Kinetic energy in the collective quadrupole Hamiltonian from the experimental data

Dependence of the kinetic energy term of the collective nuclear Hamiltonian on collective momentum is considered. It is shown that the fourth order in collective momentum term of the collective quadrupole Hamiltonian generates a sizable effect on the excitation energies and the matrix elements of the quadrupole moment operator. It is demonstrated that the results of calculation are sensitive to the values of some matrix elements of the quadrupole moment. It stresses the importance for a concrete nucleus to have the experimental data for the reduced matrix elements of the quadrupole moment operator taken between all low lying states with the angular momenta not exceeding 4

Friction Coefficient for Deep-Inelastic Heavy-Ion Collisions

Based on the microscopic model, the friction coefficient for the relative motion of nuclei in deep-inelastic heavy-ion collisions is calculated. The radial dependence of the friction coefficient is studied and the results are compared with those found by other methods. Based on this result, it was demonstrated that the kinetic energy dissipation in deep-inelastic heavy-ion collisions is a gradual process which takes up a significant part of a reaction time. An advantage of the suggested method is that it allows one to consider the relative motion of nuclei and the intrinsic motion self-consistently.Comment: 15 pages, RevTex, 7 Postscript figures, submitted to Phys. Rev.

On neutron number dependence of B(E1;0+ --> 1-) reduced transition probability

A neutron number dependence of the E1 0+ --> 1- reduced transition probability in spherical even--even nuclei is analysed within the Q--phonon approach in the fermionic space to describe the structure of collective states. Microscopic calculations of the E1 0+ --> 1- transition matrix elements are carried out for the Xe isotopes based on the RPA for the ground state wave function. A satisfactory description of the experimental data is obtained.Comment: 8 pages, 4 figure

Simple relations among E2 matrix elements of low-lying collective states

A method is developed to derive simple relations among the reduced matrix elements of the quadrupole operator between low-lying collective states. As an example, the fourth order scalars of Q are considered. The accuracy and validity of the proposed relations is checked for the ECQF Hamiltonian of the IBM-1 in the whole parameter space of the Casten triangle. Furthermore these relations are successfully tested for low-lying collective states in nuclei for which all relevant data is available.Comment: 12 pages, 1 figure, RevTeX preprint-styl