 5 tables. KEYWORDS:Terbium radioisotopes, 155Tb-production, Theranostics, SPECT imaging, Gadolinium targets, Proton-induced nuclear-reaction calculations, Radioisotopic contaminants effects, Dosimetric calculations, Compton noise in SPECT imaging
Subjects:
physics.med-ph (physics.med-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2309.06250 [pdf]
EJNMMI Physics(2024)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE