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[en] Recent structure studies on 64Zn with two protons outside the major shell (Z = 28) has become essential in describing their energy spectrum that are obtained experimentally. Statistical theory of hot rotating nuclei (STHRN) method has been implied to investigate the effect of pair breaking phenomena for temperature (T > 1 MeV) and spin (M = 0 - 15ħ). The energy eigenvalues were obtained by diagonalizing Cranked Nilsson Hamiltonian for deformation parameter ε = 0.0 to 0.6 and shape parameter γ= -1800 to -1200. Excitation energy calculated using STHRN method gives very good comparison with the experimentally found excited levels. Back bending phenomenon and Moment of inertia plot serves as an evidence for the occurrence of pair breaking of nucleons around M = 6ħ and a shape transition from collective prolate to non-collective oblate is also observed. It is found that the value of neutron separation energy decreases (Sn) and proton separation energy (Sp) increases around the angular momentum M = 6ħ. The decrease in the value of Sn indicates that the neutrons are loosely bound to the nucleus. Thus it is concluded that the neutron pair is broken and it eventually lead to shape transition. (author)
[en] A detailed and systematic study has been performed using state dependent Relativistic Mean-Field plus BCS (RMF+BCS) approach to investigate shape evolution for even-even isotopes of Ne, Mg, Si and S. We perform quadrupole constraint calculation using NL3* parameter and look into the variation of binding energy with respect to deformation and find the shape and deformation corresponding to energy minima. We find various isotopes showing shape coexistence and shape transition while moving from proton drip-line to neutron drip-line. These results are compared with Macroscopic-microscopic approach (Mac-Mic) with Nilson Strutinsky (NS) prescription and some other works and are found consistent for these sd-shell nuclei. (author)
[en] In Newtonian fluid dynamics simulations in which composition has been tracked by a nuclear reaction network, energy generation due to composition changes has generally been handled as a separate source term in the energy equation. Here, a relativistic equation in conservative form for total fluid energy, obtained from the spacetime divergence of the stress-energy tensor, in principle encompasses such energy generation; but it is not explicitly manifest. An alternative relativistic energy equation in conservative form—in which the nuclear energy generation appears explicitly, and that reduces directly to the Newtonian internal+kinetic energy in the appropriate limit—emerges naturally and self-consistently from the difference of the equation for total fluid energy and the equation for baryon number conservation multiplied by the average baryon mass m, when m is expressed in terms of contributions from the nuclear species in the fluid, and allowed to be mutable.
[en] The ground-state properties of nuclei with 8 Z 120 from the proton drip line to the neutron drip line have been investigated using the relativistic continuum Hartree-Bogoliubov (RCHB) theory with the relativistic density functional PC-PK1. With the effects of the continuum included, there are totally 9035 nuclei predicted to be bound, which largely extends the existing nuclear landscapes predicted with other methods. The calculated binding energies, separation energies, neutron and proton Fermi surfaces, root-mean-square (rms) radii of neutron, proton, matter, and charge distributions, ground-state spins and parities are tabulated. The extension of the nuclear landscape obtained with RCHB is discussed in detail, in particular for the neutron-rich side, in comparison with the relativistic mean field calculations without pairing correlations and also other predicted landscapes. Here, it is found that the coupling between the bound states and the continuum due to the pairing correlations plays an essential role in extending the nuclear landscape. The systematics of the separation energies, radii, densities, potentials and pairing energies of the RCHB calculations are also discussed. In addition, the α-decay energies and proton emitters based on the RCHB calculations are investigated.
[en] The future Long-Baseline Neutrino Experiment, as one of the third generation neutrino experiment is focusing on the determination of neutrino mass hierarchy, octant degeneracy and CP violation. To realize this ambitious program it is necessary to pin down the systematic uncertainties in the proposed experiments. The relevant sources of uncertainty (i.e. energy calibration, flux normalization, nuclear effects and so on) must be examined carefully, particularly those related to neutrino energy reconstruction since in neutrino oscillation experiments, the oscillation parameters are extracted from the energy distribution of collected events. Hence a precise reconstruction of neutrino energy is a prerequisite for a precise predictions of oscillation physics
[en] The level density can be written as a sum of average and oscillating part, g(E) = g-bar(E) + δg(E). As a result of the connection between oscillating part of level density and the classical periodic orbits, shell effects appear in the level density. Utilizing the level density for spherical harmonic oscillator along with spin-orbit interactions, the present work highlights the description of radioactivity in spherical nuclei such as 146Sm, 148Gd. Qα values for these are calculated by introducing shell and pairing corrections to the liquid drop binding energy
[en] The purpose of present work to investigate theoretically the two neutron separation energy (S2n) which reflects the magicity of Shell Structure in the isotopic chains of Germanium, Selenium, Strontium and Krypton. Our results are complimented by the close agreement with the recent available experimental data
[en] Synthesis of superheavy elements beyond oganesson is facing new challenges as new target–projectile combinations are necessary. Guidance from models is thus expected for future experiments. However, hindered fusion models are not well established and predictions in the fission barriers span few MeVs. Consequently, predictions are not reliable. Strategies to constrain both fusion hindrance and fission barriers are necessary to improve the predictive power of the models. But, there is no hope to get an accuracy better than one order of magnitude in fusion–evaporation reactions leading to superheavy elements synthesis.
[en] Relativistic mean-field (RMF) models with density dependent (DD) couplings have been used successfully to describe finite nuclei and nuclear matter. They usually assume a dependence of the nucleon-meson couplings on the so-called vector density that is derived from the baryon current. A dependence on other densities, in particular the scalar density, was not really explored although suggested in early introductions of the DD-RMF approach. In this contribution, properties of nuclei, the corresponding equations of state (EoS) and symmetry energies of different DD-RMF models are compared using DD couplings of various functional form and dependence on vector and scalar densities. They are obtained by fitting the same set of nuclear observables. The choice of the dependence changes the EoS and the characteristic nuclear matter parameters. Problems of some of the models are identified.