Nuclear Theory·nucl-th

Monday·August 30, 2021

12 papers—7 primary·5 cross-listed

01
[Submitted on 26 Aug 2021]
Dynamical model of $ϕ$ meson photoproduction on the nucleon and $^{4} H e$
Sang-Ho Kim🇰🇷 · T.-S. H. Lee🇺🇸 · Seung-il Nam🇰🇷 · Yongseok Oh🇰🇷
We investigate $ϕ$ meson photoproduction on the nucleon and the \nuclide[4]{He} targets within a dynamical model approach based on a Hamiltonian which describes the production mechanisms by the Pomeron-exchange, meson-exchanges, $ϕ$ radiations, and nucleon resonance excitations mechanisms. The final $ϕN$ interactions are included being described by the gluon-exchange, direct $ϕN$ couplings, and the box-diagrams arising from the couplings with $π N$ , $ρN$ , $K Λ$ , and $K Σ$ channels. The parameters of the Hamiltonian are determined by the experimental data of $γ p \to ϕp$ from the CLAS Collaboration. The resulting Hamiltonian is then used to predict the coherent $ϕ$ -meson production on the \nuclide[4]{He} targets by using the distorted-wave impulse approximation. For the proton target, the final $ϕN$ rescattering effects, as required by the unitarity condition, are found to be very weak, which supports the earlier calculations in the literature. For the \nuclide[4]{He} targets, the predicted differential cross sections are in good agreement with the data obtained by the LEPS Collaboration. The role of each mechanism in this reaction is discussed and predictions for a wide range of scattering angles are presented, which can be tested in future experiments.
Comments:
16 pages, REVTeX
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2108.12039 [pdf]
PRC(2021)·19 citations
02
[Submitted on 27 Aug 2021]
Nucleon momentum distribution of $^{56} Fe$ from the axially deformed relativistic mean-field model with nucleon--nucleon correlations
Xuezhi Wang · Qinglin Niu · Jinjuan Zhang · Mengjiao Lyu · Jian Liu · Chang Xu · Zhongzhou Ren
Nucleon momentum distribution (NMD), particularly its high-momentum components, is essential for understanding the nucleon--nucleon ( $N N$ ) correlations in nuclei. Herein, we develop the studies of NMD of $^{56} Fe$ from the axially deformed relativistic mean-field (RMF) model. Moreover, we introduce the effects of $N N$ correlation into the RMF model from phenomenological models based on deuteron and nuclear matter. For the region $k < k_{F}$ , the effects of deformation on the NMD of the RMF model are investigated using the total and single-particle NMDs. For the region $k > k_{F}$ , the high-momentum components of the RMF model are modified by the effects of $N N$ correlation, which agree with the experimental data. Comparing the NMD of relativistic and non-relativistic mean-field models, the relativistic effects on nuclear structures in momentum space are analyzed. Finally, by analogizing the tensor correlations in deuteron and Jastrow-type correlations in nuclear matter, the behaviors and contributions of $N N$ correlations in $^{56} Fe$ are further analyzed, which helps clarify the effects of the tensor force on the NMD of heavy nuclei.
Comments:
12 pages, 10 figures, This article has been published in SCIENCE CHINA Physics, Mechanics & Astronomy(SCPMA), and the original publication is available at www.scichina.com and www.springerlink.com
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2108.12087 [pdf]
SCPMA(2021)·14 citations
03
[Submitted on 27 Aug 2021]
Relativistic nucleon-nucleon potentials in a spin-dependent three-dimensional approach
M. R. Hadizadeh · M. Radin · F. Nazari
The matrix elements of relativistic nucleon-nucleon $(N N)$ potentials are calculated directly from the nonrelativistic potentials as a function of relative $N N$ momentum vectors, without using a partial wave decomposition. To this aim, the quadratic operator relation between the relativistic and nonrelativistic $N N$ potentials is formulated in momentum-helicity basis states. It leads to a single integral equation for the two-nucleon $(2 N)$ spin-singlet state and four coupled integral equations for two-nucleon spin-triplet states, which are solved by an iterative method. Our numerical analysis indicates that the relativistic $N N$ potential obtained using CD-Bonn potential reproduces the deuteron binding energy and neutron-proton elastic scattering differential and total cross-sections with high accuracy.
Subjects:
Nuclear Theory (nucl-th); Computational Physics (physics.comp-ph)
arXiv:
2108.12101 [pdf]
Sci.Rep.(2021)·5 citations
04
[Submitted on 27 Aug 2021]
Super- and hyper-deformation in $^{60}$ Zn, $^{62}$ Zn, and $^{64}$ Ge at high spins
Kenichi Yoshida
Background: The observation of the superdeformed (SD) bands in $^{60, 62}$ Zn indicates that the particle number 30 is a magic particle number, where two and four neutron single-particles are considered to be promoted to the intruder $1 g_{9/2}$ shell. However, the SD-yrast band in $^{62}$ Zn is assigned negative parity. Purpose: I investigate various SD configurations in the rapidly rotating $^{60, 62}$ Zn and $^{64}$ Ge, and attempt elucidating the different roles of the energy gaps at particle numbers 30 and 32. Method: I employ a nuclear energy-density functional (EDF) method: the configuration-constrained cranked Skyrme-Kohn-Sham approach is used to describe the rotational bands near the yrast line. Results: The negative-parity SD bands appear higher in energy than the positive-parity SD-yrast band in $^{60}$ Zn by about 4 MeV, which is indicative of the SD doubly-magic nucleus. However, the energy gap in $^{64}$ Ge is smaller $\sim 2 - 3$ MeV, though the quadrupole deformation of the SD states in $^{64}$ Ge is greater than that of $^{60}$ Zn. The present calculation predicts the occurrence of the hyperdeformed state in $^{60}$ Zn and $^{64}$ Ge at a high rotational frequency $\sim 2.0$ MeV $/ℏ$ due to the occupation of the $h_{11/2}$ shell. Conclusions: An SD-shell gap at particle number 30 and 32 appears at different deformations and the energy gap at particle number 32 is low, which make the SD structures of $^{62}$ Zn unique, where the negative-parity SD states appear lower in energy than the positive-parity one.
Comments:
12 pages, 11 figures; accepted version
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2108.12130 [pdf]
PRC(2022)·4 citations
05
[Submitted on 27 Aug 2021]
Structural and decay properties of nuclei appearing in the $α$ -decay chains of $^{296, 298, 300, 302, 304}$ 120 within the relativistic mean-field formalism
N. Biswal · Nishu Jain · Raj Kumar · A. S. Pradeep · M. Bhuyan
An extensive study of $α$ -decay half-lives for various decay chains of isotopes of $Z$ = 120 is performed within the axially deformed relativistic mean-field (RMF) formalism by employing the NL3, NL3 $^{*}$ , and DD-ME2 parameter set. The structural properties of the nuclei appearing in the decay chains are explored. The binding energy, quadrupole deformation parameter, root-mean-square charge radius, and pairing energy are calculated for the even-even isotopes of $Z$ = 100 $-$ 120, which are produced in five different $α$ -decay chains, namely, $^{296}$ 120 $\to$ $^{260}$ No, $^{298}$ 120 $\to$ $^{262}$ No, $^{300}$ 120 $\to$ $^{264}$ No, $^{302}$ 120 $\to$ $^{266}$ No, and $^{304}$ 120 $\to$ $^{268}$ No. A superdeformed prolate ground state is observed for the heavier nuclei, and gradually the deformation decreases towards the lighter nuclei in the considered decay chains. The RMF results are compared with various theoretical predictions and experimental data. The $α$ -decay energies are calculated for each decay chain. To determine the relative numerical dependency of the half-life for a specific $α$ -decay energy, the decay half-lives are calculated using four different formulas, namely, Viola-Seaborg, Alex-Brown, Parkhomenko-Sobiczewski, and Royer for the above said five $α$ -decay chain. We notice a firm dependency of the half-life on the $α$ -decay formula in terms of $Q_{α}$ -values for all decay chains. Further, the present study also strengthens the prediction for the island of stability in terms of magic number at the superheavy valley in the laboratories.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2108.12148 [pdf]
Mod.Phys.Lett.A(2021)·4 citations
06
[Submitted on 27 Aug 2021]
Fusion cross section of the superheavy $Z$ = 120 nuclei within the relativistic mean-field formalism
Shilpa Rana · Raj Kumar · M. Bhuyan
Present theoretical investigations aim to explore the fusion characteristics of various isotopes of Z=120 within the relativistic mean-field (RMF) formalism. We predict the most suitable projectile-target combination for the synthesis of element Z=120. The microscopic nucleon-nucleon R3Y interaction and the RMF density distributions for targets and projectiles are used to calculate the nuclear interaction potential using the double folding approach. 17 different projectile-target combinations that allow a high $N$ / $Z$ ratio are considered in the present analysis to calculate the capture and/or fusion cross-section of various isotopes of Z=120 within the $ℓ -$ summed Wong formula. Further, the equivalent surface diffusion parameter is estimated to correlate the surface properties interacting nuclei with the fusion cross-section. The four Ti-based reactions with the heaviest available target $^{x}$ Cf, namely, $^{46}$ Ti+ $^{248}$ Cf, $^{46}$ Ti+ $^{249}$ Cf, $^{50}$ Ti+ $^{249}$ Cf, and $^{50}$ Ti+ $^{252}$ Cf, and also $^{54}$ Cr+ $^{250}$ Cm are found to have the most suitable target-projectile combinations for the synthesis of various isotopes Z=120. We also notice that $^{48}$ Ca beams merely provide the required number of protons to synthesize the element with Z=120. We established a correlation among the surface properties of interacting nuclei with the fusion characteristics in terms of the equivalent surface diffusion parameter.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2108.12162 [pdf]
Physical Review C (2021)
07
[Submitted on 27 Aug 2021]
Fusion dynamics of $^{12}$ C+ $^{12}$ C reaction: An astrophysical interest within the relativistic mean-field approach
Shilpa Rana🇮🇳 · Raj Kumar🇮🇳 · M. Bhuyan🇲🇾
The $^{12}$ C+ $^{12}$ C fusion reaction plays a significant role in the later phases of stellar evolution. For a better understanding of the evolution involved, one must understand the corresponding fusion-fission dynamics and reaction characteristics. In the present analysis, we have studied the fusion cross-section along with the S-factor for this reaction using the well-known M3Y and recently developed R3Y nucleon-nucleon (NN) potential along with the relativistic mean-field densities in double folding approach. The density distributions and the microscopic R3Y NN potential are calculated using the NL3 $^{*}$ parameter set. The $ℓ$ - summed Wong model is employed to investigate the fusion cross-section, with $ℓ_{ma x}$ -values from the sharp cut-off model. The calculated results are also then compared with the experimental data. It is found that the R3Y interaction gives a reasonable agreement with the data.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2108.12191 [pdf]
Astron.Nachr.(2021)·4 citations
08
[Submitted on 26 Aug 2021] (cross-list from physics.plasm-ph)
Ion Heat and Parallel Momentum Transport by Stochastic Magnetic Fields and Turbulence
Chang-Chun Chen · Patrick H. Diamond · Steven M. Tobias
The theory of turbulent transport of parallel momentum and ion heat by the interaction of stochastic magnetic fields and turbulence is presented. Attention is focused on determining the kinetic stress and the compressive energy flux. A critical parameter is identified as the ratio of the turbulent scattering rate to the rate of parallel acoustic dispersion. For the parameter large, the kinetic stress takes the form of a viscous stress. For the parameter small, the quasilinear residual stress is recovered. In practice, the viscous stress is the relevant form, and the quasilinear limit is not observable. This is the principal prediction of this paper. A simple physical picture is developed and shown to recover the results of the detailed analysis.
Comments:
16 pages, 5 figures, PPCF invited paper
Subjects:
Plasma Physics (physics.plasm-ph); Nuclear Theory (nucl-th); Fluid Dynamics (physics.flu-dyn)
arXiv:
2108.12066 [pdf]
Plasma Phys.Control.Fusion(2022)·0 citations
09
[Submitted on 27 Aug 2021] (cross-list from hep-ph)
Transverse Momentum and Transverse Momentum Distributions in the MIT Bag Model
A. I. Signal🇳🇿 · F. G. Cao🇳🇿
The typical transverse momentum of a quark in the proton is a basic property of any QCD based model of nucleon structure. However, calculations in phenomenological models typically give rather small values of transverse momenta, which are difficult to reconcile with the larger values observed in high energy experiments such as Drell-Yan reactions and Semi-inclusive deep inelastic scattering. In this letter we calculate the leading twist transverse momentum dependent distribution functions (TMDs) using a generalization of the Adelaide group's relativistic formalism that has previously given good fits to the parton distributions. This enables us to examine the $k_{T}$ dependence of the TMDs in detail, and determine typical widths of these distributions. These are found to be significantly larger than those of previous calculations. We then use TMD factorization in order to evolve these distributions up to experimental scales where we can compare with data on $⟨ k_{T} ⟩$ and $⟨ k_{T}^{2} ⟩$ . Our distributions agree well with this data.
Comments:
17 pages, 4 figures. Final version, accepted for publication in Physics Letters B
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2108.12116 [pdf]
PLB(2022)·13 citations
10
[Submitted on 27 Aug 2021] (cross-list from quant-ph)
QCD Factorization and Quantum Mechanics
C. A. Aidala🇺🇸 · T. C. Rogers🇺🇸
It is unusual to find QCD factorization explained in the language of quantum information science. However, we will discuss how the issue of factorization and its breaking in high-energy QCD processes relates to phenomena like decoherence and entanglement. We will elaborate with several examples and explain them in terms familiar from basic quantum mechanics and quantum information science.
Comments:
12 pages, 9 figures. Invited manuscript for Philosophical Transactions of the Royal Society A
Subjects:
Quantum Physics (quant-ph); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2108.12319 [pdf]
Phil.Trans.A.Math.Phys.Eng.Sci.(2021)·7 citations
11
[Submitted on 27 Aug 2021] (cross-list from hep-ph)
Quantum fluctuation in an inhomogeneous background and its influence on the phase transition in a finite volume system
Xiaogang Li🇨🇳 · Song Shu🇨🇳 · Jia-Rong Li🇨🇳
We have studied the grand potential and phase transitions of an inhomogeneous finite volume spherical quark system. First the finite volume effects are considered by applying the multiple reflection expansion method which is an approximation for the density of states of the momentum in the grand potential of the finite size system. Then, the density of states of momentum is further modified by the thermal fluctuations in the thermal system with the inhomogeneous field background. The modification of the density of states is calculated by the scattering phase shift from the Dirac equation of quarks in the inhomogeneous field background. By the numerical calculation we show how the phase transition is changed by varying the configuration of the inhomogeneous field background and find that the strong first order phase transition could be weakened or even changed to a crossover as a result.
Comments:
13 pages, 12 figures. Some sentences and typos corrected, 2 new plots, matches published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2108.12325 [pdf]
PRC(2022)·6 citations
12
[Submitted on 27 Aug 2021] (cross-list from gr-qc)
Uncertainty limits on neutron star radius measurements with gravitational waves
Katerina Chatziioannou🇺🇸
Upcoming observing campaigns with improved detectors will yield numerous detections of gravitational waves from neutron star binary inspirals. Rare loud signals together with numerous signals of moderate strength promise stringent constraints on the properties of neutron star matter, with a projected radius statistical uncertainty of $50 - 200$ m with $O (2000)$ sources. Given this precision we revisit all analysis assumptions and identify sources of systematic errors, quantify their impact on radius extraction, and discuss their relative importance and ways to mitigate them.
Comments:
5 pages, 3 figures, published version
Subjects:
General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2108.12368 [pdf]
PRD(2022)·74 citations

Affiliations

first authorsco-authorsvia INSPIRE