Nuclear Theory·nucl-th

Monday·October 14, 2019

8 papers—4 primary·4 cross-listed

01
The concept of induced surface and curvature tensions and a unified description of the gas of hard discs and hard spheres
Nazar S. Yakovenko🇺🇦 · Kyrill A. Bugaev🇺🇦 · Larissa V. Bravina🇳🇴 · Eugene E. Zabrodin🇳🇴
Mathematically rigorous derivation of the hadron matter equation of state within the induced surface and curvature tensions approach is worked out. Such an equation of state allows one to go beyond the Van der Waals approximation for the interaction potential of hard spheres. The compressibility of a single- and two-component hadron mixtures are found for two- and three-dimensional cases. The obtained results are compared to the well known one- and two-component equations of state of hard spheres and hard discs. The values of the model parameters which successfully reproduce the above-mentioned equations of state on different intervals of packing fractions are determined from fitting their compressibility factors. It is argued that after some modification the developed approach can be also used to describe the mixtures of gases of convex hard particles of different sizes and shapes.
nucl-thcond-mat.stat-mechEur.Phys.J.ST(2020)·10 citations
02
Nuclear incompressibility from spherical and deformed nuclei
Danilo Gambacurta (ELI-NP, Romania) · Gianluca Colò (University of Milano and INFN, Italy) · Alessandro Pastore (University of York, UK)
We present an analysis based on the deformed Quasi Particle Random Phase Approximation, on top of a deformed Hartree-Fock-Bogoliubov description of the ground state, aimed at studying the isoscalar monopole and quadrupole response in a deformed nucleus. This analysis is motivated by the need of understanding the coupling between the two modes and how it might affect the extraction of the nuclear incompressibility from the monopole distribution. After discussing this motivation, we present the main ingredients of our theoretical framework, and we show some results obtained with the SLy4 and SkM $^{*}$ interactions for the nucleus $^{24}$ Mg.
nucl-thnucl-exJ.Phys.Conf.Ser.(2020)·5 citations
03
Influence of the Pauli principle on two-cluster potential energy
Yu. A. Lashko · V. S. Vasilevsky · G. F. Filippov
We study effects of the Pauli principle on the potential energy of two-cluster systems. The object of the investigation is the lightest nuclei of p-shell with a dominant $α$ -cluster channel. For this aim we construct matrix elements of two-cluster potential energy between cluster oscillator functions with and without full antisymmetrization. Eigenvalues and eigenfunctions of the potential energy matrix are studied in detail. Eigenfunctions of the potential energy operator are presented in oscillator, coordinate and momentum spaces. We demonstrate that the Pauli principle affects more strongly the eigenfunctions than the eigenvalues of the matrix and leads to the formation of resonance and trapped states.
nucl-thSciPost Phys.Proc.(2020)·0 citations
04
Role of resonances in the 8li(p,g)9be capture on reaction rate of the relevant astrophysical synthesis of 9be
S.B. Dubovichenko · N.A. Burkova · A.V. Dzhazairov-Kakhramanov
The total cross sections of the radiative proton capture on 8Li at astrophysical energies were considered in the framework of the modified potential cluster model with forbidden states, with the classification of the orbital cluster states according to Young diagrams. The recalculation of total cross sections for the 9Be({\gamma},p0)8Li photodisintegration was used as experimental data. In whole, it is possible to obtain the available data on cross sections at energies to 7.0 MeV. Astrophysical S-factors and reaction rates at the temperature range of 0.01 to 10 T9 were calculated. It was shown that the resonances in the p8Li scattering channel considerably influence to the reaction rate and, in the first place, the first - at 87 keV. The analytical parametrization was obtained for calculated reaction rate.
nucl-thNPA(2020)·2 citations
05
The viability of the 3+1 neutrino model in the supernova neutrino process
Heamin Ko🇰🇷 · Dukjae Jang🇰🇷 · Motohiko Kusakabe🇨🇳 · Myung-Ki Cheoun🇰🇷
Adopting the 3+1 neutrino mixing parameters by the IceCube and shortbase line experiments, we investigate the sterile-active neutrino oscillation effects on the supernova neutrino process. For the sterile neutrino ( $ν_{s}$ ), we study two different luminosity models. First, we presume that the $ν_{s}$ does not interact with other particles through the standard interactions apart from the oscillation with the active neutrinos. Second, we consider that $ν_{s}$ can be directly produced by $ν_{e}$ scattering with matter. In both cases, we find that the pattern of neutrino oscillations can be changed drastically by the $ν_{s}$ in supernova environments. Especially multiple resonances occur, and consequently affect thermal neutrino-induced reaction rates. As a result, $^{7}$ Li, $^{7}$ Be, $^{11}$ B, $^{11}$ C, $^{92}$ Nb, $^{98}$ Tc and $^{138}$ La yields in the $ν$ -process are changed. Among those nuclei, $^{7}$ Li and $^{11}$ B yields can be constrained by the analysis of observed SiC X grains. Based on the meteoritic data, we conclude that the second model can be allowed while first model is excluded. The viability of the second model depends on the sterile neutrino temperature and the neutrino mass hierarchy.
↳ hep-phastro-ph.SRnucl-thApJ(2020)·7 citations
06
Three particle Lévy HBT from PHENIX
Bálint Kurgyis (for the PHENIX Collaboration)🇭🇺
Bose-Einstein correlations of identical bosons reveal information about the space-time structure of particle emission from the sQGP formed in ultra-relativistic heavy-ion collisions. Previous measurements of two particle correlations have shown that the source can best be described by a symmetric Levy distribution. Here we report on the measurement of three-particle correlations in 0-30 % centrality Au+Au collisions at $s_{_{NN}} = 200$ GeV, and describe them with a Levy type source. This measurement may shed light on hadron creation mechanisms beyond chaotic emission. We measure three particle correlation strength ( $λ_{3}$ ) as a function of pair transverse momentum. This parameter, combined with two-particle correlation strength $λ_{2}$ may reveal the level of chaoticity and coherence in particle production.
↳ nucl-exhep-exnucl-thPhys.Part.Nucl.(2020)·2 citations
07
Correlated Gaussians and low-discrepancy sequences
D. V. Fedorov
Within the Correlated Gaussian Method the parameters of the Gaussian basis functions are often chosen stochastically using pseudo-random sequences. We show that alternative low-discrepancy sequences, also known as quasi-random sequences, provide bases of better quality.
↳ physics.comp-phnucl-thphysics.atom-phFew Body Syst.(2019)·2 citations
08
X-ray assisted nuclear excitation by electron capture in optical laser-generated plasmas
Yuanbin Wu · Christoph H. Keitel · Adriana Pálffy
X-ray assisted nuclear excitation by electron capture (NEEC) into inner-shell atomic holes in a plasma environment generated by strong optical lasers is investigated theoretically. The considered scenario involves the interaction of a strong optical laser with a solid-state nuclear target leading to the generation of a plasma. In addition, intense x-ray radiation from an X-ray Free Electron Laser (XFEL) produces inner-shell holes in the plasma ions, into which NEEC may occur. As case study we consider the $4.85$ -keV transition starting from the 2.4 MeV long-lived $^{93m}$ Mo isomer that can be used to release the energy stored in this metastable nuclear state. We find that the recombination into $2 p_{1/2}$ inner-shell holes is most efficient in driving the nuclear transition. Already at few hundred eV plasma temperature, the generation of inner-shell holes can allow optimal conditions for NEEC, otherwise reached for steady-state plasma conditions in thermodynamical equilibrium only at few keV. The combination of x-ray and optical lasers presents two advantages: first, NEEC rates can be maximized at plasma temperatures where the photoexcitation rate remains low. Second, with mJ-class optical lasers and an XFEL repetition rate of $10$ kHz, the NEEC excitation number can reach $\sim 1$ depleted isomer per second and is competitive with scenarios recently envisaged at petawatt-class lasers.
↳ physics.plasm-phnucl-thPRA(2019)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE