Stability of Strutinsky Shell Correction Energy in Relativistic Mean Field Theory

The single-particle spectrum obtained from the relativistic mean field （RMF） theory is used to extract the shell correction energy with the Strutinsky method. Considering the delicate balance between the plateau condition in the Strutinsky smoothing procedure and the convergence for the total binding energy, the proper space sizes used in solving the RMF equations are investigated in detail by taking ^208 Pb as an example. With the proper space sizes, almost the same shell correction energies are obtained by solving the RMF equations either on basis space or in coordinate space.     

Relativistic Mean Field Study on Halo Structures of Mirror Nuclei

Halo structures of some light mirror nuclei are investigated with the relativistic mean field （RMF） theory. The calculations show that the dispersion of the valence proton is larger than that of the valence neutron in its mirror nucleus, the difference between the root-mean-square （rms） radius of the valence nucleon in each pair of mirror nuclei becomes smaller with the increase of the mass number A, and all the ratios of the rms radius of the valence nucleon to that of the matter in each pair of mirror nuclei decrease almost linearly with the increase of the mass number A.     

On the decrease in charge radii of multi-quasi particle isomers

We report changes in mean-square charge radii, δ〈r²〉$\delta 〈r^2〉$, magnetic moments and quadrupole moments for three multi-quasi particle isomers; ^97m2Y, ^176mYb and ^178m1Hf. All the isomers are observed to display a decrease in 〈r²〉$〈r^2〉$ compared to the lower-lying nuclear state on which the isomer is built. The decreases in 〈r²〉$〈r^2〉$ occur despite the isomers showing increases in quadrupole moment. Possible mechanisms for the effect, which is now seen for six multi-quasi particle isomers, are discussed.     

Global systematics of the Wigner energy

Following Zeldes, double-beta decay Q   values are used as a filter for extracting symmetry energy and Wigner energy coefficients across the full range of nuclei, from A=10$A=10$ to A=246$A=246$. The symmetry coefficient extracted is found to vary smoothly with A and mass formula coefficients can be determined for the corresponding symmetry and surface symmetry terms. However, the extracted Wigner coefficient has large standard errors and fluctuates dramatically with A, even as regards its sign. Shell corrections remove most of the fluctuations and allow the determination of a reliable Wigner coefficient for the mass formula.     

Nuclear charge radii of molybdenum fission fragments

Radioisotopes of molybdenum have been studied using laser spectroscopy techniques at the IGISOL facility, University of Jyväskylä. Differences in nuclear charge radii have been determined for neutron deficient isotopes ^90,91Mo and neutron rich isotopes ^{102–106,108}Mo (and all stable isotopes). A smooth transition in the mean square charge radii is observed as the neutron number increases with no sudden shape change observed in the region around N=60$N=60$. As N   increases, the nuclear deformation appears to go beyond a maximum and a fall off at N=66$N=66$ is observed. The magnetic moments of the odd isotopes ^91,103,105Mo are also determined.     

Measurements of g-Factor of Rotational Band States in 82Sr

The g-factors of the positive parity rotational states up to spin I = 8^＋ for the ground state band in even-even nuclei S2Sr have been measured by a transient-magnetic-field ion implantation perturbed angular distribution method. The experimentally measured 9-factors increase with the increasing spin along the band and show that the g9/2 proton aligns only and the alignment starts from I =6^＋. The measured g-factors also indicate that the nuclei ^82Sr gain their spins by the quasi-proton alignment at higher spin.     

Reflection Asymmetric Relativistic Mean Field Approach and Its Application to the Octupole Deformed Nucleus ^226Ra

A reflection asymmetric relativistic mean field （RAS-RMF） approach is developed by expanding the equations of motion for both the nucleons and the mesons on the eigenfunctions of the two-centre harmonic-oscillator potential. The efficiency and reliability of the RAS-RMF approach are demonstrated in its application to the well-known octupole deformed nucleus 226Ra and the available data, including the binding energy and the deformation parameters, are well reproduced.     

Towards a new Gogny force parameterization: Impact of the neutron matter equation of state

A new parameterization of the effective nucleon–nucleon Gogny interaction is proposed. It reproduces the neutron matter equation of state much better than the commonly used D1S Gogny interaction and furthermore reduces the binding energies' drift for the major part of the isotopic chains. Other important nuclear properties related both to nuclear matter and finite nuclei are studied and shown to be of similar quality as with D1S.     

Relativistic Mean Field Study of the Z=117 Isotopic Chain

The properties of the Z = 117 isotopic chain are studied within the framework of the axially deformed relativistic mean field theory （RMFT） in the blocked BCS approximation. The ground-state properties, such as hinging energies, deformations as well as the possible α decay energies and lifetimes are calculated with the parameter set of NL-Z2 and compared with results from the finite range droplet model. The analysis by RMFT shows that the isotopes in the range of mass number A =291 ~ 300 exhibit higher stability, which suggests that they may be promising nuclei to be hopefully synthesized in the lab among the nuclei Z = 117.     

Extreme Exotic Calcium Lambda Hypernuclei in the Relativistic Continuum Hartree--Bogoliubov Theory

Exotic calcium lambda hypernuclei properties with the neutron number of 20-400 by a step of 20 are discussed by employing the relativistic continuum Hartree-Bogoliubov theory with a zero range pairing interaction. The Bethe-Weizsgcker mass formula of a multi-strange system and the Woods-Saxon-type potential of lambda need to be modified for exotic calcium bypernuclei with unusual number of neutrons and lamSdas. The possible neutron and lambda limits of exotic Ca lambda hypernuclei are also investigated.     

Realistic nuclear Hamiltonian: Ab exitu approach

Fully-microscopic no-core shell model (NCSM) calculations of all stable s and p shell nuclei are used to determine a realistic NN   interaction, JISP16, describing not only the two-nucleon data but the binding energies and spectra of nuclei with A?16$A?16$ as well. The JISP16 interaction, providing rapid convergence of the NCSM calculations, is obtained in an ab exitu approach by phase-equivalent transformations of the JISP6 NN interaction.     

Theoretical Calculation for Half-Lives of Spherical Proton Emitters

Half-lives of the proton radioactivity for spherical proton emitters are investigated theoretically in the Wentzel- Kramers-Brillouin approximation. Microscopic proton-nucleus interaction potentials are obtained by folding the densities of the residual daughter nuclei with renormalized M3Y effective interactions. We also take the spectroscopic factor （Sp） into account in the calculation, which is evaluated in the relativistic mean field approach using the force NL3. The calculated results are found to be in good agreement with the experimental data.     

Two-quasiparticle K-isomers and pairing strengths in the neutron-rich isotopes Er and Er

Isomeric two-quasiparticle states have been identified in the neutron-rich isotopes ¹⁷²Er and ¹⁷⁴Er using multi-nucleon transfer reactions with ¹³⁶Xe beams incident on various targets, and γ  -ray spectroscopy with Gammasphere. A candidate for the Kπ=⁶⁺$K^{\pi }=6^{+}$ two-quasineutron state in ¹⁷²Er is found at 1500 keV. In ¹⁷⁴Er, a nuclide whose level scheme was previously unknown, a long-lived isomer is identified at 1112 keV decaying via an inhibited E1 transition and revealing the yrast sequence of ¹⁷⁴Er. This isomer is proposed to be a Kπ=⁸⁻$K^{\pi }=8^{-}$ two-quasineutron state, defining a sequence in the N=106$N=106$ isotones extending from the well-deformed neutron-rich isotope ¹⁷⁴Er to the neutron-deficient isotope ¹⁸⁸Pb, where the presence of the isomer signifies a prolate minimum in an otherwise spherical well. Configuration-constrained potential-energy surface calculations are used to predict the excitation energies of the 6⁺ and 8⁻ intrinsic states and as a basis for extracting the pairing force strength, Gn$G_n$, in the N=104$N=104$ and N=106$N=106$ isotones.     

Theoretical Study on Negative Parity States of^（191,193,195,197） Au in Particle Triaxial-Rotor Model

By taking the particle triaxial-rotor model with variable moment of inertia, we investigate the energy spectra, the deformation and the single particle configuration of the negative-parity states in nuclei^（191,193,194,197） Au systemically. The calculated energy spectra agree well with experimental data. The obtained results indicate that the negative-parity states in^（191,193,195,197）Au originate from the proton-hole h11/2 configuration coupled to a triaxial oblate Hg core. Meanwhile the main single particle configuration of the bands 1, 2 and 3 are identified to be [5h11/2 1/2） （α=-1/2）, [5h11/2 1/2） （α = 1/2） and 15h9/2 7/2）, respectively.     

Band Structures of the Nucleus 129Cs

High-spin states in ^129Cs are populated via the ^122Sn （^11B, 4n） reaction at beam energies of 55 and 60MeV. Two additional bands are placed in the level scheme and the previously known bands are extended to higher spins. The results are compared to the cranked shell model calculations and to the systematics of the adjacent Cs isotpoes. One of the new bands is interpreted as the 7-vibrational band built on the πh11/2 orbital. The possible configuration for another new band is discussed. Upbend caused by （Vh11/2）^2 alignment is observed both in the favored and unfavored sequences of the πh11/2 configuration. The band based on the πgτ/2 configuration at low spins forks around spin 17//2, and the two different S-bands are attributed to （Vh11/2）^2 and （πh11/2）^2 rotational alignments, respectively.     

Dynamics of argon in confined geometry

The role of geometrical confinement on the dynamics of argon is studied. We have investigated ³⁶Argon adsorbed in nanoporous Gelsil glass by inelastic neutron scattering. By fractional filling the `dimensionality' of the system is tuned from a two-dimensional towards the bulk state. Ab-initio calculations of plane sheets of Ar atoms and of bulk Ar are compared to the experimental results. A shift of various phonon modes to lower energies with decreasing dimensionality is observed in the results of both methods.     

Interaction of regular and chaotic states

Modelling the chaotic states in terms of the Gaussian Orthogonal Ensemble of random matrices (GOE), we investigate the interaction of the GOE with regular bound states. The eigenvalues of the latter may or may not be embedded in the GOE spectrum. We derive a generalized form of the Pastur equation for the average Green’s function. We use that equation to study the average and the variance of the shift of the regular states, their spreading width, and the deformation of the GOE spectrum non-perturbatively. We compare our results with various perturbative approaches.