Shuichiro Ebata

Canonical-basis time-dependent Hartree-Fock-Bogoliubov theory and linear-response calculations

We present simple equations for a canonical-basis (Cb) formulation of the time-dependent Hartree-Fock-Bogoliubov (TDHFB) theory. The equations are obtained from the TDHFB theory with an approximation that the pair potential is assumed to be diagonal in the Cb. The Cb formulation significantly reduces the computational cost. We apply the method to linear-response calculations for even-even light nuclei and demonstrate its capability and accuracy by comparing our results with recent calculations of the quasiparticle random-phase approximation with Skyrme functionals. We show systematic studies of E1 strength distributions for Ne and Mg isotopes. The evolution of the low-lying pygmy strength seems to be determined by the interplay of several factors, which include the neutron excess, the separation energy, the neutron-shell effects, the deformation, and the pairing.

Systematic investigation of low-lying dipole modes using the canonical-basis time-dependent Hartree-Fock-Bogoliubov theory

Elementary modes of excitation provide us with fundamental information on quantum many-body sytems. A novel structure in the ground state may lead to a new type of elementary excitations. In studies of radioactive isotopes, the low-energy electric dipole (E1) modes of excitation, Pygmy dipole resonance (PDR), are currently of significant interest. The giant dipole resonance (GDR) at high frequency is a fundamental mode of excitation in finite nuclei. The GDR is universally observed in all nuclei, from light to heavy, from stable to unstable isotopes, and exhausts almost 100 % of the energy-weighted sum rule (EWSR) value. It is also know to reflect bulk properties of nuclei, such as the symmetry energy. In contrast, the PDR is sensitive to structure of an individual nucleus. Since most of the E1 strength is carried by the GDR, the E1 strength of low-energy states is known to be significantly hindered. The presence of substantial E1 stregnth in the PDR implies that the structure of the nucleus is significantly different from our conventional understanding. Thus, it is important to identify the basic property and the origin of the PDR.

Low-lying electric-dipole strengths of Ca, Ni, and Sn isotopes imprinted on total reaction cross sections

Low-lying electric-dipole (

Octupole deformation in the nuclear chart based on the 3D Skyrme Hartree–Fock plus BCS model

E1

Pairing Effects in Nuclear Fusion Reaction

) strength of a neutron-rich nucleus contains information on neutron-skin thickness, deformation, and shell evolution. We discuss the possibility of making use of total reaction cross sections on

Multiple-scattering effects in proton- and alpha-nucleus reactions with Glauber theory

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Systematic investigation of El strength for the isotopes from Z = 28 to 50

Ca,

Neutron-skin thickness determines the surface tension of a compressible nuclear droplet

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Thick-target transmission method for excitation functions of interaction cross sections

Sn, and

Repulsive aspects of pairing correlation in nuclear fusion reaction

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