The angular distributions of the cross section, the proton analyzing power, and all proton polarization transfer coefficients of $\overrightarrow{p}d$ elastic scattering were measured at 250 MeV. The range of center-of-mass angles was $10°–165°$ for the cross section and the analyzing power, and about $10°–95°$ for the polarization transfer coefficients. These are the first measurements of a complete set of proton polarization observables for $\overrightarrow{p}d$ elastic scattering at intermediate energies. The present data are compared with theoretical predictions based on exact solutions of the three-nucleon Faddeev equations and modern realistic nucleon-nucleon potentials combined with three-nucleon forces (3NF), namely, the Tucson-Melbourne (TM) $2\pi$-exchange model, a modification thereof ${(\mathrm{T}\mathrm{M}}^{\prime }$) closer to chiral symmetry, and the Urbana IX model. Large effects of the three-nucleon forces are predicted. The inclusion of the three-nucleon forces gives a good description of the cross section at angles below the minimum. However, appreciable discrepancies between the data and predictions remain at backward angles. For the spin observables the predictions of the TM 3NF model deviate strongly from the other two 3NF models, which are close together, except for $K_y^{y^{\prime }}.$ In the case of the analyzing power all 3NF models fail to describe the data at the upper half of the angular range. In the restricted measured angular range the polarization transfer coefficients are fairly well described by the ${\mathrm{TM}}^{\prime }$ and Urbana IX 3NF models, whereas the TM 3NF model mostly fails. The transfer coefficient $K_y^{y^{\prime }}$ is best described by the Urbana IX but the theoretical description is still insufficient to reproduce the experimental data. These results call for a better understanding of the spin structure of the three-nucleon force and very likely for a full relativistic treatment of the three-nucleon continuum.

The relationship between nuclear temperature and excitation energy of hot nuclei formed by $8\mathrm{GeV}/c$ negative pion and antiproton beams incident on ${}^{197}\mathrm{Au}$ has been investigated with the ISiS $4\pi$ detector array at the BNL AGS accelerator. The double-isotope-ratio technique was used to calculate the temperature of the hot system. The two thermometers used, $(p/d{-}^3\mathrm{He}{/}^4\mathrm{He})$ and $(d/t{-}^3\mathrm{He}{/}^4\mathrm{He}),$ are in agreement below $E^{*}/A\sim 8\mathrm{MeV}$ when corrected for secondary decay. Caloric curves derived from successive segments of the H and He kinetic energy spectra show a systematic decrease in temperature as the kinetic energy bin decreases, consistent with “cooling curve” behavior. When extrapolated to the evaporative-peak region, these results provide good agreement with caloric curves measured for similar systems. The caloric curves from this experiment are also compared with the predictions from the SMM multifragmentation model.

In this work we study the problem of a charged particle, bound in a harmonic-oscillator potential, being excited by the Coulomb field from a fast charged projectile. Based on a classical solution to the problem and using the squeezed-state formalism we are able to treat exactly both dipole and quadrupole Coulomb field components. Addressing various transition amplitudes and processes of multiphonon excitation, we study different aspects resulting from the interplay between $E1\mathrm{}$ and $E2\mathrm{}$ fields, ranging from classical dynamic polarization effects to questions of quantum interference. We compare exact calculations with approximate methods. Results of this work and the formalism we present can be useful in studies of nuclear reaction physics and in atomic stopping theory.

Previous continuum-discretized coupled-channel (CDCC) calculations comparing ${}^6\mathrm{Li}{+}^{208}\mathrm{Pb}$ with ${}^7\mathrm{Li}{+}^{208}\mathrm{Pb}$ suggested that the observed difference in the dynamic polarization potentials for these systems at bombarding energies close to the Coulomb barrier was due to the $\sim 1\mathrm{MeV}$ difference between the $\alpha +d$ and $\alpha +t$ breakup thresholds for ${}^6\mathrm{Li}$ and ${}^7\mathrm{Li}$ rather than differences in their ground state structures. In this work we compare CDCC calculations for ${}^7\mathrm{Be}{+}^{208}\mathrm{Pb}$ with similar calculations for ${}^7\mathrm{Li}{+}^{208}\mathrm{Pb}$ to further test whether the breakup threshold is the controlling factor in determining the near-barrier behavior of the dynamic polarization potential. We conclude that this is indeed the case and that ${}^7\mathrm{Be},$ with its lower breakup threshold, will behave like ${}^6\mathrm{Li}$ rather than ${}^7\mathrm{Li},$ in that it will not exhibit a threshold anomaly. Furthermore, we predict a clear experimental signature for this difference in behavior: the lack of a pronounced Coulomb rainbow in the ${}^7\mathrm{Be}$ elastic scattering angular distributions. It is proposed that elastic scattering measurements of ${}^7\mathrm{Be}{+}^{208}\mathrm{Pb}$ be carried out at two energies near the Coulomb barrier to confirm this conclusion.

The dependence of the heavy-ion interaction on the orientation is investigated for the cold fusion of two (spherical or deformed) nuclei leading to a superheavy element. In contrast to the case of cold fission, when the fragments are exclusively emerging at scission in pole-pole configuration, in the case of cold fusion the fragments are not necessarily limited to a particular reciprocal orientation and capture can occur also for configurations other than the pole-pole configuration. The occurrence of minima in the driving potential as a function of the interfragment distance and of the mass asymmetry is discussed for several orientations.

Irradiation experiments were performed at the HIMAC (heavy-ion medical accelerator in Chiba) facility, National Institute of Radiological Sciences. The radioactive spallation products in a thick Cu target were obtained for 230 and 100 MeV/nucleon Ne, C, He, and p ions. The gamma-ray spectra from irradiated Cu pieces inserted into the composite Cu target were measured with a high-purity Ge detector. From the gamma-ray spectra, we obtained the variation of radioactive yields with depth in the Cu target and the mass-yield distribution of nuclides produced on the surface. The results show that the cross sections strongly depend on the projectile mass and, consequently, on the mass number difference between Cu and the produced nuclides. The most important feature of the present data is the extraction of the energy dependence of the cross sections. The measured cross sections were fitted to a modified form of Rudstam’s semiempirical formula in order to evaluate the cross sections of unmeasured nuclides. These estimated cross sections were added to the experimental yields for each mass number and the total mass yield and isobaric charge distributions, and the slope of the mass-yield distribution were obtained.

Using a hadron and string cascade model JPCIAE we have investigated the dependence of event-by-event charge fluctuations on (pseudo)rapidity window size, final state interaction, resonance decay, centrality, and reaction energy for Pb+Pb collisions at SPS and LHC energies and for Au+Au collisions at RHIC energies. The JPCIAE results of the charge fluctuations as a function of rapidity window size in Pb+Pb collisions at SPS energies are compared with the preliminary NA49 data. Comparisons with PHENIX and STAR data in Au+Au collisions at $\sqrt{s_{\mathrm{nn}}}=130\mathrm{}\mathrm{GeV}$ are also given. It is found that the charge fluctuations hardly depend on collision centrality except for very peripheral collisions and are rather insensitive to the change of reaction energy. Our calculations also show that the charge fluctuations are not strongly affected by the final state interaction and the resonance decay.

We discuss symmetry constraints on the azimuthal oscillations of two-particle correlation (Hanbury–Brown-Twiss interferometry) radii for noncentral collisions between equal spherical nuclei. We also propose a method for correcting in a model-independent way the emission angle dependent correlation function for finite event-plane resolution and angular binning effects.

Excited states in ${}^{139}\mathrm{Xe},$ populated in the spontaneous fission of ${}^{248}\mathrm{Cm},$ were studied by means of prompt-$\gamma$ spectroscopy, using the EUROGAM2 multidetector array. Spins and parities of excited levels were determined experimentally. New information was also obtained for the ${}^{141}\mathrm{Ba}$ nucleus. These data and a reevaluation of the data available in the literature on ${}^{141}\mathrm{Ba}$ and ${}^{143}\mathrm{Ce}$ show that the near-yrast structures of the ${}^{139}\mathrm{Xe},$ ${}^{141}\mathrm{Ba},$ and ${}^{143}\mathrm{Ce}$ nuclei are similar to that in the heavier $N=85\mathrm{}$ isotones. The presence of strong octupole correlations in the ${}^{139}\mathrm{Xe}$ and ${}^{141}\mathrm{Ba}$ nuclei, reported in another recent study, is not supported by the present work. The observed excitations in the $N=85\mathrm{}$ isotones are interpreted as being due to quadrupole and octupole vibrations coupled to the valence-neutron levels.

Experimental data on strong $E1\mathrm{}$ transitions from the ground state in collective nuclei are analyzed. A model based on the idea of cluster-type correlations is suggested to interpret these experimental data. The calculated results show that a cluster mode is responsible for strong $E1\mathrm{}$ transitions in spherical and near deformed nuclei.

In efforts to determine phase transitions in the disintegration of highly excited heavy nuclei, a popular practice is to parametrize the yields of isotopes as a function of temperature in the form ${Y\left(z\right)=z}^{-\tau }f\left(z^{\sigma }\right(T-T_0\left)\right),$ where $Y\left(z\right)\mathrm{}$’s are the measured yields and $\tau ,$ $\sigma ,$ and $T_0$ are fitted to the yields. Here $T_0$ would be interpreted as the phase transition temperature. For finite systems such as those obtained in nuclear collisions, this parametrization is only approximate and hence allows for extraction of $T_0$ in more than one way. In this work we look in detail at how values of $T_0$ differ, depending on methods of extraction. It should be mentioned that for finite systems, this approximate parametrization works not only at the critical point, but also for first-order phase transitions (at least in some models). Thus the approximate fit is no guarantee that one is seeing a critical phenomenon. A different but more conventional search for the nuclear phase transition would look for a maximum in the specific heat as a function of temperature $T_2.$ In this case $T_2$ is interpreted as the phase transition temperature. Ideally $T_0$ and $T_2$ would coincide. We invesigate this possibility, both in theory and from the ISiS data, performing both canonical (T) and microcanonical ${(e=E}^{*}/A)$ calculations. Although more than one value of $T_0$ can be extracted from the approximate parametrization, the work here points to the best value from among the choices. Several interesting results, seen in theoretical calculations, are borne out in experiment.

We show that an event-by-event fluctuation of the ratio of neutral pions or resulting photons to charged pions can be used as an effective probe for the formation of disoriented chiral condensates. The fact that the neutral pion fraction produced in case of disoriented chiral condensate formation has a characteristic extended non-Gaussian shape is shown to be the key factor which forms the basis of the present analysis.

The structure of $\eta$-nucleus bound systems $(\eta$ mesic nuclei) is investigated as one of the tools to study in-medium properties of the ${N\left(1535\right)(N}^{*})$ resonance by using the chiral doublet model to incorporate the medium effects of the $N^{*}$ resonance in a chiral symmetric way. We find that the shape and depth of the $\eta$-nucleus optical potential are strongly affected by the in-medium properties of the $N^{*}$ and nucleon. Especially, as a general feature of the potential, the existence of a repulsive core of the $\eta$-nucleus potential at the nuclear center with an attractive part at the nuclear surface is concluded. We calculate the level structure of bound states in this “central-repulsive and surface-attractive” optical potential and find that the level structure is sensitive to the in-medium properties of the $N^{*}.$ The ${(d,}^3\mathrm{He})$ spectra are also evaluated for the formation of these bound states to investigate the experimental feasibility. We also make comments on the possible existence of halo-like $\eta$ states in $\beta$-unstable halo nuclei.

Properties of spin-polarized isospin asymmetric nuclear matter are studied within the framework of the Brueckner-Hartree-Fock formalism. The single-particle potentials of neutrons and protons with spin up and down are determined for several values of the neutron and proton spin polarizations and the asymmetry parameter. It is found that the single-particle potentials exhibit an almost linear and symmetric variation as a function of these parameters. An analytic parametrization of the total energy per particle as a function of the asymmetry and spin polarizations is constructed. This parametrization is employed to compute the magnetic susceptibility of nuclear matter for several values of the asymmetry from neutron to symmetric matter. The results show no indication of a ferromagnetic transition at any density for any asymmetry of nuclear matter.

We perform large-scale shell model Monte Carlo (SMMC) calculations for many nuclei in the mass range $A=56\mathrm{}–65$ in the complete ${\mathrm{pfg}}_{9/2}{d}_{5/2}$ model space using an effective quadrupole-quadrupole+pairing residual interaction. Our calculations are performed at finite temperatures between $T=0.33\mathrm{}$ and 2 MeV. Our main focus is the temperature dependence of the symmetry energy which we determine from the energy differences between various isobaric pairs with the same pairing structure and at different temperatures. Our SMMC studies are consistent with an increase of the symmetry energy with temperature. We also investigate possible consequences for core-collapse supernova events.

The pseudorapidity distributions of particles produced in high-energy collisions are analyzed by the thermalized two-cylinder model. The calculated results are compared and found to be in agreement with the experimental data of Au-Au collisions at $\sqrt{s}=130A\mathrm{GeV}.$

Ground state properties of finite nuclei ${(}^{16}\mathrm{O}$ and ${}^{40}\mathrm{Ca})$ are evaluated from realistic nucleon-nucleon interactions. The calculations are based on the Brueckner-Hartree-Fock approximation. Special attention is paid to the role of the energy spectrum for the particle states, in particular, for those close to the Fermi energy. Additional binding energy is obtained from the inclusion of the hole-hole scattering term within the framework of the Green function approach. Results for the energy distribution of the single-particle strength and the sensitivity to the nucleon-nucleon interaction are investigated. For that purpose three modern nucleon-nucleon interactions are employed: the Argonne V18, the charge-dependent Bonn potential, and a realistic nucleon-nucleon interaction which is based on chiral perturbation theory and which has recently been fitted by the Idaho group.