Nuclear Theory·nucl-th

Tuesday·August 2, 2022

25 papers—15 primary·10 cross-listed

01
[Submitted on 29 Jul 2022]
Light baryon resonances from a coupled-channel study including $KΣ$ photoproduction
Deborah Rönchen🇩🇪 · Michael Döring🇺🇸 · Ulf-G. Meißner🇩🇪 · Chao-Wei Shen🇩🇪
The Jülich-Bonn dynamical coupled-channel approach is extended to include $K Σ$ photoproduction off the proton. Differential cross section and (double) polarization data for $K^{+} Σ^{0}$ and $K^{0} Σ^{+}$ are analysed simultaneously with the pion- and photon-induced production of $π N$ , $η N$ , $K Λ$ , and $K Σ$ final states, totaling more than 67,000 data points for center-of-mass energies $W < 2.4$ GeV. Based on the fit results the spectrum of $N^{*}$ and $Δ$ resonances is extracted in terms of pole positions and residues. We discuss the impact of the $γ p \to K Σ$ channels in detail and investigate the influence of recent polarization data for $η p$ photoproduction.
Comments:
Updated to the published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2208.00089 [pdf]
EPJA(2022)·55 citations
02
[Submitted on 29 Jul 2022]
Neutron $3 s_{1/2}$ occupation change across the stable tin isotopes investigated using isotopic analysis of proton scattering at 295 MeV
Yoshiko Kanada-En'yo
The isotopic systematics of Sn isotopes in the range A=116--124 were investigated by combining the nuclear structure and reaction calculations for the analysis of Sn(p,p) reactions at 295 MeV. The Sn(p,p) reactions were calculated employing relativistic impulse approximation (RIA) with theoretical densities obtained for the Sn isotopes from relativistic Hartree-Bogoliubov (RHB) calculations with the DD-ME2 interaction and nonrelativistic Skyrme Hartree-Fock-Bogoliubov (SHFB) calculations with the SKM* interaction. Calculation using the DD-ME2 density reproduced the experimental data for $^{122}$ Sn(p,p) but overestimated the $^{116}$ Sn(p,p) and $^{118}$ Sn(p,p) cross sections at backward angles. In the isotopic analysis of the cross section ratio $R (σ)$ of $^{122}$ Sn to $^{116}$ Sn, a calculation using the SKM* density reproduced the peak amplitudes of $R (σ)$ obtained from the experimental cross sections, whereas a calculation using the DD-ME2 density did not. The ratio $R (σ)$ was found to be sensitive to the isotopic change of the neutron $3 s_{1/2}$ occupation through the isotopic difference of the surface neutron density around r=4--5 fm. Isotopic analysis indicated that a rapid increase of the $3 s_{1/2}$ occupation from $^{116}$ Sn to $^{122}$ Sn obtained by the DD-ME2 calculation is unlikely. This result derived from the 295 MeV Sn(p,p) cross section data is consistent with the direct measurement of the neutron occupations in Sn isotopes by neutron transfer and pick-up reactions.
Comments:
7 pages, 8 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2208.00104 [pdf]
PRC(2022)·2 citations
03
[Submitted on 30 Jul 2022]
Hydrodynamic simulations of directed flow for light hadrons in Au+Au and isobar collisions $s_{NN} =$ 200 GeV
Jing Jing🇨🇳 · Ze-Fang Jiang🇨🇳 · C. B. Yang🇨🇳 · Ben-Wei Zhang🇨🇳
Using a (3+1)-D hydrodynamic model CLVisc, we study the directed flow ( $v_{1}$ ) of light hadrons produced in Au+Au, Ru+Ru and Zr+Zr collisions at $s_{NN} =$ 200 GeV. The evolution of tilted energy density, pressure gradient and radial flow along the $x$ -direction are systematically investigated. Counter-clockwise tilt of initial fireball is shown to be a vital source of the directed flow for final light hadrons. A good description of directed flow is provided for light hadrons in central and mid-central Au+Au and isobar collisions at RHIC. Our numerical results show a clear system size dependence for light hadron $v_{1}$ across different collision systems. We further study the effect of nuclear structure on the directed flow and find that the $v_{1}$ for light hadrons is insensitive to the nuclei with quadrupole deformation.
Comments:
11 pages, 9 figures, 3 tables, published in Chin. Phys. C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2208.00155 [pdf]
CPC(2023)·6 citations
04
[Submitted on 30 Jul 2022]
Sub-barrier d+ $^{208}$ Pb scattering and sensitivity to nucleon-nucleon interactions
Peng Yin · Weijie Du · Wei Zuo · Xingbo Zhao · James P. Vary
We employ the non-perturbative time-dependent basis function (tBF) approach to solve for the sub-Coulomb barrier scattering of the deuteron projectile on the $^{208}$ Pb target. Specifically, we treat the target as a source of a strong external Coulomb field that induces higher-order effects in electric-dipole excitations of the deuteron projectile including the population of states not accessible through direct electric-dipole transitions from the ground state of the deuteron. We calculate the electric-dipole polarizability of the deuteron and elastic scattering observables for comparison with experimental data. With no adjustable parameters, the tBF approach provides good agreement with experimentally available differential cross-section ratios. The dependence of these measured quantities on nucleon-nucleon interactions is investigated. We also investigate the detailed scattering dynamics and identify characteristics of coherent and incoherent processes.
Comments:
13 figures; 3 tables; Comments are welcome!
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2208.00267 [pdf]
7 citations
05
[Submitted on 30 Jul 2022]
Impact of Symmetry Energy on Sound Speed and Spinodal Decomposition in Dense Neutron-Rich Matter
Nai-Bo Zhang🇨🇳 · Bao-An Li🇺🇸
Using a meta model for nuclear Equation of State (EOS) with its parameters constrained by astrophysical observations and terrestrial nuclear experiments, we examine effects of nuclear EOS especially its symmetry energy \esym term on the speed of sound squared $C_{s}^{2} (ρ)$ and the critical density $ρ_{t}$ where $C_{s}^{2} (ρ_{t})$ vanishes (indicating the onset of spinodal decomposition) in both dense neutron-rich nucleonic matter relevant for relativistic heavy-ion collisions and the cold $n + p + e + μ$ matter in neutron stars at $β$ -equilibrium. Unlike in nucleonic matter with fixed values of the isospin asymmetry $δ$ , in neutron stars with a density dependent isospin profile $δ (ρ)$ determined consistently by the $β$ equilibrium and charge neutrality conditions, the $C_{s}^{2} (ρ)$ almost always show a peak and then vanishes at $ρ_{t}$ . The latter strongly depends on the high-density behavior of \esym if the skewness parameter $J_{0}$ characterizing the stiffness of high-density symmetric nuclear matter (SNM) EOS is not too far above its currently known most probable value of about $- 190$ MeV inferred from recent Bayesian analyses of neutron star observables. Moreover, in the case of having a super-soft \esym that is decreasing with increasing density above about twice the saturation density of nuclear matter, the $ρ_{t}$ is significantly lower than the density where the \esym vanishes (indicating the onset of isospin-separation instability and pure neutron matter formation) in neutron star cores.
Comments:
New discussions added. EPJA in press
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2208.00321 [pdf]
EPJA(2023)·30 citations
06
[Submitted on 31 Jul 2022]
Possible Enhancements of Collective Flow Anisotropy Induced by Uncertainty Relation for Fluid Element
G. G. Matos🇧🇷 · T. Koide🇧🇷 · T. Kodama🇧🇷
In the stochastic formulation of viscous hydrodynamics, the velocity of a fluid element fluctuates satisfying a similar relation to the quantum-mechanical uncertainty relation. Using a non-relativistic toy model, we show that the presence of such a velocity fluctuation increases the local anisotropy of the momentum distributions of produced hadrons, and thus the collective flow parameters such as $v_{2}$ is emphasized.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2208.00452 [pdf]
J.Phys.G(2023)·1 citation
07
[Submitted on 31 Jul 2022]
Quark Matter in the NJL Model with a Vector Interaction and the Structure of Hybrid Stars
G. B. Alaverdyan🇦🇲
The properties of hadron-quark hybrid stars are studied when the quark phase is described in terms of a local SU(3) Nambu--Jona-Lasinio (NJL) model taking into account the contribution of the vector and axial-vector interaction between the quarks, and the hadronic phase, in the relativistic mean field (RMF) model. For different values of the vector coupling constant $G_{V}$ , the equations of state of the quark matter are calculated and the parameters of the hadron-quark phase transition are determined under the assumption that the phase transition takes place in accordance with Maxwell's construction. It is shown that for a larger vector coupling constant, the equation of state of the quark matter will be "stiffer" and the coexistence pressure $P_{0}$ of the phases will be greater. Using the resulting hybrid equations of state, the TOV equations are integrated numerically and the mass and radius of the compact star are determined for different values of the central pressure $P_{c}$ . It is shown that when $G_{V}$ is larger, the maximum mass of the compact star will be larger and thereby, the radius of the configuration with maximum mass will be smaller. Questions of the stability of hybrid stars are also discussed. It is shown that in terms of the model examined here, for all values of the vector coupling constant, a hybrid star with an infinitely small quark core is stable. These results are compared with recent measurements of the mass and radius of the pulsars PSR J0030+0451 and PSR J0740+6620, carried out at the International Space Station with the NASA's Neutron star Interior Composition Explorer (NICER) X-ray telescope. A comparison of the theoretical results with observational data does not exclude the possibility of quark deconfinement in the interiors of compact stars.
Comments:
13 pages, 4 figures, 1 table
Subjects:
Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2208.00466 [pdf]
Astrophysics(2022)·12 citations
08
[Submitted on 31 Jul 2022]
Effect of global momentum conservation on longitudinal flow decorrelation
Pingal Dasgupta🇨🇳 · Han-Sheng Wang🇨🇳 · Guo-Liang Ma🇨🇳
We calculate the longitudinal flow decorrelation coefficients, i.e., $r_{n} (η, η_{r})$ for $n = 2, 3$ , in the presence of hydro-like flow and the global momentum conservation (GMC) constraint. The longitudinal flow decorrelation is weakened due to the GMC constraint. The GMC effect is sensitive to the total number of particles involved in GMC, the average longitudinal momentum, the transverse momentum, and the reference pseudorapidity. Our results of the $r_{2} (η, η_{r A}) / r_{2} (η, η_{r B})$ ratio between two reference pseudorapidity bins are consistent with the experimental measurements. We predict that the modification effect of GMC on longitudinal flow decorrelation is more noticeable at BNL Relativistic Heavy Ion Collider energies than at CERN Large Hadron Collider energies. Our finding provides a new perspective for understanding the longitudinal flow decorrelation in relativistic heavy-ion collisions.
Comments:
13 pages, 6 figures, final published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2208.00468 [pdf]
PRC(2023)·4 citations
09
[Submitted on 31 Jul 2022]
A New Structure in the Deuteron
Misak M. Sargsian🇺🇸 · Frank Vera🇺🇸
We demonstrate that a paradigm shift from considering the deuteron as a system of bound proton and neutron to considering it as a pseudo-vector system in which we observe proton and neutron, results in a possibility of probing a new "incomplete" P-state like structure on the light-front (LF), at extremely large internal momenta, which can be achieved in high energy transfer electro-disintegration of the deuteron. Investigating the deuteron on the light-front, where the vacuum-fluctuations are suppressed, we found that this new structure, together with conventional S- and D- states, is a leading order in transferred energy of the reaction, thus it is not suppressed on the light-front.The incompleteness of the observed P-state results in a violation of angular condition which can happen only if deuteron contains non-nucleonic structures such as $Δ$ $Δ$ , $N^{*} N$ or hidden color components. We demonstrate that experimentally verifiable signatures of "incomplete" P-states are angular anisotropy of LF momentum distribution of the nucleon in the deuteron as well as an enhancement of the tensor polarization strength beyond the S- and D- wave predictions at large internal momenta in the deuteron.
Comments:
Five pages and two figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2208.00501 [pdf]
PRL(2023)·14 citations
10
[Submitted on 1 Aug 2022]
Deformation effects on the surface neutron densities of stable S and Ni isotopes probed by proton elastic scattering via isotopic analysis
Yoshiko Kanada-En'yo
To extract structure information from proton elastic scattering off S isotopes at 320 MeV and Ni isotopes at $E_{p} = 180$ MeV, this study proposes isotopic analyses combining nuclear structure and reaction calculations. The isotonic analysis was repeated on $^{48}$ Ca and $^{50}$ Ti. The structure calculations were performed by using the spherical and deformed Relativistic Hartree--Bogoliubov (RHB) calculations, and the spherical nonrelativistic Skyrme Hartree--Fock--Bogoliubov calculations. The $(p, p)$ reactions were calculated using the relativistic impulse approximation (RIA) assuming the theoretical densities of target nuclei. The RIA calculations using the target densities obtained by the RHB calculation, along with the density-dependent point-coupling interactions reasonably reproduced the $(p, p)$ cross sections in the studied mass number region. The nuclear structure and $(p, p)$ reactions were analyzed in detail; especially, the effects of deformation on the isotopic systematics of the surface densities and $(p, p)$ cross sections were clarified. The deformation effects were found to be essential to describe the isotopic systematics of the experimental $(p, p)$ cross sections. Overall, isotopic and isotonic analyses are useful for extracting the nuclear structure information such as nuclear deformations and single-particle features from proton scattering, enabling sensitive probing of surface densities.
Comments:
13 pages, 19 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2208.00590 [pdf]
1 citation
11
[Submitted on 1 Aug 2022]
Far-from-equilibrium attractor in non-conformal plasmas
Sunil Jaiswal🇮🇳 · Subrata Pal🇮🇳 · Chandrodoy Chattopadhyay🇺🇸 · Lipei Du🇨🇦 · Ulrich Heinz🇺🇸
We study the far-off-equilibrium dynamics of a Bjorken expanding non-conformal system within kinetic theory and hydrodynamics. We show that, in contrast to the conformal case, neither shear nor bulk viscous pressure relax quickly to a non-equilibrium attractor. In kinetic theory an early-time, far-from-equilibrium attractor exists for the scaled longitudinal pressure, driven by the rapid longitudinal expansion of the medium. Second-order dissipative hydrodynamics fails to accurately describe this attractor, but a modified anisotropic hydrodynamic formulation reproduces it and provides excellent agreement with kinetic theory.
Comments:
Contribution to the proceedings of Quark Matter 2022. 6 pages, 3 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2208.00744 [pdf]
Acta Phys.Polon.Supp.(2023)·6 citations
12
[Submitted on 1 Aug 2022]
Ab-initio no-core shell model study of $^{18 - 24}$ Ne isotopes
Chandan Sarma · Praveen C. Srivastava
We report \textit{ab initio} no-core shell model (NCSM) study of $^{18 - 24}$ Ne isotopes for energy spectra, electromagnetic properties, and point-proton radii using three realistic $N N$ interactions. We have used inside nonlocal outside Yukawa (INOY), charge-dependent Bonn 2000 (CDB2K) and the chiral next-to-next-to-next-to-leading order (N $^{3}$ LO) interactions. We are able to reach basis size up to $N_{ma x}$ = 6 for $^{18}$ Ne and $N_{ma x}$ = 4 for the $^{19 - 24}$ Ne isotopes with m-scheme dimensions up to 1.0 $\times$ $1 0^{9}$ in case of $^{24}$ Ne. We observed better results for INOY interaction in terms of the binding energies of ground state (g.s.), and overall all three interactions provide good agreement with the experimental low-energy spectra. Our results for reduced $M 1$ transition strengths and magnetic moments are close to the experimental values. We found that for long-range observables such as the $E 2$ transition strengths, the electric quadrupole moments, and the point-proton radii ( $r_{p}$ ), we need higher $N_{ma x}$ calculations to obtain results comparable to the experimental data. We have observed almost 6 \% increment in the converged $r_{p}$ as we increase the model space from $N_{ma x}$ = 4 to $N_{ma x}$ = 6.
Comments:
19 pages, 9 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2208.00816 [pdf]
J.Phys.G(2023)·14 citations
13
[Submitted on 1 Aug 2022]
Multi-scale evolution of charmed particles in a nuclear medium
JETSCAPE collaboration: W. Fan🇺🇸 · G. Vujanovic🇨🇦 · S. A. Bass🇺🇸 · A. Majumder🇺🇸 · A. Angerami🇺🇸 · R. Arora🇺🇸 · S. Cao🇺🇸 · Y. Chen🇺🇸 · T. Dai🇺🇸 · L. Du🇨🇦 · R. Ehlers🇺🇸 · H. Elfner🇩🇪 and 47 other authors
Parton energy-momentum exchange with the quark gluon plasma (QGP) is a multi-scale problem. In this work, we calculate the interaction of charm quarks with the QGP within the higher twist formalism at high virtuality and high energy using the MATTER model, while the low virtuality and high energy portion is treated via a (linearized) Boltzmann Transport (LBT) formalism. Coherence effect that reduces the medium-induced emission rate in the MATTER model is also taken into account. The interplay between these two formalisms is studied in detail and used to produce a good description of the D-meson and charged hadron nuclear modification factor RAA across multiple centralities. All calculations were carried out utilizing the JETSCAPE framework.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2208.00983 [pdf]
PRC(2023)·28 citations
14
[Submitted on 1 Aug 2022]
Probing flow fluctuations through factorization breaking of harmonic flows in heavy-ion collisions
Piotr Bozek🇵🇱 · Rupam Samanta🇵🇱
We study factorization-breaking coefficients between the momentum dependent and momentum averaged flow vectors to probe flow fluctuations caused by initial-state fluctuations in heavy-ion collision. The coefficients for the flow vector squared and flow magnitude squared could be used for the extraction of flow angle decorrelations. We compare our model results with preliminary experimental data. We also present the predictions for the momentum dependent correlation between mixed flow harmonics.
Comments:
Presented by R. Samanta at Quark Matter 2022 : XXIXth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2208.01015 [pdf]
Acta Phys.Polon.Supp.(2023)·2 citations
15
[Submitted on 1 Aug 2022]
Atlas of Nuclear Isomers -- Second Edition
Swati Garg · Bhoomika Maheshwari · Balraj Singh · Yang Sun · Alpana Goel · Ashok Kumar Jain
We present an updated version of the 2015-Atlas of Nuclear Isomers \cite{jain2015}, compiling and evaluating experimental data for the isomers with half-life $\geq 10$ $ns$ , together with their spectroscopic properties such as excitation-energies, half-lives, decay modes, spins and parities, energies and multipolarities of isomeric transitions, along with the relevant original references in literature. The current version of Atlas presents many re-evaluated half-lives as compared to the 2015 edition, where values were referred to Nuclear Data Sheets publications, when no new data existed. The ENSDF database \cite{Ensdf}, together with the XUNDL \cite{Xundl} and the NUBASE2020 \cite{Kondev2021} databases have been consulted for completeness, yet, data from original papers from journals were considered in the present evaluation, and the NSR bibliographic database \cite{Nsr} has been searched to ensure that this work is as complete and current as possible. Several useful systematic features of nuclear isomers covered in this Atlas have been discussed. Literature cutoff date for the extraction of data is October 31, 2022.
Comments:
To appear in ADNDT
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2208.01028 [pdf]
Atom.Data Nucl.Data Tabl.(2023)·53 citations

Affiliations

first authorsco-authorsvia INSPIRE