Nuclear Theory·nucl-th

Wednesday·April 20, 2022

11 papers—5 primary·6 cross-listed

01
[Submitted on 19 Apr 2022]
Averaged transverse momentum correlations of hadrons in relativistic heavy-ion collisions
Yan-ting Feng🇨🇳 · Feng-lan Shao🇨🇳 · Jun Song🇨🇳
We compile experimental data for the averaged transverse momentum ( $⟨ p_{T} ⟩$ ) of proton, $Λ$ , $Ξ^{-}$ , $Ω^{-}$ and $ϕ$ at mid-rapidity in Au+Au collisions at $s_{N N} =$ 200, 39, 27, 19.6, 11.5, 7.7 GeV and in Pb+Pb collisions at $s_{N N} =$ 2.76 TeV, and find that experimental data of these hadrons exhibit systematic correlations. We apply a quark combination model with equal-velocity combination approximation to derive analytic formulas of hadronic $⟨ p_{T} ⟩$ in the case of exponential form of quark $p_{T}$ spectra at hadronization. We use them to successfully explain the systematic correlations exhibited in $⟨ p_{T} ⟩$ data of $p Λ$ , $Λ Ξ^{-}$ , $Ξ^{-} Ω^{-}$ and $Ξ^{-} ϕ$ pairs. We also use them to successfully explain the regularity observed in $⟨ p_{T} ⟩$ of these hadrons as the function of $(d N_{c h} / d y) / (N_{p a r t} /2)$ at mid-rapidity in central heavy-ion collisions at both RHIC and LHC energies. Our results suggest that the constituent quark degrees of freedom and the equal-velocity combination of these constituent quarks at hadronization play important role in understanding the production of baryons and $ϕ$ meson at these RHIC and LHC energies.
Comments:
10 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2204.08641 [pdf]
PRC(2022)·6 citations
02
[Submitted on 19 Apr 2022]
Symplectic Effective Field Theory for Nuclear Structure Studies
D. Kekejian🇺🇸 · J. P. Draayer🇺🇸 · V. I. Mokeev🇺🇸 · C. D. Roberts🇨🇳
A Symplectic Effective Field Theory that unveils the observed emergence of symplectic symmetry in atomic nuclei is advanced. Specifically, starting from a simple extension of the harmonic-oscillator Lagrangian, an effective field theory applied against symplectic basis states is shown to yield a Hamiltonian system with one fitted parameter. The scale of the system can be determined self consistently as the ratio of the average volume of a nucleus assumed to be spherical to its volume as determined by the average number of oscillator quanta, which is stretched by the fact that the plane-wave solution satisfies the equations of motion at every order without the need for perturbative corrections. As an application of the theory, results for 20Ne, 22Ne and 22Mg are presented that yield energy spectra, B(E2) values, and matter radii in good agreement with experimentally measured results.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2204.08642 [pdf]
PRC(2022)·1 citation
03
[Submitted on 19 Apr 2022]
Enhanced proton-boron nuclear fusion cross sections in intense high-frequency laser
Wenjuan Lv · Hao Duan · Jie Liu
We investigate the proton-boron nuclear fusion cross sections under the influence of the intense linearly polarized monochromatic laser fields with high frequency. First, we rewrite the time-dependent Schrödinger equation using Kramers-Henneberger (KH) transformation which allows for shifting all time dependence of the problem into the potential function. Then, for the intense laser fields that satisfy the high frequency limit, the time-averaged scheme in the KH framework should be valid. We can use WKB approximation to evaluate Coulomb barrier penetrability and then calculate proton-boron nuclear fusion cross sections by a phenomenological Gamow form. We show that the corresponding Coulomb barrier penetrability increases significantly due to the depression of the time-averaged potential barrier. As a result, we find that proton-boron nuclear fusion cross sections can be enhanced effectively depending on a dimensionless quantity $n_{d}$ , which equals the ratio of the quiver oscillation amplitude to the geometrical touching radius of the proton and boron nucleus. For $n_{d} = 9$ , we predict that the resonance peak of the fusion cross-section is enhanced by about $26$ times at the incident energy of $ε = 148$ keV. And for another incident energy of $ε = 586$ keV, the resonance peak of fusion cross-section is not only enhanced but also shifted to lower energy of $ε = 392$ keV due to the mechanism of over-barrier fusion.
Comments:
arXiv admin note: text overlap with arXiv:2107.03085
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2204.08667 [pdf]
NPA(2022)·5 citations
04
[Submitted on 19 Apr 2022]
Finite amplitude method on the deformed relativistic Hartree-Bogoliubov theory in continuum: The isoscalar giant monopole resonance in exotic nuclei
Xuwei Sun · Jie Meng
Finite amplitude method based on the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc-FAM) is developed and applied to study isoscalar giant monopole resonance in exotic nuclei. Validation of the numerical implementation is examined for $^{208} Pb$ . The isoscalar giant monopole resonances for even-even calcium isotopes from $^{40} Ca$ to the last bound neutron-rich nucleus $^{80} Ca$ are calculated, and a good agreement with the available experimental centroid energies is obtained for $^{40 - 48} Ca$ . For the exotic calcium isotopes, e.g., $^{68} Ca$ and $^{80} Ca$ , the DRHBc-FAM calculated results are closer to the energy weighted sum rule than the calculations on the harmonic oscillator basis, which highlights the advantages of DRHBc-FAM in describing giant resonances for exotic nuclei. In order to explore the soft monopole mode in the exotic nuclei, the giant monopole resonance for the deformed exotic nucleus $^{200} Nd$ is investigated, where the prolate shape and the oblate shape coexist. A soft monopole mode near 6.0 MeV is found in the prolate case, and another one near 4.5 MeV is found in the oblate case. The transition density of the soft monopole mode shows in phase or out-of-phase vibrations near the surface region, which is generated by quadrupole vibrations.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2204.08677 [pdf]
PRC(2022)·21 citations
05
[Submitted on 19 Apr 2022]
Neutron star radii, deformabilities, and moments of inertia from experimental and ab initio theory constraints on the 208Pb neutron skin thickness
Yeunhwan Lim🇰🇷 · Jeremy W. Holt🇺🇸
Recent experimental and ab initio theory investigations of the 208Pb neutron skin thickness are sufficiently precise to inform the neutron star equation of state. In particular, the strong correlation between the 208Pb neutron skin thickness and the pressure of neutron matter at normal nuclear densities leads to modified predictions for the radii, tidal deformabilities, and moments of inertia of typical 1.4 solar-mass neutron stars. In the present work, we study the relative impact of these recent analyses of the 208Pb neutron skin thickness on bulk properties of neutron stars within a Bayesian statistical analysis. Two models for the equation of state prior are employed in order to study the role of the highly uncertain high-density equation of state. From our combined Bayesian analysis of nuclear theory, nuclear experiment, and observational constraints on the dense matter equation of state, we find at the 90% credibility level $R_{1.4} = 12.3 6_{- 0.73}^{+ 0.38}$ km for the radius of a 1.4 solar-mass neutron star, $R_{2.0} = 11.9 6_{- 0.71}^{+ 0.94}$ km for the radius of a 2.0 solar-mass neutron star, $Λ_{1.4} = 44 0_{- 144}^{+ 103}$ for the tidal deformability of a 1.4 solar-mass neutron star, and $I_{1.338} = 1.42 5_{- 0.146}^{+ 0.074} \times 1 0^{45} g cm^{2}$ for the moment of inertia of PSR J0737-3039A whose mass is 1.338 solar masses.
Comments:
13 pages, 6 figures. Submitted to Galaxies special issue "Neutron Stars and Hadrons in the Era of Gravitational Wave Astrophysics"
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2204.09000 [pdf]
Galaxies(2022)·27 citations

Affiliations

first authorsco-authorsvia INSPIRE

Averaged transverse momentum correlations of hadrons in relativistic heavy-ion collisions

Symplectic Effective Field Theory for Nuclear Structure Studies

Enhanced proton-boron nuclear fusion cross sections in intense high-frequency laser

Finite amplitude method on the deformed relativistic Hartree-Bogoliubov theory in continuum: The isoscalar giant monopole resonance in exotic nuclei

Neutron star radii, deformabilities, and moments of inertia from experimental and ab initio theory constraints on the 208Pb neutron skin thickness

Affiliations