Nuclear Theory·nucl-th

Tuesday·October 17, 2023

14 papers—7 primary·7 cross-listed

01
[Submitted on 13 Oct 2023]
Bounds on the Equation of State from QCD Inequalities and Lattice QCD
Yuki Fujimoto🇺🇸 · Sanjay Reddy🇺🇸
We derive robust bounds on the equation of state (EoS) at finite baryon chemical potential using QCD inequalities and input from recent lattice-QCD calculations of thermodynamic properties of matter at nonzero isospin chemical potential. We use lattice data to deduce an upper bound on the baryon density of the symmetric nuclear matter at a given baryon chemical potential and a lower bound on the pressure as a function of the energy density. We also use constraints from perturbative calculations of the QCD EoS at high density derived in earlier work and causality to delineate robust bounds on the EoS of isospin symmetric matter at densities relevant to heavy-ion collisions.
Comments:
12 pages, 10 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2310.09427 [pdf]
PRD(2024)·31 citations
02
[Submitted on 14 Oct 2023]
Accuracy of the mean-field theory in describing ground-state properties of light nuclei
Yu-Ting Rong
The relativistic mean-field model, augmented with three types of center-of-mass corrections and two types of rotational corrections, is employed to investigate the ground-state properties of helium, beryllium, and carbon isotopes. The efficacy of the mean-field approach in describing the binding energies, quadrupole deformations, root-mean-square charge radii, root-mean-square matter radii, and neutron skins of these light nuclei is evaluated. By averaging the binding energies obtained from six selected effective interactions, a mass-dependent behavior of the mean-field approximation is elucidated. The findings from radii reveal that, unlike in heavy nuclei, the exchange terms of the center-of-mass correction play an indispensable role in accurately describing the radii of light nuclei. The mean-field approximation, when augmented with center-of-mass and rotational corrections, effectively reproduces the energies and radii of light nuclei. However, due to the absence of many-body correlations between valence neutrons, the mean-field approximation falls short in describing the deformations and shell evolutions of the helium and beryllium isotopic chains.
Comments:
14 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2310.09476 [pdf]
PRC(2023)·12 citations
03
[Submitted on 14 Oct 2023]
Microscopic derivation of transition-state theory for complex quantum systems
K. Hagino · G.F. Bertsch
The decay of quantum complex systems through a potential barrier is often described with transition-state theory, also known as RRKM theory in chemistry. Here we derive the basic formula for transition-state theory based on a generic Hamiltonian as might be constructed in a configuration-interaction basis. Two reservoirs of random Hamiltonians from Gaussian orthogonal ensembles are coupled to intermediate states representing the transition states at a barrier. Under the condition that the decay of the reservoirs to open channels is large, an analytic formula for reaction rates is derived. The transition states act as independent Breit-Wigner resonances which contribute additively to the total transition probability, as is well known for electronic conductance through resonant tunneling states. It is also found that the transition probability is independent of the decay properties of the states in the second reservoir over a wide range of decay widths.
Comments:
6 pages, 1 figure
Subjects:
Nuclear Theory (nucl-th); Statistical Mechanics (cond-mat.stat-mech); physics.chem-ph (physics.chem-ph); Quantum Physics (quant-ph)
arXiv:
2310.09537 [pdf]
J.Phys.Soc.Jap.(2024)·5 citations
04
[Submitted on 14 Oct 2023]
The extraction of higher-order radial moments of nuclear charge density from muonic atom spectroscopy
Hui Hui Xie · Jian Li · Haozhao Liang
Muonic atom transitions have been measured for almost all stable nuclei to extract nuclear structure properties, including nuclear charge radii and quadrupole moment. To investigate the possibilities of extracting higher-order radial moments of nuclear charge density %what kind of information of nuclear charge distribution can be extracted precisely from muonic atom spectroscopy, a theory-to-theory benchmark analysis based on a model-independent density distribution, i.e., the Fourier-Bessel series expansion instead of two-parameter Fermi distribution, is performed by taking $^{208}$ Pb as an example, where nuclear charge density obtained from the relativistic continuum Hartree-Bogoliubov calculation is used as the benchmark. It is found that the extractions of the higher-order moments, i.e., the fourth and sixth moments in addition to the second moment are feasible with high accuracy. Moreover, the charge form factor in the low- $q$ region can also be well extracted.
Comments:
8 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2310.09546 [pdf]
PRC(2024)·6 citations
05
[Submitted on 14 Oct 2023]
Triaxiality dynamics of quadrupole excitation in even-even heavy nuclei
M. S. Nadirbekov · O.A. Bozarov · S.N. Kudiratov
In the framework free triaxiality model branching ratio reduced E2-transitions probabilities are studied for the full region changes of the triaxiality parameter. The variables of quadrupole deformations $β_{2}$ and $γ$ are dynamic. The Davidson potential for $β_{2}$ and $γ$ variables was being used. In the free triaxiality model the energy levels was being obtained by taking into account the high-order terms of the rotational energy operator series, which leads energy levels of ground-state-band, $β$ - and $γ$ -bands to improve considerably the agreement of the results with experimental data. The quadrupole moment of the nucleus expressed in terms of two internal quadrupole moments: $Q_{0}$ is quadrupole moment about the symmetry axis, $Q_{2}$ is the measure of the shape asymmetry about the symmetry axis. The intra/inter-band reduced E2-transition probabilities ground-state-band, $β$ - and $γ$ -bands are being presented and are being expressed in terms of four parameters: $μ_{β_{2}}$ , $μ_{γ}$ , $γ_{0}$ and $Q_{0}$ . The influence of $γ$ -oscillations to the reduced probabilities of E2-transitions takes into account are numerically. The sensitivity of the intra-/inter-band reduced E2-transition probabilities to the triaxiality parameter was analyzed.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2310.09556 [pdf]
IJMPE(2024)·1 citation
06
[Submitted on 16 Oct 2023]
The effect of electric and chiral magnetic conductivities on azimuthally fluctuating electromagnetic fields and observables in isobar collisions
Irfan Siddique🇨🇳 · Uzma Tabassam🇵🇰
We study the space-time evolution of electromagnetic fields along with the azimuthal fluctuations of these fields and their correlation with the initial matter geometry specified by the participant plane in the presence of finite electric $(σ)$ and chiral magnetic $(σ_{χ})$ conductivities in Ru+Ru and Zr+Zr collisions at $s_{N N} = 200$ GeV. We observe the partially asymmetric behavior of the spatial distributions of the electric and magnetic fields in a conducting medium when compared to the Lienard-Wiechert (L-W) solutions, and deceleration of the decay of the fields is observed in both isobar collisions. While studying the correlation between the magnetic field direction and the participant plane, we see the sizeable suppression of the correlation in the presence of finite conductivities when compared to the L-W case, reflecting the importance of taking into account the medium properties such as conductivities while calculating the magnetic field induced observable quantities.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Theory (hep-th)
arXiv:
2310.10086 [pdf]
PRC(2024)·3 citations
07
[Submitted on 16 Oct 2023]
The $nnn$ and $ppp$ correlation functions
A. Kievsky · E. Garrido · M. Viviani · L.E. Marcucci · L. Serksnyte · R. Del Grande
Scattering experiments with three free nucleons in the ingoing channel are extremely challenging in terrestrial laboratories. Recently, the ALICE Collaboration has successfully measured the scattering of three protons indirectly, by using the femtoscopy method in high-energy proton-proton collisions at the Large Hadron Collider. In order to establish a connection with current and future measurements of femtoscopic three-particle correlation functions, we analyse the scenarios involving $nnn$ and $ppp$ systems using the hyperspherical adiabatic basis. The correlation function is a convolution of the source function and the corresponding scattering wave function. The finite size of the source allows for the use of the free scattering wave function in most of the adiabatic channels except the lowest ones. The scattering wave function has been computed using two different potential models: $(i)$ a spin-dependent Gaussian potential with parameters fixed to reproduce the scattering length and effective range and $(ii)$ the Argonne $v_{18}$ nucleon-nucleon interaction. Moreover, in the case of three protons, the Coulomb interaction has been considered in its hypercentral form. The results presented here have to be considered as a first step in the description of three-particle correlation functions using the hyperspherical adiabatic basis, opening the door to the investigation of other systems, such as the $pp Λ$ system. For completeness, the comparison with the measurement by the ALICE Collaboration is shown assuming different values of the source radius.
Comments:
18 pages, 12 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2310.10428 [pdf]
PRC(2024)·16 citations
08
[Submitted on 13 Oct 2023] (cross-list from hep-ph)
Generalized Gluon Distribution for Quarkonium Dynamics in Strongly Coupled $N = 4$ Yang-Mills Theory
Govert Nijs🇺🇸 · Bruno Scheihing-Hitschfeld🇺🇸 · Xiaojun Yao🇺🇸
We study the generalized gluon distribution that governs the dynamics of quarkonium inside a non-Abelian thermal plasma characterizing its dissociation and recombination rates. This gluon distribution can be written in terms of a correlation function of two chromoelectric fields connected by an adjoint Wilson line. We formulate and calculate this object in $N = 4$ supersymmetric Yang-Mills theory at strong coupling using the AdS/CFT correspondence, allowing for a nonzero center-of-mass velocity $v$ of the heavy quark pair relative to the medium. The effect of a moving medium on the dynamics of the heavy quark pair is described by the simple substitution $T \to γ T$ in agreement with previous calculations of other observables at strong coupling, where $T$ is the temperature of the plasma in its rest frame, and $γ = (1 - v^{2})^{- 1/2}$ is the Lorentz boost factor. Such a velocity dependence can be important when the quarkonium momentum is larger than its mass. Contrary to general expectations for open quantum systems weakly coupled with large thermal environments, the contributions to the transition rates that are usually thought of as the leading ones in Markovian descriptions vanish in this strongly coupled plasma. This calls for new theoretical developments to assess the effects of strongly coupled non-Abelian plasmas on in-medium quarkonium dynamics. Finally, we compare our results with those from weakly coupled QCD, and find that the QCD result moves toward the $N = 4$ strongly coupled result as the coupling constant is increased within the regime of applicability of perturbation theory. This behavior makes it even more pressing to develop a non-Markovian description of quarkonium in-medium dynamics.
Comments:
12 pages, 3 figures; v2: published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2310.09325 [pdf]
PRD(2024)·19 citations
09
[Submitted on 13 Oct 2023] (cross-list from hep-ph)
Parallel scattering, saturation, and generalized Abramovskii-Gribov-Kancheli (AGK) theorem in the EPOS4 framework, with applications for heavy-ion collisions at $s_{N N}$ of 5.02 TeV and 200 GeV
K. Werner🇫🇷
Ultrarelativistic heavy-ion collisions will first realize many nucleon-nucleon scatterings, happening instantaneously and therefore necessarily in parallel, due to the short collision time. An appropriate quantum mechanical tool to treat that problem is S-matrix theory, and it has been known for a long time how to derive a simple geometric probabilistic picture, still widely used, and here the Abramovskii-Gribov-Kancheli (AGK) theorem plays a crucial role. All this is done in a scenario where energy conservation is not taken care of, but this is needed, in particular for Monte Carlo simulations. When introducing energy-momentum sharing properly, the AGK theorem does not apply anymore, nor do simple geometric concepts such as binary scaling. I will discuss this (very serious) problem, and how it can be solved, in the EPOS4 framework. When connecting the multiple Pomeron approach (for parallel scatterings) and perturbative QCD, one is actually forced to implement in a very particular way saturation scales, in order to get an approach free of contradictions. One recovers a generalized AGK theorem (gAGK), valid at large $p_{t}$ (larger than the relevant saturation scales). I discuss how gAGK is related to factorization (in proton-proton scatterings) and binary scaling (in heavy-ion collisions). I will show some applications, using this new approach as an initial condition for hydrodynamical evolutions, for heavy-ion collisions at $s_{N N}$ of 5.02 TeV and 200 GeV, to get some idea about the energy dependence.
Comments:
53 pages, 73 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2310.09380 [pdf]
PRC(2024)·43 citations
10
[Submitted on 13 Oct 2023] (cross-list from hep-ph)
Mass Spectrum of Non-Charmed and Charmed Meson States in Extended Linear-Sigma Model
Azar I. Ahmadov (Baku, Inst. Phys.)🇦🇿 · Azza A. Alshehri (University of Hafr Al Batin, KSA)🇸🇦 · Abdel Nasser Tawfik (Future U. in Egypt and Egyptian Ctr. Theor. Phys., Cairo)🇦🇿
The mass spectrum of different meson particles is generated using an effective Lagrangian of the extended linear-sigma model (eLSM) for scalar and pseudoscalar meson fields and quark flavors, up, down, strange, and charm. Analytical formulas for the masses of scalar, pseudoscalar, vector, and axialvector meson states are derived assuming global chiral symmetry. The various eLSM parameters are analytically deduced and numerically computed. This enables accurate estimations of the masses of sixteen non-charmed and thirteen charmed meson states at vanishing temperature. The comparison of these results to recent compilation of the particle data group (PDG) allows to draw the conclusion that the masses of sixteen non-charmed and thirteen charmed meson states calculated in the eLSM are in good agreement with the PDG. This shows that the eLSM, with its configurations and parameters, is an effective theoretical framework for determining the mass spectra of various non-charmed and charmed meson states, particularly at vanishing temperature.
Comments:
17 pages, 2 tables, no figures to be published in MPDI Particles
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2310.09387 [pdf]
Particles(2024)·3 citations
11
[Submitted on 14 Oct 2023] (cross-list from hep-ph)
One loop reduced QED for massive fermions within an innovative formalism
Victor Miguel Banda Guzmán🇲🇽 · Adnan Bashir🇪🇸 · Luis Albino🇪🇸 · Dania Rodríguez-Tzintzun🇲🇽
We carry out a detailed study of the three-point fermion-photon interaction vertex at one loop order for massive fermions in reduced quantum electrodynamics. This calculation is carried out in arbitrary covariant gauges and space-time dimensions within a recently proposed innovative approach based upon an efficient combination of the first and second order formalisms of quantum electrodynamics. This procedure provides a natural decomposition of the vertex into its components which are longitudinal and transverse to the photon momentum. It also separates the spin and scalar degrees of freedom of a fermion interacting electromagnetically, allowing us to readily establish the gauge-independence of the Pauli form factor and compute it in an expeditious manner. All incoming and outgoing momenta are taken off-shell at the outset. However, we present results for cases of particular kinematic interest whenever required. For the sake of completeness, we also provide expressions for the massive fermion self energy and photon vacuum polarization, verifying known expressions for massless reduced quantum electrodynamics and computing the renormalization constants $Z_{1}$ , $Z_{2}$ and $Z_{3}$ . As we provide general expressions for the computed Green functions, we readily reproduce and confirm the results for standard quantum electrodynamics. Comparing the two cases, we infer that the Pauli form factor for reduced quantum electrodynamics is $8/3$ times that for the standard QED in four dimensions, implying a higher Landé $g$ -factor. We expect our perturbative calculation of the fermion-photon vertex to serve as a guide for any non-perturbative construction of this Green function, invariably required in the Schwinger-Dyson equation studies of the subject.
Comments:
14 pages, 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); cond-mat.mtrl-sci (cond-mat.mtrl-sci); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2310.09670 [pdf]
PRD(2023)·3 citations
12
[Submitted on 15 Oct 2023] (cross-list from hep-ph)
Hadron-quark transition and chiral symmetry restoration at high density
Hiroaki Kouno🇯🇵 · Kouji Kashiwa🇯🇵
A simple phenomenological hybrid hadron-quark model with effective volume effects of baryons and chiral dynamics is investigated. The hybrid EoS naturally connects the low density baryonic matter with the high density quark matter. In the intermediate region, the phase which can not be regarded as pure hadron matter or pure quark matter appears. In this model, there is a possibility that the abrupt first -order like transition to pure quark matter induces the strong chiral symmetry restoration and the speed of sound has a large peak at considerable large density.
Comments:
10 pages, 23 figures. (4 figures and some sentences have been newly added by the replacement. )
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2310.09738 [pdf]
PRD(2024)·8 citations
13
[Submitted on 16 Oct 2023] (cross-list from hep-ph)
Multi-source thermal model describing multi-region structure of transverse momentum spectra of identified particles and parameter dynamics of system evolution in relativistic collisions
Jia-Yu Chen🇨🇳 · Mai-Ying Duan🇨🇳 · Fu-Hu Liu🇨🇳 · Khusniddin K. Olimov🇺🇿
In this article, the multi-region structure of transverse momentum ( $p_{T}$ ) spectra of identified particles produced in relativistic collisions is studied by the multi-component standard distribution (the Boltzmann, Fermi-Dirac, or Bose-Einstein distribution) in the framework of a multi-source thermal model. Results are interpreted in the framework of string model phenomenology in which the multi-region of $p_{T}$ spectra corresponds to the string hadronization in the cascade process of string breaking. The contributions of the string hadronizations from the first-, second-, and third-, i.e., last-generations of string breakings mainly form high-, intermediate-, and low- $p_{T}$ regions, respectively. From the high- to low- $p_{T}$ regions, the extracted volume parameter increases rapidly, and temperature and flow velocity parameters decrease gradually. The multi-region of $p_{T}$ spectra reflects the volume, temperature, and flow velocity dynamics of the system evolution. Due to the successful application of the multi-component standard distribution, this work reflects that the simple classical theory can still play a great role in the field of complex relativistic collisions.
Comments:
15 pages, 7 figures. Indian Journal of Physics, accepted
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2310.10227 [pdf]
Indian J.Phys.(2024)·6 citations
14
[Submitted on 16 Oct 2023] (cross-list from hep-ph)
Nuclear deexcitation simulator for neutrino interactions and nucleon decays of $^{12} C$ and $^{16} O$ based on TALYS
Seisho Abe🇯🇵
Nuclear deexcitation associated with neutrino interactions and nucleon decays has a significant impact on a recent key observable for neutrino detectors: neutron multiplicity. However, most existing neutrino Monte Carlo event generators do not consider this process. For a comprehensive prediction of the neutron multiplicity, a nuclear deexcitation simulator based on TALYS named NucDeEx is developed. NucDeEx can be used for neutrino interactions and nucleon decayes for $^{12} C$ and $^{16} O$ . The author provides the NucDeEx codes and sample codes for applying the NucDeex to widely-used neutrino Monte Carlo event generators, NEUT, NuWro, and GENIE.
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2310.10394 [pdf]
PRD(2024)·14 citations

Affiliations

first authorsco-authorsvia INSPIRE