New calculations for the total reaction cross sections (${\mathrm{\sigma }}_{\mathit{R}}$) are carried out within the framework of nuclear transport theory combined with the optical limit of the Glauber theory. The average nucleon-nucleon collision number is obtained based on the nuclear transport theory. The probability of nucleon-nucleon collision, which is assumed to be a Possion distribution, is calculated, and then ${\mathrm{\sigma }}_{\mathit{R}}$ is calculated by using the optical limit of the Glauber theory. The calculated ${\mathrm{\sigma }}_{\mathit{R}}$ are in agreement with the experimental data for reactions induced by both the stable and the exotic nuclei. In addition, the effects of some ingredients on ${\mathrm{\sigma }}_{\mathit{R}}$ can be easily analyzed with the present method. Among them the effects are mainly from Pauli blocking, the nuclear equation of state, the in-medium nucleon-nucleon cross section ${\mathrm{\sigma }}_{\mathit{N}\mathit{N}}$, the effective nucleon density distribution, and the dynamics of nucleus-nucleus collisions. From the calculated energy dependence of ${\mathrm{\sigma }}_{\mathit{R}}$, it is found that the total reaction cross sections are sensitive to the nuclear equation of state when the bombarding energy is below 100 MeV/nucleon and also sensitive to the in-medium nucleon-nucleon cross section in the full researched energy range. Provided that the same nuclear equation of state is applicable to the reactions induced by both the stable and the exotic nuclei in the lower energy range, we seem to have that the in-medium nucleon-nucleon cross section in the exotic nuclei may be larger than in the stable nuclei.

A previously developed nucleon-exchange transport model for preequilibrium neutron and hard photon emission is extended to include proton emission. Several refinements including diffuse ground-state nucleonic momentum distributions and quantal rather than classical bremsstrahlung production are added. The incorporation of a diffuse momentum distribution improves the reproduction of experimental spectra and multiplicities, particularly at low bombarding energies. Quantal bremsstrahlung enhances the production of high-energy photons. The effect of deceleration of the colliding nuclei during the propagation of the jetting particles through the receptor nucleus is explored. The effect of preequilibrium emission on the evaporation residue and its dependence on entrance channel mass asymmetry is studied. The number of preequilibrium particles emitted is inconsistent with some previous analyses of evaporation residue spectra.

The results of the multiplicity distributions of shower, grey, black, and heavily ionizing charged particles from ${}_{}{}^{16}{}_{}{}^{}\mathrm{induced}$ reactions at 200A GeV are presented. The results are compared with the predictions of the Lund Monte Carlo code fritiof, the multichain model by Ranft, and the Monte Carlo code venus.

The photon structure function of the hydrogen molecule is calculated using the known approximate nonrelativistic wave function and the photon-emission vertex of the canonical light-cone Hamiltonian of quantum electrodynamics. The obtained photon structure function is compared to the photon structure function of the hydrogen atom. Typical European Muon Collaboration (EMC)-like effects such as shadowing for small ${\mathit{x}}_{\mathit{B}\mathit{j}}$ and antishadowing for larger ${\mathit{x}}_{\mathit{B}\mathit{j}}$ are found. Shadowing saturates for smallest ${\mathit{x}}_{\mathit{B}\mathit{j}}$ and depends only weakly on resolution ${\mathrm{\Lambda }}^2$. For larger ${\mathit{x}}_{\mathit{B}\mathit{j}}$ the EMC ratio of the structure functions oscillates. We find that the period is inversely proportional to the proton-proton distance in the hydrogen molecule. Also the saturation of shadowing for low ${\mathit{x}}_{\mathit{B}\mathit{j}}$ is understood analytically. Qualitatively the calculated effects in photon structure function of the ${\mathrm{H}}_2$ molecule are similar to those observed in the quark structure function measured in deep inelastic scattering of leptons on nuclei.

Single-particle spectra of Λ and Σ hypernuclei are calculated within a relativistic mean-field theory. The hyperon couplings used are compatible with the Λ binding in saturated nuclear matter, neutron-star masses, and experimental data on Λ levels in hypernuclei. The spin-orbit potentials for the hyperons and the influence of the ρ-meson field (isospin dependent interaction) are discussed.

Relativistic covariance requires that in the constituent quark model for mesons the positive energy state as well as the negative energy states are included. Using relativistic quasipotential equations the contribution of the negative energy states is studied for the light and charmonium mesons. It is found that these states change the meson mass spectrum significanlty but leave its global structure untouched.

The boundary of a quark-gluon plasma affects the momentum distribution of quarks and consequently the magnitudes of signals for the search of the quark-gluon plasma.

The CALTECH γ-transition experiment testing time-reversal symmetry via the E2/M1 multipole mixing ratio of the 122-keV γ line in ${}_{}{}^{57}{}_{}{}^{}\mathrm{Fe}$ has already been performed in 1977. Extending an earlier analysis in terms of an effective one-body potential, this experiment is now analyzed in terms of effective one-boson-exchange T-odd P-even nucleon-nucleon potentials. Within the model space considered for the ${}_{}{}^{57}{}_{}{}^{}\mathrm{Fe}$ nucleus no contribution from isovector ρ-type exchange is possible. The bound on the coupling strength ${\mathrm{\phi }}_{\mathit{A}}$ from effective short-range axial-vector-type exchange induced by the experimental bound on sinη leads to ${\mathrm{\phi }}_{\mathit{A}}$≤${10}^{\mathrm{-}2}$.

A critical evaluation of results from the ${}_{}{}^{177}{}_{}{}^{}\mathrm{Hf}$(d,p) reaction, taken together with gamma-ray data following neutron capture, firmly establishes that the 1862.2 keV $3^{+}$, 1953.1 keV $4^{+}$, and 2068.0 keV $5^{+}$ levels in ${}_{}{}^{178}{}_{}{}^{}\mathrm{Hf}$ unambiguously constitute a ${\mathit{K}}^{\mathrm{\pi }}$=$3^{+}$ band, closely interrelated with the well known ${\mathit{K}}^{\mathrm{\pi }}$=$4^{+}$ band based at 1513.8 keV. These two bands form a doublet with the {7/$2^{\mathrm{-}}$[514]∓1/$2^{\mathrm{-}}$[510]} two-neutron configuration. This assignment necessitates a revision of an earlier interpretation, adopted by Nuclear Data Sheets, placing these levels as rotational members of a ${\mathit{K}}^{\mathrm{\pi }}$=$2^{+}$ band based at 1808.3 keV. Detailed arguments for the revised assignment are presented.

The excitation energies in ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$ of the first two ${\mathit{J}}^{\mathrm{\pi }}$=$1^{\mathrm{-}}$ states above the ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$+α threshold are found to be 7615.9±0.7 keV and 8037.8±0.7 keV. Although these energies agree within errors with the previously adopted values, they are lower by 3 keV and 1 keV, respectively. We also found ${\mathit{E}}_{\mathit{x}}$($2_3^{+}$), the excitation energy of the third $2^{+}$ state, to be 5254.8±0.9 keV in disagreement with the previously adopted value of 5260.4±1.2 keV.

We compute the branching ratio for Δ→${\mathit{Ne}}^{+}$${\mathit{e}}^{\mathrm{-}}$ and Δ→N${\mathrm{\mu }}^{+}$${\mathrm{\mu }}^{\mathrm{-}}$ in chiral perturbation theory and find that both decays should be observable at the Continuous Electron Beam Accelerator Facility. With sufficiently low thresholds on the ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{-}}$ invariant mass a branching ratio of ∼${10}^{\mathrm{-}5}$ may be observed for Δ→${\mathit{Ne}}^{+}$${\mathit{e}}^{\mathrm{-}}$. For the Δ→N${\mathrm{\mu }}^{+}$${\mathrm{\mu }}^{\mathrm{-}}$ decay mode we predict a branching ratio of 3×${10}^{\mathrm{-}7}$. The dependence of the M1 and E2 amplitudes on the momentum transfer will provide a useful test of chiral perturbation theory which predicts ∼20% variation over the allowed kinematic range.

We study, in the framework of the Skyrme model, the consistency between πN form factors and the NN potential based on the product ansatz. The results arising from the various approaches do not coincide, in spite of a relative coherence between them when the form factor includes pion refraction. This points to conceptual inconsistencies among the various approaches employed to tackle these problems.

Nonvanishing values of the spin-polarization experimental observables clearly derive from the different spin-dependent interactions, i.e., spin-orbit, spin-spin, and spin-tensor. The explict dependence of selected observables on these interactions is discussed for scattering with the spin structure 1/2+1/2→1/2+1/2.

A microscopic optical model formalism for estimating momentum transfer in intermediate energy heavy ion collisions predicts universal behavior of the transverse component. In particular, for symmetric systems (${\mathit{A}}_{\mathit{p}}$=${\mathit{A}}_{\mathit{T}}$) heavier than niobium, it appears that values of ${\mathit{P}}_{\mathrm{\perp }}$/A are independent of the mass and charge of the colliding nuclei and vary only with impact parameter and incident beam energy. This suggests that momentum transfer per nucleon saturates to some limiting value with increasing mass.

New values are extracted for the deuteron rms matter radius ${\mathit{r}}_{\mathrm{D}}$=1.9547±0.0019 fm and the matter radial deuteron moments 〈${\mathit{r}}^4$〉=54.2±0.1 ${\mathrm{fm}}^4$ and 〈${\mathit{r}}^6$〉=1828±1 ${\mathrm{fm}}^6$ by analyzing the experimental ratio of (e,d) to (e,p) scattering.

Multifragmentation, following the formation of toroidal and bubble nuclei, is observed with an improved Boltzmann-Uehling-Uhlenbeck model for central ${}_{}{}^{92}{}_{}{}^{}\mathrm{Mo}$${+}^{92}$Mo collisions. With a stiff equation of state, simultaneous explosion into several nearly equal fragments in a ringlike manner occurs due to the formation of metastable toroidal nuclei. In contrast, with a soft equation of state, simultaneous explosion into several nearly equal fragments in a volumelike manner occurs due to the formation of metastable bubble nuclei. Experimental signatures for the formation of these exotic shapes are discussed.

We have calculated the ${\mathrm{\beta }}^{+}$ decay of the proton-rich nuclei ${}_{}{}^{44}{}_{}{}^{}\mathrm{V}$ in the full fp-shell valence space. Using the standard quenching factor 0.77 for the Gamow-Teller (GT) operator we obtain a theoretical half-life of 71 ms in good agreement with the experimental value ${\mathit{t}}_{1/2}$=90±25 ms. We also compute the Gamow-Teller strength functions corresponding to the decays of the $2^{+}$ ground state and $6^{+}$ isomer state. Our results indicate that 80% of the total GT strength falls within the ${\mathrm{\beta }}^{+}$ energy window.

The Glauber coherent states are considered as possible candidates for the wave functions of the nucleons clustered in the α particle before decay. It is shown that the center of mass wave function may be easily separated, and the result is in agreement with the previous models. This new approach is applied to study the geometric effect of the nuclear shape on the preformation probability.

The results of a recent study about the role of short-range correlations on the occupation numbers of the shell model orbits in light nuclei are reconsidered by assuming a sort of state dependence of the single particle wave functions in the ‘‘natural orbital’’ representation, which is used for the determination of the occupation probabilities. It turns out that such a treatment leads to a significant reduction of the total depletion of the nuclear Fermi sea. The state dependence of short-range correlations is also discussed.