Hisao Matsuzaki

Quasielastic Electron Scattering form Nuclei

Nuclear electroexcitations above the giant resonance energy· region in electron scattering are studied using the quasielastic model. A realistic Woods-Saxon single· particle potential is used in the calculation. The excitation. functions Jor large as welL as small momentum transfers to nuclei are well explained within our model. The position and the width of the quasielastic peak are shown to reflect the binding energies of deep hole states. Our result supports values of the binding energies obtained by the recent (e, e p) experiment. A scalxad ing hypothesis is considered to connect experimentaJ data on different momentum and energy transfers and use of ,such a hypothesis is discussed in. making an estimate of the non-resonant background term in the giant resonance region.

Constraint on √E and Excitation Number

The information· theoretical maximal-entropy procedure for the analysis of collision processes has been successful in various fields: not only for molecular collision processes) but also for nuclear reaction processes. ZH ) The maximalxad entropy approach is useful in describing the evoluxad tion of the system during the collision. A computational evidence for this is given by N esbet:) while a theoretical proof is given by Alhassid and Levine. 6 ) Z ) based on the maximal-entropy approach. Our concern here is the second constraint (on the square root of the internal excitation energy) introduced in their work. The purpose of the present paper is to clarify the underlying physics of this constraint. To begin with, let us briefly review the . maximal-entropy (subject to constraints) theory. The amount of information provided by a populaxad tion is given by the quantity which is called entropy deficiency DS=~P(a)Iog[P(a) /Po(a)] ,

Two-Dimensional Random Walk Process in Heavy Ion Collisions

Two-dimensional random walk model is applied to describe the interrelation between the energy loss and the mass transfer in heavy ion collisions. To take account of the energy loss associated with the mass transfer, we introduce the diagonal steps to the ordinary two-dimenxad sional random walk process. The average of the total kinetic energy loss Eo, as a function of the mass fragmentation, has a minimum at the initial mass fragmentation for the interaction time not very much exceeding the relaxation time. The results obtained from the present model are compared with some experimental data. They are in fairly good agreement with the experimental ones. The optimum values of the fractional energy or the distances of the neighboring sites LYE, are ~ 10 MeV for the 16 0(88 MeV) +27 Al reaction and ~ 24 Me V for the Ar(388 MeV)+ 32 Th reaction. These values of LYE are not contradictory to the assumptions inherent in the present model. We see that the smaller the magnitude of the step is, the less prominent the minima of the Eo as functions of the mass of the reaction products are. In the limit of the infinitesimal steps, i.e., the Fokker-Planck version, the minima disappear. So, in the context of the present model, the finite magnitude of the steps of the walker is suggested, together with the existence of diagonal steps.

Linear Surprisal and Stochastic Process. II: Within the Framework of Fokker-Planck Equation

Pour des processus de diffusion a une dimension, on montre que la surprise lineaire est conservee seulement pour ceux obtenus comme processus limite dun processus naissance, mort et immigration simple

Non-Markovian Langevin Equation Applied to Heavy Ion Collisions

The time evolution of the energy dissipation in heavy ion collisions is expressed by a nonxad Markovian Langevin equation which has two relaxation times. It is suggested that the kinetic energy above the Coulomb barrier dissipates rapidly with the same relaxation time as the fast process of the mass transport.

ON THE BOUND STATE OF THREE-ALPHA SYSTEM

Publisher Summary The calculated values of binding energy are quite different from each other ranging from 13 MeV to 3 MeV due to the different choices of interaction. This chapter describes a separable potential that reproduces the phase shifts caused by the nuclear part of the alpha–alpha interaction. The nuclear part of the alpha–alpha interaction gives a bound state at −l.4 MeV for S-wave. The inclusion of S, D, and G waves is suggested by the L-S coupling shell model of Be. In the neighborhood of the origin, the bound state wave function of the alpha–alpha system behaves as the fourth and higher powers of r. The Yamaguchi type potential yields a closer energy eigenvalue to the ground state of 12C but with the expense of worse fit to the phase shifts of the alpha–alpha scattering. The inclusion of D and G waves does not significantly improve the calculated value of the binding energy. Any alpha–alpha potential, which fits alpha–alpha experimental phase shifts, does not yield the energy of C.