Recent experimental results have shown that the optical potential is much more repulsive at energies above 400 MeV/nucleon than believed at the beginning of the eighties. Taking these new data into account we present a new parametrization of the optical potential, of the underlying bare nucleon-nucleon interaction, as well as of its expectation value for Gaussian wave functions as used in quantum molecular dynamics calculation. For the case Au+Au b=3 fm we compare the result for several observables with that obtained employing the old parametrization.

We propose a microscopic theory for interacting mesons and ideal quarks in the relativistic quark model using the time-dependent mean-field theory technique. For simplicity we examined the Nambu–Jona-Lasinio model. The dynamical chiral-symmetry breaking leads to a zero-frequency mode (pion) due to the restoration of chiral symmetry. The ideal quarks are represented as dressed particles independent of mean fields, and do not have the conventional properties of fermions. This is due to the constraints of eliminating the double counting of degrees of freedom between the mean fields and quarks. The small fluctuation around the static solution is then investigated. The pseudoscalar and scalar mesons are represented as the collective modes of the mean fields.

Applying a self-consistent cranked Hartree-Fock-Bogoliubov theory the variation of g factors in ${}_{}{}^{154}{}_{}{}^{}\mathrm{Dy}$ as a function of angular momentum is studied up to high spins, I=40. In the spin range 20–40 our calculated numbers are in a better agreement with the data than the earlier predictions. We find that several single-particle orbitals undergo rotation alignment and proton pairing does not collapse even at I=40.

The fusion of ${}_{}{}^{64}{}_{}{}^{}\mathrm{Ni}$${+}^{100}$Mo and ${}_{}{}^{80}{}_{}{}^{}\mathrm{Se}$${+}^{80}$Se has been studied near and just below the Coulomb barrier. Fusion cross sections and average angular momenta have been calculated in a realistic neck formation fusion model based on barrier penetration, deformations, vibrations, and neck formation. The results agree well with the experimental data.

Response functions and collective modes for asymmetric nuclear matter (N>Z) are studied by means of a relativistic kinetic equation. Nuclear matter is described by means of a field theory of nucleons coupled to neutral, scalar (σ), and vector (ω) mesons and to charged vector mesions (ρ). The contribution of the exchange terms to the nucleon-nucleon interaction is also taken into account. Because of the exchange terms, the kinetic equation presents solutions which correspond to oscillations of the spin density. Finally the effects of an excess of neutrons on the response functions and on the collective modes are investigated. It is found that a collective oscillation present in symmetric nuclear matter disappears even for a small asymmetry (∼5%).

A higher-twist nuclear enhancement of R=${\mathrm{\sigma }}_{\mathit{L}}$/${\mathrm{\sigma }}_{\mathit{T}}$ whose magnitude is within the error bars of recent experiment is shown to lead to a monotonic decrease in the ratio of nuclear versus nucleon cross sections at small Bjorken x for increasing ${\mathit{Q}}^2$. This effect at small X, comparable in magnitude to those reported for nuclear shadowing, is driven mainly by kinematic factors and essentially vanishes for x>0.1. Its unusual ${\mathit{Q}}^2$ dependence rather complicates the unraveling from present data in the shadowing region the corresponding dependence in ${\mathit{Q}}^2$ of the nuclear structure functions, ${\mathit{F}}_2^{\mathit{A}}$(x,${\mathit{Q}}^2$).

We study normalization problems associated with the use of perturbatively correlated ground states in extended random phase approximation schemes in the context of a specific but typical example. The sensitivity of the results to the amount of two-particle–two-hole admixtures to the correlated ground state is also investigated in terms of a modification of the standard perturbative approach.

Sturmian eigenstates specified by stationary scattering boundary conditions are particularly useful in contexts such as forming simple separable two nucleon t matrices, and are determined via solution of generalized eigenvalue equation using real and symmetric matrices. In general, the spectrum of such an equation may contain complex eigenvalues. But to each complex eigenvalue there is a corresponding conjugate partner. In studies using realistic nucleon-nucleon potentials, and in certain positive energy intervals, these complex conjugated pairs indeed appear in the Sturmian spectrum. However, as we demonstrate herein, it is possible to recombine the complex conjugate pairs and corresponding states into a new, sign-definite pair of real quantities with which to effect separable expansions of the (real) nucleon-nucleon reactance matrices.

We investigate the mass spectra of p-wave Λ’s by means of the constituent quark model with the effect of coupling to meson-baryon channels. The quark wave function of the lowest p-wave ${\mathrm{\Lambda }}^{\mathrm{*}}$, i.e., Λ(1405), is found to be dominated by the antisymmetric flavor state which strongly couples to the K¯N and πΣ channels. The significant downward shift of the Λ(1405)’s mass is attributed to its large attractive self-energy due to the K¯N${\mathrm{\Lambda }}^{\mathrm{*}}$ and πΣ${\mathrm{\Lambda }}^{\mathrm{*}}$ coupling and its strong increase due to the presence of the cusp around the K¯N threshold.

The effects of nonlinear scalar field couplings on elastic proton-nucleus scattering observables are investigated using a relativistic impulse approximation. Nonlinear couplings affect in a nontrivial way the effective nucleon mass and the nuclear scalar and vector densities. Modifications on the densities might have observable consequences on scattering observables. Our investigation indicates that the description of the observables for the reactions p${\mathrm{-}}^{16}$O and p${\mathrm{-}}^{40}$Ca at 200 MeV are not greatly modified with the use of nonlinear models in comparison with the description using linear models.

Reacceleration effects in the Coulomb breakup of nuclei are modeled with the two-dimensional time-dependent Schrödinger equation, extending a previous one-dimensional study. The present model better describes the individual contributions of longitudinal and transverse forces to the breakup and reacceleration. Reacceleration effects are found to preserve a strong memory of the pre-breakup phase of the reaction, as was concluded with the one-dimensional model.

The rotational properties of the ν${\mathit{i}}_{13/2}$ band in ${}_{}{}^{179}{}_{}{}^{}\mathrm{Os}$ are discussed and the observed discrepancy between the experimental signature splitting of the quasiparticle Routhians and the signature dependence of the reduced B(M1) transition probabilities is considered as an indication for a triaxial shape of this nucleus. It is consistent with a negative value of the γ-deformation parameter γ≤-10°. The inversion of the crossing frequencies, ħ${\mathrm{\omega }}_{\mathit{A}\mathit{D}}$<ħ${\mathrm{\omega }}_{\mathit{B}\mathit{C}}$, which has been found in the same band, is interpreted within the framework of the cranked shell model as experimental evidence for hexadecapole deformation, corresponding to 0.05<${\mathrm{\epsilon }}_4$<0.07 for the above values of γ.

This is a reply to the ‘‘Comment on ‘Shadow model for sub-barrier fusion applied to light systems.’ ’’ We confirm the results of our paper. The claimed demonstration of the disagreement between the cross section derived from the ‘‘shadow’’ model and the low energy laboratory data is meaningless because it is based on a comparison which is incorrect.

This Comment examines the claim of a lack of evidence for a superdeformed band in ${}_{}{}^{192}{}_{}{}^{}\mathrm{Pb}$. We reaffirm the existence in our data of the superdeformed band in ${}_{}{}^{192}{}_{}{}^{}\mathrm{Pb}$.

In reply to the preceding Comment, we wish to stress that lack of consistency between experiments of similar quality justifies our claim that further searches for a superdeformed band in ${}_{}{}^{192}{}_{}{}^{}\mathrm{Pb}$ with more powerful instruments are called for. We believe that the main results presented in the Comment support this conclusion.

We comment on a recent paper by Uma Maheswari et al. in which it is claimed that quantal calculations of the half-infinite nuclear matter, in contrast to semiclassical approximations, exhibit an unusually strong dependence of the 90%–10% surface thickness of the density profile on the Fermi momentum ${\mathit{k}}_{\mathit{F}}$ at saturation. This conclusion was carried over to the surface incompressibility. On the contrary we find essential agreement between semiclassical and quantal results and very weak dependence on ${\mathit{k}}_{\mathit{F}}$ of the quantities in question.

In reply to the preceding Comment, it is found that the present results regarding the dependence of the surface thickness on the Fermi momentum agree with that of the Comment. However, we differ with the conclusions of the preceding Comment.