A transport model is developed to describe hadron emission from a strongly coupled quark-gluon plasma formed in relativistic heavy ion collisions. The quark-gluon plasma is controlled by ideal hydrodynamics, and the hadron motion is characterized by a transport equation with loss and gain terms. The two sets of equations are coupled to each other, and the hadronization hypersurface is determined by both the hydrodynamic evolution and the hadron emission. The model is applied to calculate the transverse momentum distributions of mesons and baryons, and most of the results agree well with the experimental data at RHIC.

New cross sections for the reaction $\mathit{ep}\to e^{\text{'}}\eta p$ are reported for total center-of-mass energy $W=1.5\text{−}2.3$ GeV and invariant squared momentum transfer $Q^2=0.13\text{−}3.3$ GeV${}^2$. This large kinematic range allows the extraction of new information about response functions, photocouplings, and $\eta N$ coupling strengths of baryon resonances. A sharp structure is seen at $W~1.7$ GeV. The shape of the differential cross section is indicative of the presence of a $P$-wave resonance that persists to high $Q^2$. Improved values are derived for the photocoupling amplitude for the $S_{11}$(1535) resonance. The new data greatly expand the $Q^2$ range covered, and an interpretation of all data with a consistent parametrization is provided.

It is assumed that strong chromofields are generated at early stages of ultrarelativistic heavy-ion collisions which give rise to a collective deceleration of baryons from colliding nuclei. We have solved classical equations of motion for baryonic slabs under the action of a time-dependent longitudinal chromoelectric field. It is demonstrated that the slab final rapidities are rather sensitive to the strength and decay time of the chromofield as well as to the back reaction of the produced partonic plasma. The net-baryon rapidity loss $\langle \delta y\rangle =2.0$, found for most central Au-Au collisions at RHIC, can be explained by the action of chromofields with the initial energy density of about 50 GeV/fm${}^3$. Predictions of the baryon stopping for the LHC energy are made.

The threshold electrodisintegration of the deuteron at backward angles is studied in instant form Hamiltonian dynamics, including a relativistic one-pion-exchange potential (OPEP) with off-shell terms as predicted by pseudovector coupling of pions to nucleons. The bound and scattering states are obtained in the center-of-mass frame, and then boosted from it to the Breit frame, where the evaluation of the relevant matrix elements of the electromagnetic current operator is carried out. The latter includes, in addition to one-body, also two-body terms due to pion exchange, as obtained, consistently with the OPEP, in pseudovector pion-nucleon coupling theory. In order to estimate the magnitude of the relativistic effects we perform, for comparison, the calculation with a nonrelativistic phase-equivalent Hamiltonian and consistent one-body and two-body pion-exchange currents. Our results for the electrodisintegration cross section show that, in the calculations using one-body currents, relativistic corrections become significant (i.e., larger than 10%) only at high momentum transfer $Q$ ($Q^2\simeq 40$ fm${}^{-2}$ and beyond). However, the inclusion of two-body currents makes the relativistic predictions considerably smaller than the corresponding nonrelativistic results in the $Q^2$ region (18–40) fm${}^{-2}$. The calculations based on the relativistic model also confirm the inadequacy, already established in a nonrelativistic context, of the present electromagnetic current model to reproduce accurately the experimental data at intermediate values of momentum transfers.

We perform a systematic study of the impact of the ${\mathbf{J}}^2$ tensor term in the Skyrme energy functional on properties of spherical nuclei. In the Skyrme energy functional, the tensor terms originate from both zero-range central and tensor forces. We build a set of 36 parametrizations, covering a wide range of the parameter space of the isoscalar and isovector tensor term coupling constants with a fit protocol very similar to that of the successful SLy parametrizations. We analyze the impact of the tensor terms on a large variety of observables in spherical mean-field calculations, such as the spin-orbit splittings and single-particle spectra of doubly-magic nuclei, the evolution of spin-orbit splittings along chains of semi-magic nuclei, mass residuals of spherical nuclei, and known anomalies of radii. The major findings of our study are as follows: (i) Tensor terms should not be added perturbatively to existing parametrizations; a complete refit of the entire parameter set is imperative. (ii) The free variation of the tensor terms does not lower the ${\chi }^2$ within a standard Skyrme energy functional. (iii) For certain regions of the parameter space of their coupling constants, the tensor terms lead to instabilities of the spherical shell structure, or even to the coexistence of two configurations with different spherical shell structures. (iv) The standard spin-orbit interaction does not scale properly with the principal quantum number, such that single-particle states with one or several nodes have too large spin-orbit splittings, whereas those of nodeless intruder levels are tentatively too small. Tensor terms with realistic coupling constants cannot cure this problem. (v) Positive values of the coupling constants of proton-neutron and like-particle tensor terms allow for a qualitative description of the evolution of spin-orbit splittings in chains of Ca, Ni, and Sn isotopes. (vi) For the same values of the tensor term coupling constants, however, the overall agreement of the single-particle spectra in doubly-magic nuclei is deteriorated, which can be traced back to features of the single-particle spectra that are not related to the tensor terms. We conclude that the currently used central and spin-orbit parts of the Skyrme energy density functional are not flexible enough to allow for the presence of large tensor terms.

We study the matter produced in heavy-ion collisions, assuming that this matter is strongly interacting and employing AdS/CFT correspondence to investigate its dynamics. At late proper times τ we show that Bjorken hydrodynamics solution, obtained recently by Janik and Peschanski using gauge-gravity duality [1], can be singled out by simply requiring that the metric tensor is a real and single-valued function of the coordinates everywhere in the bulk, without imposing any constraints on the curvature invariant. At early proper times we use a similar strategy to show that the energy density $\epsilon$ approaches a constant as $\tau \to 0$. We therefore demonstrate that the strong coupling dynamics incorporates the isotropization transition in heavy-ion collisions. By matching our early-time regime with the late-time one of Janik and Peschanski we estimate the isotropization time at RHIC to be approximately ${\tau }_{\mathrm{iso}}\approx 0.3$ fm/$c$, in good agreement with results of hydrodynamic simulations.

Production of $D_{\mathit{sJ}}(2317)$ mesons in relativistic heavy ion collisions at the BNL Relativistic Heavy Ion Collider is studied. Using the quark coalescence model, we first determine the initial number of $D_{\mathit{sJ}}(2317)$ mesons produced during hadronization of created quark-gluon plasma. The predicted $D_{\mathit{sJ}}(2317)$ abundance depends sensitively on the quark structure of the $D_{\mathit{sJ}}(2317)$ meson. An order-of-magnitude larger yield is obtained for a conventional two-quark than for an exotic four-quark $D_{\mathit{sJ}}(2317)$ meson. To include the hadronic effect on the $D_{\mathit{sJ}}(2317)$ meson yield requires the absorption cross sections of the $D_{\mathit{sJ}}(2317)$ meson by pions, ρ mesons, anti-kaons, and vector anti-kaons, which we have evaluated in a phenomenological model. Taking into consideration the absorption and production of $D_{\mathit{sJ}}(2317)$ mesons during the hadronic stage of heavy ion collisions via a kinetic model, we find that the final yield of $D_{\mathit{sJ}}(2317)$ mesons remains sensitive to its initial number produced from the quark-gluon plasma, providing thus the possibility of studying the quark structure of the $D_{\mathit{sJ}}(2317)$ meson and its production mechanism in relativistic heavy ion collisions.

We present a convenient analytical parametrization of the deuteron wave function obtained previously within a certain dispersion technique. We fit the numerical results with a discrete superposition of Yukawa-type functions in both configuration and momentum spaces.

A preliminary investigation of $\overline{K}N$ interaction is performed within a chiral constituent quark model by solving the resonating group method (RGM) equation. The model parameters are taken from our previous work, which gave a satisfactory description of the $S$-, $P$-, $D$-, $F$-wave $\mathit{KN}$ scattering phase shifts. The channel-coupling between $\overline{K}N,\pi \Lambda$ and $\pi \Sigma$ is considered, and the scattering phase shifts as well as the bound-state problem of $\overline{K}N$ are dynamically studied. The results show that the $S$-wave $\overline{K}N$ interaction in the isospin $I=0$ channel is attractive, and in the extended chiral SU(3) quark model such an attraction can make for a $\overline{K}N$ bound state, which appears as a $\pi \Sigma$ resonance in the coupled-channel calculation, while the chiral SU(3) quark model cannot accommodate the existence of a $\overline{K}N$ bound state. It seems that the vector meson exchanges are necessary to be introduced in the quark-quark interactions if one tries to explain the $\Lambda (1405)$ as a $\overline{K}N$ bound state or a $\pi \Sigma$-$\overline{K}N$ resonance state.

We study the characteristics of some quantities in the interacting boson model (IBM) that are sensitive to the nuclear shape phase transitions. By analyzing the variational features of the quantities with respect to the increasing of total boson number in the U(5)-SU(3) and U(5)-O(6) transitions, we find that the $B(E2)$ ratios, such as $B(E2;4_1\to 2_1)/B(E2;2_1\to 0_1)$ and $B(E2;0_2\to 2_1)/B(E2;2_1\to 0_1)$, can serve as the effective order parameters to distinguish a first order from a second order nuclear shape phase transition.

We have searched for strangelets in a triggered sample of 61 million central (top 4%) Au+Au collisions at $\sqrt{s_{{}_{\mathit{NN}}}}=200$ GeV near beam rapidities at the STAR solenoidal tracker detector at the BNL Relativistic Heavy Ion Collider. We have sensitivity to metastable strangelets with lifetimes of order $⩾0.1$ ns, in contrast to limits over ten times longer in BNL Alternating Gradient Synchrotron (AGS) studies and longer still at the CERN Super Proton Synchrotron (SPS). Upper limits of a few ${10}^{-6}$ to ${10}^{-7}$ per central Au+Au collision are set for strangelets with mass $\gtrsim 30$ GeV/$c^2$.

We present the expansion of the two-pion exchange three-nucleon potential (TPE-3NP) to chiral order $q^4$, which corresponds to a subset of all possibilities at this order and is based on the $\pi N$ amplitude at $\mathcal{O}(q^3)$. Results encompass both numerical corrections to strength coefficients of previous $\mathcal{O}(q^3)$ terms and new structures in the profile functions. The former are typically smaller than 10% whereas the latter arise from either loop functions or nonlocal gradients acting on the wave function. The influence of the new TPE-3NP over static and scattering three-body observables has been assessed and found to be small, as expected from perturbative corrections.

The x-ray cascade from antiprotonic atoms was studied for ${}^{208}\mathrm{Pb}$ and ${}^{209}\mathrm{Bi}$. Widths and shifts of the levels due to the strong interaction were determined. Using modern antiproton-nucleus optical potentials, the neutron densities in the nuclear periphery were deduced. Assuming two-parameter Fermi distributions (2pF) describing the proton and neutron densities, the neutron rms radii were deduced for both nuclei. The difference of neutron and proton rms radii $\Delta r_{\mathit{np}}$ equal to $0.16\pm (0.02){}_{\mathrm{stat}}\pm (0.04){}_{\mathrm{syst}}$ fm for ${}^{208}\mathrm{Pb}$ and $0.14\pm (0.04){}_{\mathrm{stat}}\pm (0.04){}_{\mathrm{syst}}$ fm for ${}^{209}\mathrm{Bi}$ were determined, and the assigned systematic errors are discussed. The $\Delta r_{\mathit{np}}$ values and the deduced shapes of the neutron distributions are compared with mean field model calculations.

A microscopic description of the quasielastic ($p,n$) charge-exchange reaction (here, charge-exchange scattering between analog states) is presented and discussed. Emphasis is focused on the spin-isospin structure of the projectile-target coupling. The model is a coupled-channel extension of the full-folding optical model approach (OMP) developed for nucleon elastic scattering, where emphasis is placed on retaining the genuine off-shell behavior of realistic effective interactions in the nuclear medium. The resulting non-local optical potentials are applied to the calculation of ($p,n$) differential cross sections, with particular emphasis on small-angle Fermi ($\Delta S=0$) cross sections to isobaric analog states. These parameter-free results provide a reasonable description of the ${}^{14}\mathrm{C}$($p,n$) data at proton energies above ∼100 MeV, but deteriorate for heavier targets. These shortcomings are analyzed and possible ways to correct them are discussed.

In nova outbursts on oxygen-neon white dwarfs, the ${}^{30}\mathrm{P}$($p,\gamma$)${}^{31}\mathrm{S}$ reaction plays a crucial role in the synthesis of heavier nuclear species, from Si to Ca. However, this important rate is very uncertain as a result of the lack of spectroscopic information on most of the levels above the proton threshold in ${}^{31}\mathrm{S}$. To reduce these uncertainties, we have measured differential cross sections for the ${}^{32}\mathrm{S}$($p,d$)${}^{31}\mathrm{S}$ reaction and determined excitation energies for states in ${}^{31}\mathrm{S}$. A total of 26 states in ${}^{31}\mathrm{S}$ were observed, including 17 above the proton threshold. Five new states were observed. Spins and parities were determined or constrained for 15 of the observed levels through a distorted wave Born approximation analysis of the angular distributions, of which six were made for the first time. We have evaluated 66 levels using existing data in combination with this measurement and calculated a new ${}^{30}\mathrm{P}$($p,\gamma$)${}^{31}\mathrm{S}$ reaction rate. We confirmed the spin-parity assignment of ${1/2}^{+}$ for the state at 6263 keV which dominates the ${}^{30}\mathrm{P}$($p,\gamma$)${}^{31}\mathrm{S}$ reaction rate at lower temperatures in novae, while the state at 6544 keV dominates at temperatures above 0.2 GK. Our results indicate that the ${}^{30}\mathrm{P}$($p,\gamma$)${}^{31}\mathrm{S}$ rate is reduced by up to a factor of 10 at nova temperatures compared to previous estimates.

The prospects for the synthesis of transactinide nuclei using radioactive beams are evaluated quantitatively for a modern radioactive beam facility. A simple formalism for calculating the complete fusion cross sections that reproduces the known heavy element production cross sections over six orders of magnitude is used to calculate the production rates for transactinide nuclei with $Z⩽120$. All possible projectile and target combinations are evaluated. Exciting new possibilities for studies of the atomic physics, chemistry, and nuclear spectroscopy of the heaviest elements should be realized at a modern radioactive beam facility. The synthesis of new heavy elements is best undertaken at stable beam accelerators.

By examining the structure in momentum and coordinate space of a two-body interaction spherically symmetric in its local coordinate, we demonstrate that it can be disentangled into two distinctive contributions. One of them is a medium-independent and momentum-conserving term, whereas the other is functionally—and exclusively—proportional to the radial derivative of the reduced matrix element. As an example, this exact result was applied to the unabridged optical potential in momentum space, leading to an explicit separation between the medium-free and medium-dependent contributions. The latter does not depend on the strength of the reduced effective interaction but only on its variations with respect to the density. The modulation of radial derivatives of the density enhances the effect in the surface and suppresses it in the saturated volume. The generality of this result may prove to be useful for the study of surface-sensitive phenomena.