Potentials are obtained using a WKB inverse scattering technique that is based upon S functions derived from strong absorption model fits to the elastic-scattering cross sections for 1503 MeV ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ ions on ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$. A systematic study of the mass (charge) dependence of the heavy ion nuclear potential at this energy is the result. In this context the dependence of the extracted nuclear potential on the assumed Coulomb interaction between the heavy ions is also considered. With increasing target mass the choice of representative Coulomb field is important in specification of the hadronic interaction component of the inversion potential.

A recent treatment of first-forbidden ${\mathrm{\beta }}^{\mathrm{-}}$ decay in the lead region is extended to ${\mathrm{\beta }}^{+}$ decay and electron capture. The modified Kuo-Herling shell-model interaction recently described by Warburton and Brown is used to calculate wave functions and observables for ${}_{}{}^{211}{}_{}{}^{}\mathrm{Po}$. The log${\mathit{f}}_0$t values for the ${}_{}{}^{211}{}_{}{}^{}\mathrm{Bi}$(9/$2^{\mathrm{-}}$)${\to }^{211}$Po(9/$2^{+}$) ${\mathrm{\beta }}^{\mathrm{-}}$ transition and the electron capture of ${}_{}{}^{211}{}_{}{}^{}\mathrm{At}$(9/$2^{\mathrm{-}}$) into the 9/2 ${}_1{}^{+}{}_{}{}^{}$ and 11/2 ${}_1{}^{+}{}_{}{}^{}$ states of ${}_{}{}^{211}{}_{}{}^{}\mathrm{Po}$ are predicted to be 6.008, 5.891, and 5.850 as compared to the experimental values of 6.026±0.017, 5.960±0.008, and 5.831±0.090, respectively. The wave functions and spectrum of ${}_{}{}^{211}{}_{}{}^{}\mathrm{Po}$ are calculated in the Kuo-Herling model space. The yrast spectrum is presented for comparison to anticipated results from fusion-evaporation reaction studies. The experimental ${}_{}{}^{210}{}_{}{}^{}\mathrm{Po}$(d,p${)}^{211}$Po spectroscopic factors are quite accurately reproduced.

An analysis of low-lying collective states in ${}_{}{}^{110,112,114}{}_{}{}^{}\mathrm{Cd}$ has been performed within the framework of the interacting proton-neutron boson model. The influence of model parameters on level schemes and electromagnetic properties has been investigated, in particular, as far as the breaking of F-spin symmetry is concerned. The $2_3^{+}$ state is suggested as a relatively pure F=${\mathit{F}}_{\max }$-1 (‘‘mixed-symmetry’’) state in the three isotopes.

Giant dipole resonance (GDR) γ rays in coincidence with fission fragments were measured in the reactions ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${+}^{208}$Pb at 120 and 140 MeV, ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$${+}^{196}$Pt at 150 MeV, and ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{\mathrm{nat}}$W at 185 MeV. γ-ray–fission angular correlation measurements for ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${+}^{208}$Pb (120 and 140 MeV) and ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{\mathrm{nat}}$W confirm the strong contribution of prescission γ rays to the total γ-ray spectrum. The data were analyzed with a modified statistical model code which includes the effects of nuclear dissipation in the fission process, γ decay at equilibrium and between saddle and scission, and the decay of the mononucleus formed in quasifission reactions. The extracted value for the nuclear friction coefficient of γ=10±3 at temperatures between 1 and 2 MeV is much larger than the upper limit for the ground state and indicates strongly overdamped large-scale mass motion. The extracted total fission time scale ${\mathrm{\tau }}_{\mathrm{fiss}}$(γ=10)≃2.9×${10}^{\mathrm{-}19}$ s at 64 MeV excitation energy agrees with that extracted from recent neutron multiplicity experiments. A strong dependence of the GDR γ-ray yield on the target-projectile mass asymmetry is interpreted in terms of the quasifission process. γ-ray spectra and correlations could be fitted with the assumption of a GDR contribution from the mononucleus but required an arbitrary reduction of the total fission fragment excitation energy by 30 MeV. The quasifission lifetime was estimated to ${\mathrm{\tau }}_{\mathrm{qf}}$=(2–9)×${10}^{\mathrm{-}20}$ s.

Cross sections and differential recoil range distributions have been measured for 22 spallation products formed in the interaction of 120 MeV ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ with ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$. A Monte Carlo code has been produced that accounts for complete fusion as well as the transfer of α particles and ${}_{}{}^8{}_{}{}^{}\mathrm{Be}$. The results of the calculation compare very well with the experimental data. Incomplete fusion is found to account for more than one-half of nonfission events, and preequilibrium emission of fast nucleons is essential to a full description of the reaction.

Rapidity and transverse momentum distributions of ${\mathrm{\pi }}^{\mathrm{-}}$, ${\mathit{K}}^{\pm }$, and p have been computed for p+Be, p+Au, and Si+Au collisions at 14.6A GeV with the Monte Carlo quark-gluon string model (QGSM). The calculations are compared to experimental data at the same energy. The QGSM reproduced the shapes and approximately absolute values of the minimum bias rapidity distribution for all particles except the pions in p+Au data. The model also reproduced the rapidity distribution for protons and ${\mathit{K}}^{+}$ in the central Si+Au collisions. However, we overestimated the enhancement at low ${\mathit{p}}_{\mathit{t}}$ for pions and negative kaons. As a consequence, the QGSM also produces an excess of pions and ${\mathit{K}}^{\mathrm{-}}$ in the rapidity distribution below y=2, and predicted an overall ${\mathit{K}}^{+}$/${\mathrm{\pi }}^{+}$ enhancement by a factor of 1.4–1.9 as compared to pp data, instead of a factor of 4 as obtained by the E802 Collaboration.

We have searched for high energy γ rays emitted from the spontaneous fission of ${}_{}{}^{252}{}_{}{}^{}\mathrm{Cf}$. This search was carried out by two methods: the measurement of high energy γ rays in coincidence with fission fragments, and the measurement of high energy γ rays in coincidence with any other γ ray. The first of these two methods allowed us to establish a direct correlation between high energy γ rays and fission fragments. For the fission-fragment/γ-ray measurement, we were able to set an upper limit at the 95% confidence level of 1.8×${10}^{\mathrm{-}6}$ photon per fission for the integrated yield of γ rays with an energy greater than 30 MeV. Additionally, we have established an upper limit at the 95% confidence level of 1.0×${10}^{\mathrm{-}5}$ photon per fission for the integrated yield of photons with energy greater than 30 MeV from the γ-γ measurement. These results are shown to be consistent with a classical model estimate of the upper limit of γ rays produced by a nucleus-nucleus bremsstrahlung process arising from the Coulomb acceleration of the fission fragments.

This paper mainly deals with some important features of compound multiplicity in the inelastic nuclear reactions induced by 4.5A GeV/c carbon and silicon ions in nuclear emulsion. The characteristics of this parameter observed in the present study are compared with the corresponding values obtained for proton-emulsion interactions at the same incident momentum per nucleon. The average compound multiplicity is found to vary linearly with black and heavy particle multiplicities. Finally, the compound multiplicity distributions for carbon- and silicon-emulsion interactions are observed to obey a Koba-Nielsen-Olesen (KNO) type of scaling law.

Inclusive and semiexclusive experimental spectra for transfer reactions leading to continuum final states of the target nucleus contain contributions from different kinds of reactions like breakup and transfer to single-particle and compound nucleus resonance states of the target. We use a theoretical approach already discussed in previous publications to calculate energy spectra for transfer to ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ continuum final states. We distinguish the breakup and absorption components of the spectra and discuss the initial state and energy dependence.

The momentum-space treatment of the Coulomb interaction within the framework of the Watson multiple-scattering expansion is derived and tested numerically. By neglecting virtual Coulomb excitations and higher-order terms, the lowest-order optical potential for proton-nucleus scattering is shown to be the sum of the convolutions of a two-body nucleon-nucleon t matrix with the nuclear density and the point Coulomb interaction with the nuclear charge density. The calculation of the optical potential, as well as the treatment of the Coulomb interaction, is performed entirely in momentum space in an exact and numerically stable procedure. Elastic-scattering observables are presented for ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ at energies up to 500 MeV. Comparisons are made with approximate treatments of the Coulomb interaction. The interference of nonlocality effects in the nuclear optical potential with different treatments of the Coulomb interaction is investigated.

Effects of the coupling to ${}_{}{}^6{}_{}{}^{}\mathrm{\alpha }$+d nonresonant continuum states on polarized ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ scattering at ${\mathit{E}}_{\mathrm{lab}}$≃20–100 MeV are investigated in the framework of the continuum-discretized coupled-channels (CDCC) method which takes into account the resonant and nonresonant α-d breakup states of ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$. A convergence of the calculated analyzing powers of ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ elastic scattering against the size and the discretization of the breakup continuum is examined. The resulting model space of the breakup states consists of the α-d S-wave (l=0), P-wave (l=1), and D-wave (l=2) states up to the α-d relative momentum of k=1.2 ${\mathrm{fm}}^{\mathrm{-}1}$. The results of the CDCC calculation show that the effects of the nonresonant breakup states are quite as significant on the analyzing powers as those of the resonant breakup states.

The nucleon-nucleus interaction is considered within the framework of the resonating-group method (RGM), but with the simplifying assumptions of omitting target-recoil effects and core-exchange contributions. The resulting model, called model K, contains then only direct and knock-on-exchange terms. Comparisons between RGM and model-K results in n+α, n${+}^{16}$O, and n${+}^{40}$Ca systems for bound-state energies, phase shifts, differential scattering cross sections, and polarizations show that model K works very well when the target nucleus has a nucleon number greater than about ten and when the scattering energy is higher than about 10 MeV. Because of the adoption of these simplifying assumptions, general expressions for the nuclear-central, Coulomb, and spin-orbit parts of the nucleon-nucleus nonlocal potential can be analytically derived without much difficulty. These expressions have simple forms and are suitable for a systematic and large-scale analysis of existing scattering data even in cases where heavy target nuclei are involved.

A new treatment of scattering, which conserves the total angular momentum and accounts for differences in n-n, n-p, and p-p cross sections, is proposed for use in the Vlasov-Nordheim (or Boltzmann-Uhling-Uhlenbeck) simulations of heavy-ion collisions. This treatment is used in the classical Vlasov-Boltzmann simulations of the collisions between two equal mass (A=50) nuclei at ${\mathit{E}}_{\mathrm{lab}}$≳400 MeV/nucleon. By comparison with the exact results for such collisions, it is shown to be significantly more accurate than the commonly used method in which the angular momentum is not exactly conserved.

Heavy-ion interaction potentials for 360 MeV ${}_{}{}^{12}{}_{}{}^{}\mathrm{-}_{}^{12}{}_{}{}^{}$C and 1503 MeV ${}_{}{}^{16}{}_{}{}^{}\mathrm{-}_{}^{40}{}_{}{}^{}$Ca are derived from solutions of the fixed energy, inverse scattering problem. A semiclassical (WKB) approximation is used to obtain those solutions when various strong-absorption-model parametrized S functions are defined from fits to the differential cross-section data. The extracted potentials vary significantly in their absorption components within the sensitive radial regions.

Forward and transverse energy spectra and the correlation between these two global variables have been measured for the interaction of 14.6A GeV/c ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ ions with ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$ and ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$. The energy in produced particles near midrapidity is observed to be negatively correlated with forward energy. There is minimal target mass dependence of this correlation for peripheral and semicentral interactions (forward energies>80 GeV). However, the fact that transverse energies for more central collisions in Au become increasingly larger than those in Al (∼50% greater in the limit of zero forward energy), provides evidence for multiple interactions of projectile nucleons in the larger target. The experimental results are discussed in terms of calculations based on a model for nucleus-nucleus interactions.

The effect of nonstatistical fluctuations in ultrarelativistic nuclear collisions is analyzed. We argue that it is a nonlinear effect, which cannot be accounted for by the simple nucleon-nucleon superposition models and may have strong implication on our understanding of the collision dynamics. The presence of spatiotemporal intermittency in the interaction region could explain the essential features of the experimentally observed intermittency patterns (impact parameter and projectile dependence). Assuming that the onset of the spatiotemporal intermittency is due to a higher-order phase transition, detailed calculations are made with the inclusion of the nonideal, inside-outside dynamics and the resonance decay. Also the behavior of the fluctuations during the hydrodynamical evolution is studied. The implication of the fractal structures in space-time for Bose-Einstein (BE) correlations is shown to be very small.

We evaluate the strength of rapidity correlations as measured by bin-averaged multiplicity moments for hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions for comparable c.m. energies √s ∼20 GeV. The strength of the correlation decreases rapidly with increasing complexity of the reaction. Although statistically significant cumulant moments, ${\mathit{K}}_2$, ${\mathit{K}}_3$, and ${\mathit{K}}_4$ are found in hadron-hadron (NA22) collisions, higher moments are strongly suppressed (except for ${\mathit{K}}_3$ in KLM Collaboration proton-emulsion data) when nuclei are involved. When ordinary factorial moments are decomposed into cumulant moments, the former are seen to be dominated by combinatoric contributions of the (experimentally determined) cumulant moment ${\mathit{K}}_2$. Hence rapidity fluctuations and intermittent effects are significantly decreased by the use of nuclei as targets and/or projectiles. This result could possibly be reversed at the onset (at higher energy) of a new phase having strong fluctuations, for example, the long-sought quark-gluon plasma.

We develop a covariant coalescence model for relativistically expanding fireballs formed in high-energy nuclear collisions and apply it to predict the formation rate of light nuclei and antinuclei (d,d¯) as well as of the H dibaryon and the pentaquark ${\mathit{P}}^0$ in relativistic heavy-ion collisions at the CERN Super Proton Synchrotron and the Brookhaven Alternating Gradient Synchrotron Accelerators. For the d¯ and H, our predictions differ significantly from previous results based on a nonrelativistic analysis.

We exploit approximate symmetry under particle-hole conjugation and the systematics associated with a classification scheme (inspired by the neutron-proton interacting boson model) to obtain estimates of binding energies and low-lying excitation energies for even-even r-process nuclei drawn from the major proton and neutron shells, 50<Z<82 and 82<N<126. We anticipate that our simple formalism for binding energies, depending on only six parameters, has an accuracy of ∼0.8 MeV. We argue that the particular dual particle-hole conjugation symmetry required to relate excitation energies in neutron-rich nuclei to the known excitation energies of the corresponding conjugated nuclei holds to within 10% or so.

Cross sections for the production of target fragments in the interaction of silver with 14.6 GeV/nucleon ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ ions have been measured and used to determine the mass-yield distribution. The results are compared with similar data obtained for other high-energy reactions and are generally consistent with factorization.