Observation of the Superheavy Nuclide ^(271)Ds

With the recent commissioning of a gas-filled recoil separator at Institute of Modern Physics (IMP) in Lanzhou,the decay properties of 271Ds (Z =110) were studied via the 20sPb(64Ni,n) reaction at a beam energy of 313.3 MeV.Based on the separator coupled with a position sensitive silicon strip detector,we carried out the energy-position-time correlation measurements for the implanted nucleus and its subsequent decay α's.One α-decay chain for 271Ds was established.The α energy and decay time of the 27iDs nucleus were measured to be 10.644 MeV and 96.8ms,which are consistent with the values reported in the literature.

Exploration of Unbound States by Analytical Continuation in the Coupling Constant Method Within Relativistic Mean Field Theory

For the first time,the analytical continuation in the coupling constant method has been combined with the relativistic mean field theory to study the unbound states in spherical nuclei.The 1d_(3/2) neutron state in ^(16)O and the 2d_(5/2) and 1g_(9/2) neutron states in ^(48)Ca are taken as examples.The calculated energies and widths are compared with available data.

Odd Systems in Deformed Relativistic Hartree Bogoliubov Theory in Continuum

In order to describe the exotic nuclear structure in unstable odd-A or odd-odd nuclei,the deformed relativistic Hartree Bogoliubov theory in continuum is extended to incorporate the blocking effect due to the odd nucleon.For a microscopic and self-consistent description of pairing correlations,continuum,deformation,blocking effects,and the extended spatial density distribution in exotic nuclei,the deformed relativistic Hartree Bogoliubov equations are solved in a Woods Saxon basis in which the radial wave functions have a proper asymptotic behavior at large r.The formalism and numerical details are provided.The code is checked by comparing the results with those of spherical relativistic continuum Hartree Bogoliubov theory in the nucleus 19O.The prolate deformed nucleus 15 C is studied by examining the neutron levels and density distributions.

Deformed Relativistic Hartree Theory in Coordinate Space and in Harmonic Oscillator Basis

The deformed relativistic Hartree theory(DRH)is solved both in coordinate space(DRH-c)and in harmonic oscillator basis(DRH-o).Results obtained from these two methods are compared in details.The DRH-c and DRH-o calculations give similar total binding energies,deformation,level structures and radii for nitrogen iso topes,while their descriptions on the density distributions for drip-line nuclei are very different.The large spatiai istributions of nucleon densities,which is crucial to understand a weakly bound system,can only be obtained by DRH-c calculations.This implies that the DRH theory should be solved in coordinate space in order to describe uclei close to the drip line.