A new method to construct hyperspherical functions basis for A identical particles, beyond the minimal approximation, is presented. This method is based on the link between the hyperspherical function method (HSFM) and the oscillator no-core shell model and uses a Slater determinant representation of the hyperspherical functions. It is shown that, because of this representation, the HSFM matrix elements are related to the inverse Laplace transforms of the oscillator shell model matrix elements, on the condition that the center-of-mass motion and the hyperradial excitations are removed from the shell model states. The applicability of the proposed method is demonstrated for the case of the ${}^{3–7}\mathrm{H}$ and ${}^{4–10}\mathrm{He}$ isotopes.

Excited states in ${}^{70}\mathrm{Br}$ were populated in the ${}^{40}\mathrm{Ca}{(}^{32}\mathrm{S},pn)$ reaction at $E_{\mathrm{beam}}=80\mathrm{}–100\hspace{0.5em}\mathrm{MeV}$ and the ${}^{40}\mathrm{Ca}{(}^{36}\mathrm{Ar},\alpha pn)$ reaction at $E_{\mathrm{beam}}=145\mathrm{}\hspace{0.5em}\mathrm{MeV}.$ The resulting gamma decay was detected using the Gammasphere array triggered by a 30-element neutron detector. The cross-bombardment allowed the unambiguous assignment of levels to ${}^{70}\mathrm{Br},$ comprising a total of 32 states built both on the $J^{\pi }{=0\mathrm{}}^{+}$ ground state and a previously known $J^{\pi }{=9\mathrm{}}^{+}$ isomer, which is located at an excitation energy of 2293 keV by the observation of linking transitions. The structures are discussed within the context of the two-quasiparticle plus rotor model, the IBM-4 model and the cranked Nilsson-Strutinsky formalism. The nonobservation of a doublet of $J=0,$ $T=1\mathrm{}$ and $J=1,$ $T=0\mathrm{}$ states at low excitation in ${}^{70}\mathrm{Br}$ is indicative that $T=0\mathrm{}$ proton-neutron pairing strength is weak in comparison to $T=1\mathrm{}$ pairing.

An improved quantum molecular dynamics model is developed. By using this model, the properties of ground state of nuclei from ${}^6\mathrm{Li}$ to ${}^{208}\mathrm{Pb}$ are described very well with one set of parameters. The fusion reactions for ${}^{40}\mathrm{Ca}{+}^{90}\mathrm{Zr},$ ${}^{40}\mathrm{Ca}{+}^{96}\mathrm{Zr},$ and ${}^{48}\mathrm{Ca}{+}^{90}\mathrm{Zr}$ at energies near the barrier are studied by this model. The experimental data of the fusion cross sections for ${}^{40}\mathrm{Ca}{+}^{90,96}\mathrm{Zr}$ at energies near the barrier are reproduced remarkably well without introducing any new parameters. The mechanism for the enhancement of the fusion cross sections for neutron-rich nuclear reaction near barrier is analyzed.

The absolute strength of the $E_R=338\mathrm{}\hspace{0.5em}\mathrm{keV}$ resonance for ${}^{23}\mathrm{Na}(p,\alpha {)}^{20}\mathrm{Ne}$ has been determined. The experiment was carried out by measuring the number of resonant $\alpha$ particles, integrated over the yield curve, simultaneously with the number of Rutherford scattered protons. The method applied in the present work is independent of target stoichiometry, uniformity, stopping power, beam straggling, and current integration. For the resonance strength, we obtained a value of $\omega \gamma =(7.16\mathrm{}\pm 0.29)\times {10}^{-2}\hspace{0.5em}\mathrm{eV}.$ Previous results are systematically higher, because the change of target stoichiometry under proton bombardment was not taken into account. With proper consideration, the present method can also be applied to other low-energy $(p,\alpha )$ resonances.

We predict $W^{\pm }$ and $Z^0$ transverse momentum distributions from proton-proton and nuclear collisions at Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider (LHC) energies. A resummation formalism with power corrections to the renormalization group equations is used. The dependence of the resummed QCD results on the nonperturbative input is very weak for the systems considered. Shadowing effects are discussed and found to be unimportant at RHIC, but important for LHC. We study the enhancement of power corrections due to multiple scattering in nuclear collisions and numerically illustrate the weak effects of the dependence on the nuclear mass.

Results of a combined analysis are presented for the production of $\omega$ and $\phi$ mesons in $\pi N$ reactions in the near-threshold region using a conventional “nonstrange” dynamics based on processes that are allowed by the nonideal $\omega -\phi$ mixing. We show that the interferences of the t channel (meson exchange) and s, u channels (nucleon and nucleon-resonances) differ significantly for the $\omega$ and $\phi$ production amplitudes. This leads to a decrease of the relative yields, in comparison with the expectations based on a one-component amplitude with standard $\omega -\phi$ mixing. We find a strong and nontrivial difference between observables in $\omega$ and $\phi$ production reactions caused by the different roles of the nucleon and nucleon-resonance amplitudes. A series of predictions for the experimental study of this effect is presented.

We investigate $p3/2\mathrm{}$ strengths in ${}^{41}\mathrm{Sc}$ and ${}^{40}\mathrm{Sc},$ and use the results to estimate proton widths in ${}^{40}\mathrm{Sc},$ and hence reaction rates for ${}^{39}\mathrm{Ca}{(p}_{,}\gamma ).\mathrm{}$

Experimental cross sections at high energies for the ${}^{12}\mathrm{C}{(}^{16}\mathrm{O}{,}^{15}\mathrm{N}/\mathrm{O})X$ and ${}^{12}\mathrm{C}{(}^{12}\mathrm{C}{,}^{11}\mathrm{B}/\mathrm{C})X$ nucleon removal reactions are reduced by factors $R_s=0.49\mathrm{}–0.68$ relative to calculations in the shell model and eikonal reaction theory. For protons, this is exactly what has been found in the ${(e,e}^{\prime }p)$ reaction. We suggest that nuclear knockout has potential for extending the measurement of precise orbital occupancies to neutron states and to a wide range of nuclei including rare radioactive species. The halo proton in radioactive ${}^8\mathrm{B}$ turns out to have a stronger presence in the wave function with $R_s=0.88\mathrm{}\left(4\right).$

A stack of annular detectors made of high purity germanium was used to measure $p\overrightarrow{p}\mathrm{pp}{\pi }^0$ differential cross sections at a beam momentum of 850 $\mathrm{MeV}/c.\mathrm{}$ A total cross section of $\sigma =9.1\mathrm{}\pm 1.1\hspace{0.5em}\mu \mathrm{b}$ is deduced. The fitted distribution of different partial waves to the world total cross section data and to the present differential cross sections favors an approach without low-energy approximations, with the standard value for the final state interaction scattering length, and an important contribution from an intermediate $N\Delta$ state.

Several observables in two-body deuteron photodisintegration are investigated in the framework of the Bethe-Salpeter formalism. Apart from keeping the Lorentz covariance throughout, special attention is paid to inclusion of both the positive-energy and negative-energy partial-wave components of the deuteron state. Using the Bethe-Salpeter equation for the deuteron in the ladder approximation with one-boson exchanges as a driving term, the contribution of the negative-energy states is studied for the unpolarized differential cross section as well as for linear photon and tensor target asymmetries. These states are found to have an impact on the observables and, thus, should be taken into account in a complete theoretical treatment of the reaction in the intermediate energy regime.

Based on the dinuclear system concept, the role of bending vibrations in creation of the angular momentum of the primary fission fragments is investigated. For ${}^{252}\mathrm{Cf}$ spontaneous fission, the angular momenta of the fragments are calculated as a function of the neutron multiplicity and compared with available experimental data.

An algebraic model is developed to calculate the $T=0\mathrm{}$ and $T=1\mathrm{}$ ground-state binding energies of $N=Z$ nuclei. The method is tested in the $\mathrm{sd}$ shell and is then extended to the 28-50 shell that is currently the object of many experimental studies.

We adopt the quasiparticle-phonon model to investigate the microscopic structure of some low-lying states recently discovered in nuclei around shell closure. The study determines quantitatively the phonon content of these states and shows that their main properties are determined by a subtle competition between particle-particle and particle-hole quadrupole interactions and by the interplay between orbital and spin-flip motion. The results are in overall agreement with experiments and consistent with the interacting boson model and shell model calculations.

The ground-state and pairing properties of Pr $\mathrm{}(Z=59\mathrm{})\mathrm{}$ isotopes are investigated in the relativistic mean-field (RMF) theory. The pairing correlations are studied in the Bardeen-Cooper-Schrieffer (BCS) approximation, and the pairing forces are taken to be isospin dependent. The “blocking” method is adopted to deal with unpaired odd nucleons. The occupation numbers in the continuum for Pr isotopes are studied, which may indicate the domain of the validity of BCS theory. The positions of the neutron and proton drip lines are investigated. It is shown that the RMF-BCS theory provides a good description of the binding energy, isotope shifts, and deformation of nuclei over a large range of Pr isotopes, which are in good agreement with those obtained in the finite-range droplet model.

A systematic study of the population probabilities of microsecond isomers produced following the fragmentation of ${}^{208}\mathrm{Pb}$ projectiles at 1 GeV/nucleon has been undertaken at the SIS/FRS facility at GSI Darmstadt. Gamma decays from approximately 20 isomeric states, mainly in the rare-earth and transitional nuclei with $A\sim 180,$ were identified and the corresponding isomeric ratios deduced. The results are compared with a model based on the statistical abrasion-ablation description of relativistic fragmentation and simple assumptions concerning gamma cascades in the final nucleus (sharp cutoff). The model is found to represent an upper limit for the population of isomeric states in relativistic projectile fragmentation.

Angular distributions for the elastic and inelastic scattering of pions by ${}^{40,42,44,48}\mathrm{Ca}$ and ${}^{54}\mathrm{Fe}$ at 116, 180, and 292.5 MeV have been analyzed. The equivalent local optical model calculations have been carried out for elastic and inelastic scattering of ${\pi }^{\pm }$ leading to the lowest $2^{+}$ and $3^{-}$ states of these nuclei. Good reproductions of the data are obtained for these nuclei without adjusting any free parameters in the optical potential. Reaction cross sections and deformation lengths are consistent with other calculations of these quantities.

Experimental data from the reaction of an $8.0\mathrm{GeV}/c$ ${\pi }^{-}$ beam incident on a ${}^{197}\mathrm{Au}$ target have been analyzed in order to investigate the breakup time scale for hot residues. Helium nuclei angular distributions and energy spectra supported by a momentum tensor analysis suggest that at large excitation energy, above $3-5\mathrm{M}\mathrm{e}\mathrm{V}/\mathrm{n}\mathrm{u}\mathrm{c}\mathrm{l}\mathrm{e}\mathrm{o}\mathrm{n},$ highly excited heavy fragments are separated promptly after the thermalization. A binary fission-like mechanism fits the experimental data at low excitation energies, but seems unable to reproduce the data at excitation energies above $3-5\mathrm{M}\mathrm{e}\mathrm{V}/\mathrm{n}\mathrm{u}\mathrm{c}\mathrm{l}\mathrm{e}\mathrm{o}\mathrm{n}.$

Fragmentation of secondary beams of neutron-rich, unstable ${}^{19,20,21}\mathrm{O}$ isotopes at beam energies near 600 MeV/nucleon was studied by measuring the production cross sections for carbon, nitrogen, and oxygen fragments. Data for stable ${}^{17,18}\mathrm{O}$ beams were obtained as well. The measurements serve to illuminate the isospin dependence of the fragmentation process. The experimental results are compared to those from empirical parametrization and those from abrasion-ablation models.

Using the recently proposed $\mathrm{gg}{\eta }^{\prime }$ effective vertex, we investigate the production of ${\eta }^{\prime }$ from gluon fusion in $\mathrm{pA}$ collisions. We show that measuring ${\eta }^{\prime }$ production cross section at moderate $x_{{\eta }^{\prime }}$ yields direct information on the small x gluon distribution function of the nucleus. At RHIC, the smallest accessible x turns out to be ${O(10\mathrm{}}^{-5})$ and at LHC, it is ${O(10\mathrm{}}^{-8}).\mathrm{}$ Therefore, ${\eta }^{\prime }$ is an excellent probe of the color glass condensate.

We investigate the symptoms of broken rotational invariance, caused by the use of light front dynamics, for deuterons obtained using one- and two-pion-exchange potentials. A large mass splitting between states with $m=0\mathrm{}$ and $m=1\mathrm{}$ is found for the deuteron obtained from the one-pion-exchange potential. The size of the splitting is smaller when the chiral two-pion-exchange (TPE) potential is used. When the TPE potential constructed without chiral symmetry is used, the deuteron becomes unbound. These results arise from significant relativistic effects that are much larger than those of the Wick-Cutkosky model because of the presence of the tensor force.