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[en] I use a simple model to parameterize mirror energy differences for several nuclei with N=8 or 10 and their mirrors with Z=8 or 10. I then use the results of the fit to predict the energy of the ground state of the unbound nucleus 15Ne: E2p=2.68(24) MeV.
[en] On the basis of present calculations, the breaking of a particular pair in the lowest lying 3qp state have been pointed out. The generalization of the rule to configuration dependent pairing energy calculations and hence its applications for configuration assignments to three-quasiparticle bands are also discussed
[en] Quadrupole-type collective excitations of even-even nuclei are analyzed. In this analysis, transverse γ vibrations of the nuclear surface are taken into account effectively, while longitudinal beta vibrations remain free. A potential energy of the exponential form is used for free surface longitudinal beta vibrations. The behavior of the energy levels of excited states in the ground-state, β, and γ bands of heavy nuclei is studied, and the predictive potential of the model used is demonstrated for transfermium nuclei.
[en] The increasing need for nuclear data far from the valley of stability requires information on nuclei which cannot be accessed experimentally or for which almost no experimental data is known. Consequently, the use of microscopic approaches to predict properties of such poorly known nuclei is necessary as a first step to improve the quality of nuclear data evaluations. Within this context, large scale mean field calculations from proton to neutron drip-lines have been performed using the Hartree-Fock-Bogoliubov method based on the Gogny nucleon-nucleon effective interaction. This extensive study has shown the ability of the method to reproduce bulk nuclear structure data available experimentally. This includes nuclear masses, radii, matter densities, deformations, moment of inertia as well as collective mode (low energy and giant resonances). In particular, the first mass table based on a Gogny-Hartree-Fock-Bogolyubov calculation including an explicit and coherent account of all the quadrupole correlation energies is presented. The rms deviation with respect to essentially all the available mass data is 798 keV. Nearly 8000 nuclei have been studied under the axial symmetry hypothesis and going beyond the mean-field approach. The corresponding properties are made available to the nuclear scientific community on an Internet web site for every individual nucleus. The content and original feature of this nuclear data library is also presented. (authors)
[en] Empirical correlations in isotopic differentials of charge radii have been combined with the differentials for data on the energy of the first excited 2+ state, on R4/2=E(4+1)/E(2+1), on the transition rate from the 2+1 to the ground state and the two neutron separation energies. These differential results exhibit remarkable consistency with each other although, individually, structure and/or mass observables reveal different patterns. In the past, there are number of valuable studies of isotope shifts comparable to different observables but not the direct correlations as will be presented here. We show that a single general pattern occurs for five different observables for each mass region. This helps one to follow the structural changes more easily by looking at one type of pattern. This study may be a guide for both experimental studies, future measurements in charge radii, masses, spectroscopic observables, and theoretical studies.
[en] The excitation energies of states belonging to the ground state bands of heavy even–even nuclei are analysed using recurrence relations. Excellent agreement with experimental data at the 10 keV level is obtained by taking into account strong correlations which emerge in the analysis. This implies that the excitation energies can be written as a polynomial of maximum degree 4 in the angular momentum. (paper)
[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] There exists a variety of nuclear structure phenomena within the chain of Zr isotopes in the low-excitation regime. While the ground state of 94Zr is spherical in nature, the occurrence of low-lying collective structure has also been observed. The excitation of protons across the Z = 40 sub-shell closure appears to playa dominant role for this collective structure in 94Zr. With the goal of looking for possible competition between proton and neutron excitations in 94Zr, an experiment was carried out at the TRIUMF-ISAC radioactive beam facility. The low-lying states of 94Zr were populated from the β- decay of 94Y. The 8π spectrometer was composed of 20 Compton-suppressed HPGe detectors; details of the experimental setup can be found in earlier literature. Combining the singles and coincidence data, a comprehensive level scheme of 94Zr has been constructed up to Ex ∼ 4.8 MeV, which is very close to the Qβ- value 4.918 MeV. With the revised level lifetimes and the newly found decay branches from the present investigation, the levels could be categorized in terms of proton and neutron excitations. Detailed results obtained from the analysis of the acquired data will be presented
[en] The work distribution of an expanding extreme relativistic gas is shown to be a gamma distribution with a different shape parameter as compared with its non-relativistic counterpart. This implies that the shape of the transverse energy distribution in relativistic heavy ion collisions depends on the particle contents during the evolution of the hot and dense matter. Therefore, transverse energy fluctuations provide additional insights into the Quark–Gluon Plasma produced in these collisions.
[en] Based on our previous works about the configuration-constrained potential-energy-surface model investigating multi-quasiparticle high-K states, we have further developed the cranking configuration-constrained total Routhian surface method to calculate the collective rotations of the multi-quasiparticle high-K states. The non-axial deformed Woods-Saxon potential has been adopted to obtain single-particle levels. The Woods-Saxon potential gives excellent single-particle level spacing, which is very important for the excitation energy calculations of high-K states. In order to improve pairing calculations, a particle-number-conserving pairing method has been incorporated into the TRS calculation. The calculated moments of inertia can well reproduce experimental values. The structures of the high-K states can be analyzed by the calculations