Entrance channel effects on the role of isospin-dependent momentum interaction in isospin fractionation in heavy ion collisions

An isospin degree of freedom is inserted into the momentum dependent interaction in the quantum molecular dynamics model to obtain an isospin dependent momentum interaction given in a form practically usable in isospin dependent quantum molecular dynamics model. We investigate the entrance channel effects for the role of isospin momentum dependent interaction on the isospin fractionation ratio and its dynamical mechanism in the intermediate energy heavy ion collisions. It is found that the isospin dependent momentum interaction induces a significant reduction of isospin fractionation ratio under all entrance channel conditions. However the strong dependence of isospin fractionation ratio on the symmetry potential is preserved after considering the isospin degree of freedom in the momentum dependent interaction.

Isospin-dependent pairing interaction from nuclear matter calculations

The isospin dependence of the effective pairing interaction is discussed on the basis of the Bardeen, Cooper, and Schrieffer theory of superfluid asymmetric nuclear matter. It is shown that the energy gap, calculated within the mean field approximation in the range from symmetric nuclear matter to pure neutron matter, is not linearly dependent on the symmetry parameter owing to the nonlinear structure of the gap equation. Moreover, the construction of a zero-range effective pairing interaction compatible with the neutron and proton gaps in homogeneous matter is investigated, along with some recent proposals of isospin dependence tested on the nuclear data table.

Isospin effects of the Skyrme potential and the momentum dependent interaction at intermediate energy heavy ion collisions

We improve the isospin dependent quantum molecular dynamical model by including isospin effects in the Skyrme potential and the momentum dependent interaction to obtain an isospin dependent Skyrme potential and an isospin dependent momentum interaction. We investigate the isospin effects of Skyrme potential and momentum dependent interaction on the isospin fractionation ratio and the dynamical mechanism in intermediate energy heavy ion collisions. It is found that the isospin dependent Skyrme potential and the isospin dependent momentum interaction produce some important isospin effects in the isospin fractionation ratio

Isospin- and momentum-dependent interaction in isospin-dependent quantum molecular dynamics

An isospin-dependent quantum molecular dynamical model (IQMD) is developed, with the isospin degree of freedom in the momentum-dependent interaction(MDI) included in IQMD, to obtain an isospin- and momentum-dependent interaction (IMDI) in IQMD. We investigate the effect of IMDI on the isospin fractionation ratio and its dynamical mechanism in the intermediate energy heavy ion collisions. It is found that the IMDI induces the significant reductions in the isospin fractionation ratio for all of beam energies, impact parameters, neutron-proton ratios and mass number of colliding systems. However, the strong dependence of isospin fractionation ratio on the symmetrical potential is preserved, with the isospin degree of freedom included in the MDI, i.e. the isospin fractionation ratio is still a good probe for extracting the information about the equation of state of isospin asymmetrical nuclear matter.

Probing balance energy using momentum- and isospin-dependent potential

Using the momentum- and isospin-dependent Boltmann-Uehling-Uhlenbeck (BUU) model, we investigate the transverse flow and balance energy in two isotopic colliding systems Ca-48+Fe-58 and Cr-48+Ni-58 by adopting different symmetry potentials. By comparing the results between the two colliding systems, we find that the difference between the balance energies of two isotopic systems can be considered as a sensitive probe to the density dependence of symmetry energy.

Energy-dependent point interaction: Self-adjointness

Recently, we constructed an energy-dependent point interaction (EDPI) in its most general form in one-dimensional quantum mechanics. In this paper, we show that stationary solutions of the Schrodinger equation with the EDPI form a complete set. Then any nonstationary solution of the time-dependent Schrodinger equation can be expressed as a linear combination of stationary solutions. This, however, does not necessarily mean that the EDPI is self-adjoint and the time-development of the nonstationary state is unitary. The EDPI is self-adjoint provided that the stationary solutions are all orthogonal to one another. We illustrate situations in which this orthogonality condition is not satisfied.

Three-Dimensional Low-Momentum Interaction in Two-Body Bound State Calculations

The deuteron binding energy and wave function are calculated by using the recently developed three-dimensional form of low-momentum nucleon-nucleon (NN) interaction. The homogeneous Lippmann-Schwinger equation is solved in momentum space by using the low-momentum two-body interaction, which is constructed from Malfliet-Tjon potential. The results for both, deuteron binding energy and wave function, obtained with low-momentum interaction, are compared with the corresponding results obtained with bare potential. © 2012 Springer-Verlag.