Exclusive measurements of neutrons and charged products have been performed using a combination of 4π neutron and 4π charged-particle detectors. The maximum observed energy dissipation corresponds to only approximately one-half of the available kinetic energy. For any degree of dissipation, the velocity distributions of charged particles are characteristic of sequential emission following binary collisions. The data imply that central collisions also lead to bimodal emission patterns or that they are not sufficiently well isolated by the requirement of high particle multiplicities.

The energy spectrum and the angular dependence relative to the fission direction of photons in the energy region between 2 and 40 MeV have been measured for the spontaneous fission of ${}_{}{}^{252}{}_{}{}^{}\mathrm{Cf}$. A large anisotropy was found in the energy region 8 to 12 MeV implying that photons in this region are emitted from a nuclear system which is highly elongated along the fission axis.

A statistical method to analyze the gamma decay of excited, rapidly rotating nuclei is presented. It is based on the fact that the cooling path of these systems goes through regions of both suppressed and enhanced fluctuations typical of large and low level density, respectively. The method is applied to the study of the high-spin quasicontinuum of ${}_{}{}^{167,168}{}_{}{}^{}\mathrm{Yb}$.

We present the first polarization measurements for pion absorption on a nucleus heavier than the deuteron. The polarization of protons resulting from ${\mathrm{\pi }}^{+}$ absorption in the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ was measured at bombarding energies of 120 and 250 MeV. Protons from absorption in a quasideuteron were selected by applying kinematical constraints. A significant discrepancy was observed between the experimental results and theoretical predictions. At 120 MeV the measured polarizations for ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ are consistent with those of the deuteron. At 250 MeV the angular distribution of the polarization is significantly different than for the deuteron, showing sensitivity to the nuclear density, and thus may be sensitive to short range correlations between nucleons.

We present a calculation of antiproton yields in Si+Al and Si+Au collisions at 14.5A GeV in the framework of the relativistic quantum molecular dynamics approach (RQMD). Multistep processes lead to the formation of high-mass flux tubes. Their decay dominates the initial antibaryon yield. However, the subsequent annihilation in the surrounding baryon-rich matter suppresses the antiproton yield considerably: Two-thirds of all antibaryons are annihilated even for the light Si+Al system. Comparisons with preliminary data of the E802 experiment support this analysis.

A new microscopic simulation method of heavy-ion collisions is formulated by incorporating the two-nucleon collision process into the antisymmetrized version of molecular dynamics. This method can describe quantum-mechanical features such as shell effects. The fragment mass distribution of the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${+}^{12}$C reaction at 28.7 MeV/nucleon is shown to be reproduced very well by this new method combined with the treatment of statistical cascade decays of excited fragments, which verifies the usefulness of the new method.

We report measurements of asymmetries in quasielastic scattering of polarized electrons from polarized ${\mathrm{He}}^3$ at ${\mathrm{Q}}^2$=-0.2 GeV/c${)}^2$. We measure ${\mathrm{A}}_{\mathrm{T}\prime }$=(-2.6±0.9±0.46)% and ${\mathrm{A}}_{\mathrm{TL}\prime }$=(+1.75±1.2±0.31)%. The asymmetry ${\mathrm{A}}_{\mathrm{T}\prime }$ depends predominantly on the previously measured neutron magnetic form factor and provides a test of theories of spin-dependent quasielastic scattering. Our result for ${\mathrm{A}}_{\mathrm{T}\prime }$ is consistent with a previously reported measurement and suggests that the current theoretical picture is incomplete and final-state-interaction and meson-exchange corrections are necessary if the electric form factor of the neutron is to be reliably extracted from the asymmetry of ${\mathrm{A}}_{\mathrm{TL}\prime }$.

Using $4\pi$ data from the Bevalac streamer chamber, we study azimuthal correlations for fragment pairs and higher-order multiplets. We point out that previous studies of sideward flow have not ruled out the possibility that the effect is dominated by a small number of correlated fragments in each event, as opposed to being a collective motion to which most or all fragments contribute. Based on a simulation, we infer that more than 70% of the forward-going fragments from collisions of Ar on Pb at 0.4A GeV carry a component of the collective motion.

A relativistic hadronic cascade is used to simulate collisions of Si on Au at 14.6 GeV/c per nucleon. When proper account is taken of resonances produced in elemental hadron-hadron collisions this cascade quantitatively describes most published E802 data from the BNL Alternating Gradient Synchrotn including the problematic proton transverse mass distributions. No medium effects seem required to explain the apparent enhancement of strangeness production nor any other features of the data.

We show a possible large spin polarization of the nuclei produced by one-nucleon-transfer heavy-ion reactions and investigate its origin. The asymmetry of the particle-γ angular correlation is also calculated for the ejectile and γ ray emitted from the spin polarized nucleus.

Preequilibrium parton scattering is shown to make an important contribution to the charm production in relativistic heavy ion collisions. In contrast to the gluon shadowing effect in the initial parton scattering, the enhancement of the final total open charm in the central region due to preequilibrium production could be used as a measure of the thermalization time of the dense partonic system.

The origin and consequences of pseudospin symmetry in nuclear physics, which is exact for an oscillator potential with one-body orbit-orbit (${\nu }_{\mathit{l}\mathit{l}}$) and spin-orbit (${\nu }_{\mathit{l}\mathit{s}}$) interaction strengths in the ratio μieq2${\nu }_{\mathit{l}\mathit{l}}$/${\nu }_{\mathit{l}\mathit{s}}$=0.5, are considered. Specifically, the ${\nu }_{\mathit{l}\mathit{s}}$≊4${\nu }_{\mathit{l}\mathit{l}}$ condition is consistent with relativistic mean-field results and a pseudo LS coupling scheme. When deformation dominates, pseudospin extends to pseudo SU(3), which is applicable to superdeformation.

The polarization of quasifree Λ hyperons produced by the (${\mathrm{\pi }}^{+}$${\mathit{K}}^{+}$) reaction on ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and on the deuteron was measured for the first time. The asymmetry of pions from weak decay of the Λ hyperon was used to determine the polarization. The polarization for the deuterium target was found to be consistent with that for the elementary n(${\mathrm{\pi }}^{+}$,${\mathit{K}}^{+}$)Λ reaction. The polarization of the Λ produced by the quasifree process from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ is consistent with that for the elementary reaction, which demonstrates that the spin characteristics of the elementary reaction are not modified by the nuclear medium.

The multifragment emission of ‘‘completely characterized’’ events in the ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$${+}^{40}$Ca system at 35 MeV/nucleon has been compared to the predictions of several models. The observed multifragment emission is not in agreement with models based on conventional statistical binary decay, but is in agreement with both a simultaneous multifragmentation model and a sequential emission model in which expansion is treated.

We present a three-dimensional statistical field theory of density fluctuations motivated by the Ginzburg-Landau theory of superconductivity. The free-field theory yields Yukawa-type two-particle cumulant correlations and no higher-order ones, in agreement with high-energy heavy-ion data. We mention the extension of our model to describe hadronic reactions and indicate how it may be related to QCD. We predict the multiplicity distribution of particles produced in heavy-ion collisions.

Quantum corrections to the mean-field equation of state for nuclear matter are estimated in a lattice simulation of quantum hadrodynamics. In contrast with the standard coordinate-space methods used in lattice QCD, the calculations are carried out here in momentum space and on nonhypercubic (irregular) lattices. The quantum corrections to the known mean-field equation of state were found to be considerable.

Measurements of the Drell-Yan process and of charmonium and bottomonium production at CERN and Fermilab show a depletion at high Feynman x in large relative to small nuclear targets. We can attribute this depletion to energy loss of initial and final states, provided that the loss is (dE/dz${)}_{\mathrm{Drell}\mathrm{-}\mathrm{Yan}}$=4/9 (dE/dz${)}_{\mathrm{charm}}$∼1.5 GeV/fm at the highest ${\mathit{x}}_{\mathit{F}}$ measured. This small loss is magnified in the differential cross section due to the strong behavior ∼(1-x${)}^{\mathit{n}}$ of the projectile’s structure functions at large x.

The charge distribution of nuclear fragments for the nonfissile events of ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ at 0.96A GeV in nuclear emulsion is fitted with a power law. The method of scaled factorial moments is used to study fluctuations in the nuclear fragmentations. An intermittent behavior is found in the data, but no clear evidence of critical phenomenon is observed in nuclear fragmentation.

Classical bound-state solutions for the baryon number =2 sector of the Skyrme model have been found by numerical simulation in 3+1 dimensions. The Bohr-Sommerfeld level of quantization is implemented. Properties of the deuteron obtained by quantization about the periodic classical solution improve on previous work based on quantization about the minimum energy static toroidal configuration.

The damping of dipole and quadrupole motion in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ and ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ at zero and finite temperature is studied including particle-particle and particle-hole interactions to all orders of perturbation. We find that the dipole dynamics in these light nuclei is well described in terms of mean-field theory (time-dependent Hartree-Fock), while the quadrupole motion is strongly damped through the coupling to more complicated configurations. Both the centroid and the damping width of the quadrupole and dipole giant resonances show a clear stability with temperature as a consequence of the weakening of the interaction, which contrasts with the increase of the phase space.