Experimentally observed superdeformed(SD) rotational bands in ^(36)Ar and ^(40)Ar are studied by the cranked shell model(CSM) with the pairing correlations treated by a particle-number-conserving(PNC) method.This is the first time that PNC-CSM calculations have been performed on the light nuclear mass region around A=40.The experimental kinematic moments of inertia J^((1))versus rotational frequency are reproduced well. The backbending of the SD band at frequency around ω =1.5 Me V in ^(36)Ar is attributed to the sharp rise of the simultaneous alignments of the neutron and proton 1 d_(5/2)[202]5/2 pairs and 1 f_(7/2)[321]3/2 pairs, which is a consequence of the band crossing between the 1 d_(5/2)[202]5/2 and 1 f_(7/2)[321]3/2 configuration states. The gentle upbending at low frequency of the SD band in ^(40)Ar is mainly affected by the alignments of the neutron 1 f_(7/2)[321]3/2 pairs and proton 1 d_(5/2)[202]5/2 pairs.The PNC-CSM calculations show that besides the diagonal parts, the off-diagonal parts of the alignments play an important role in the rotational behavior of the SD bands.
The recently observed two high-spin rotational bands in the proton emitter ^(113)Cs are investigated using the cranked shell model with pairing correlations treated by a particle-number conserving method, in which the Pauli blocking effects are taken into account exactly. By using the configuration assignments of band 1 [π3/2^+[422](g_(7/2)), α =-1/2] and band 2 [π1/2^+[420](d_(5/2)), α=1/2], the experimental moments of inertia and quasiparticle alignments can be reproduced much better by the present calculations than those using the configuration assginment of π1/2^-[550](h_(11/2)), which in turn may support these configuration assignments. Furthermore, by analyzing the occupation probability nμ of each cranked Nilsson level near the Fermi surface and the contribution of each orbital to the angular momentum alignments, the backbending mechanism of these two bands is also investigated.
Ground state properties for Mg isotopes,including binding energies,one- and two-neutron separation energies,pairing energies,nuclear matter radii and quadrupole deformation parameters,are obtained from the selfconsistent relativistic mean field(RMF) model with the pairing correlations treated by a shell-mode-like approach(SLAP),in which the particle-number is conserved and the blocking effects are treated exactly.The experimental data,including the binding energies and the one- and two-neutron separation energies,which are sensitive to the treatment of pairing correlations and block effects,are well reproduced by the RMF+SLAP calculations.
The nuclear dynamical deformation,the fusion probability and the evaporation residue(ER) cross sections for the synthesis of superheavy nuclei are studied with the di-nuclear system model and the related dynamical potential energy surface.The intrinsic energy and the maximum dynamical deformations for48Ca+248Cm are calculated.The effect of dynamical deformation on the potential energy surface and fusion is investigated.It is found that the dynamical deformation influences the potential energy surface and fusion probability significantly.The dependence of the fusion probability on the angular momentum is investigated.The ER cross sections for some superheavy nuclei in48Ca induced reactions are calculated and it is found that the theoretical results are in good agreement with the experimental results.
