The analysis method proposed in V. Rotival and T. Duguet [Phys. Rev. C 79, 054308 (2009)] is applied to characterize halo properties in finite many-fermion systems. First, the versatility of the method is highlighted by applying it to light- and medium-mass nuclei as well as to atom-positron and ion-positronium complexes. Second, the dependence of nuclear halo properties on the characteristics of the energy-density functional used in self-consistent Hartree-Fock-Bogoliubov calculations is studied. We focus in particular on the influence of (i) the scheme used to regularize/renormalize the ultraviolet divergence of the local pairing functional, (ii) the angular-momentum cutoff in the single-particle basis, as well as (iii) the isoscalar effective mass, (iv) saturation density, and (v) tensor terms characterizing the particle-hole part of the energy functional. It is found that (a) the low-density behavior of the pairing functional and the regularization/renormalization scheme must be chosen coherently and with care to provide meaningful predictions, (b) the impact of pairing correlations on halo properties is significant and is the result of two competing effects, (c) the detailed characteristics of the pairing functional has, however, only little importance, and (d) halo properties depend significantly on any ingredient of the energy-density functional that influences the location of single-particle levels; i.e., the effective mass, the tensor terms, and the saturation density of nuclear matter. The latter dependencies give insights to how experimental data on medium-mass drip-line nuclei can be used in the distant future to constrain some characteristics of the nuclear energy-density functional. Last but not least, large-scale predictions of halos among all spherical even-even nuclei are performed using specific sets of particle-hole and particle-particle energy functionals. It is shown that halos in the ground state of medium-mass nuclei will be found only at the very limit of neutron stability and for a limited number of elements.

The $g$ factors and mean lifetimes of several short-lived low-lying states in ${}_{30}^{70}$${\mathrm{Zn}}_{40}$ have been measured using the techniques of projectile Coulomb excitation in inverse kinematics combined with transient magnetic fields and the Doppler-shift attenuation method. The present results have been interpreted within the framework of large-scale shell-model calculations that include the $g_{9/2}$ orbital.

The relativistic diffusion process of heavy quarks is formulated on the basis of the relativistic Langevin equation in Itô discretization scheme. The drag force inside the quark-gluon plasma (QGP) is parametrized according to the formula for the strongly coupled plasma obtained by the anti-de-Sitter space/conformal field theory (AdS/CFT) correspondence. The diffusion dynamics of charm and bottom quarks in QGP is described by combining the Langevin simulation under the background matter described by the relativistic hydrodynamics. Theoretical calculations of the nuclear modification factor $R_{\mathrm{AA}}$ and the elliptic flow $v_2$ for the single electrons from the charm and bottom decays are compared with the experimental data from the relativistic heavy-ion collisions. The $R_{\mathrm{AA}}$ for electrons with large transverse momentum ($p_T>3$ GeV) indicates that the drag force from the QGP is as strong as the AdS/CFT prediction.

We have implemented the Tsallis statistics in a Blast-Wave model (TBW) and applied it to midrapidity transverse-momentum spectra of identified particles measured at BNL Relativistic Heavy Ion Collider (RHIC). This new TBW function fits the RHIC data very well for $p_T<3$ GeV/$c$. We observed that the collective flow velocity starts from zero in $p+p$ and peripheral $\mathrm{Au}+\mathrm{Au}$ collisions and grows to $0.470\pm 0.009c$ in central $\mathrm{Au}+\mathrm{Au}$ collisions. The resulting $(q-1)$ parameter, which characterizes the degree of nonequilibrium in a system, indicates an evolution from a highly nonequilibrated system in $p+p$ collisions toward an almost thermalized system in central $\mathrm{Au}+\mathrm{Au}$ collisions. The temperature and collective velocity are well described by a quadratic dependence on $(q-1)$. Two sets of parameters in our TBW are required to describe the meson and baryon groups separately in $p+p$ collisions while one set appears to fit all spectra in central $\mathrm{Au}+\mathrm{Au}$ collisions.

The “island of the inversion” isotope ${}^{31}\mathrm{Mg}$ was investigated using an intermediate energy proton knockout reaction from ${}^{32}\mathrm{Al}$ at 90 MeV/nucleon at the National Superconducting Cyclotron Laboratory. A negligible cross section to the ground state supports an intruder-dominant configuration in ${}^{31}\mathrm{Mg}$. The partial cross sections to excited final states preferentially populate configurations in the ${}^{31}\mathrm{Mg}$ residues which have no neutron excitations across the $N=20$ shell closure. There is strong evidence that the reaction populates the $3/2^{+}$ and $5/2^{+}$ states which correspond with the neutron-hole states predicted by the shell model with the model space truncated above the $\mathit{sd}$-shell.

Inelastic neutron scattering and reactions on Pb isotopes can result in $\gamma$ rays near the signature end-point energy in a number of $\beta \beta$ isotopes. In particular, there are $\gamma$-ray transitions in ${}^{206,207,208}\mathrm{Pb}$ that might produce energy deposits at the ${}^{76}\mathrm{Ge}{Q}_{\beta \beta }$ in Ge detectors used for $0\nu \beta \beta$ searches. The levels that produce these $\gamma$ rays can be excited by ($n,n^{\text{'}}\gamma$) or ($n,\mathit{xn}\gamma$) reactions, but the cross sections are small and previously unmeasured. This work uses the pulsed neutron beam at the Los Alamos Neutron Science Center to directly measure reactions of interest to $\beta \beta$-decay experiments. The cross section on ${}^{\mathrm{nat}}\mathrm{Pb}$ to produce the 2041-keV $\gamma$ ray from ${}^{206}\mathrm{Pb}$ is measured to be 3.6 ± 0.7 (stat.) ± 0.3 (syst.) mb at $\approx 9$.6 MeV. The cross section on ${}^{\mathrm{nat}}\mathrm{Pb}$ to produce the 3061,3062-keV $\gamma$ rays from ${}^{207}\mathrm{Pb}$ and ${}^{208}\mathrm{Pb}$ is measured to be 3.9 ± 0.8 (stat.) ± 0.4 (syst.) mb at the same energy. We report cross sections or place upper limits on the cross sections for exciting some other levels in Pb that have transition energies corresponding to $Q_{\beta \beta }$ in other $\beta \beta$ isotopes.

Results from long-term measurements of a chemically separated Db/Rf sample prepared from the products of a ${}^{48}\mathrm{Ca}$ on ${}^{243}\mathrm{Am}$ irradiation are presented. The sample with the highest spontaneous fission activity out of eight samples produced in the course of chemical experiments performed in 2004 was selected for these measurements. We conclude that there is no evidence for SF-decay originating from heavy actinide isotopes in this sample. Hence, it is appropriate to assign the SF-events observed in this experiment to decay products of ${}^{288}115$.

By projecting the stochastic mean-field dynamics on a suitable collective path during the entrance channel of heavy-ion collisions, expressions for transport coefficients associated with relative distance are extracted. These transport coefficients, which have forms similar to those familiar from the nucleon exchange model, are evaluated by carrying out time-dependent Hartree-Fock simulations. The calculations provide an accurate description of the magnitude and form factor of transport coefficients associated with one-body dissipation and fluctuation mechanisms.

Fission fragment mass distributions have been measured from the decay of the compound nucleus ${}^{246}\mathrm{Bk}$ that has been populated via two entrance channels. These entrance channels have a slight difference in their mass asymmetries that puts them on either side of the Businaro Gallone mass asymmetry parameter. Both target nuclei were deformed. Near the Coulomb barrier, at similar excitation energies, the width of the fission fragment mass distribution was found to be drastically different for the ${}^{14}\mathrm{N}+{}^{232}\mathrm{Th}$ reaction compared to the ${}^{11}\mathrm{B}+{}^{235}\mathrm{U}$ reaction. The entrance channel mass asymmetry was found to affect the fusion process sharply.

The computation of hard processes in hadronic collisions is a major success of perturbative quantum chromodynamics (pQCD). In such processes, pQCD not only predicts the hard reaction itself, but also the subsequent evolution in terms of parton branching and radiation, leading to a parton shower and ultimately to an observable jet of hadrons. If the hard process occurs in a heavy-ion collision, a large part of this evolution takes place in the soft medium created along with the hard reaction. An observation of jets in heavy-ion collision thus allows a study of medium-modified QCD shower evolution. In vacuum, Monte Carlo (MC) simulations are well established tools to describe such showers. For jet studies in heavy-ion collisions, MC models for in-medium showers are currently being developed. However, the shower-medium interaction depends on the nature of the microscopic degrees of freedom of the medium created in a heavy-ion collision which is the very object one would like to investigate. This paper presents a study in comparison between three different possible implementations for the shower-medium interaction, two of them based on medium-induced pQCD radiation, one of them a medium-induced drag force, and shows for which observables differences between the three scenarios become visible. We find that while single hadron observables such as $R_{\mathit{AA}}$ are incapable of differentiating between the scenarios, jet observables such as the longitudinal momentum spectrum of hadrons in the jet show the potential to do so.

We explore quark-hadron duality in semi-inclusive pion electroproduction on proton and neutron targets. Using the spin-flavor symmetric quark model, we compute ratios of ${\pi }^{+}$ and ${\pi }^{-}$ cross sections for both unpolarized and polarized scattering and discuss realizations of duality in several symmetry-breaking scenarios. The model calculations allow one to understand some of the key features of recent data on semi-inclusive pion production at low energies.

The Δ-isobar degrees of freedom are taken into account in neutron star matter and their contributions to neutrino mean free paths are evaluated. It is found that the charged-current contributions are comparable to those from the neutral-current reactions. The contributions of Δ-isobars may be a leading sector of neutrino opacities in neutron star matter, but the effects of the process in which the baryon transforms between nucleon and Δ are unimportant.

We report on an updated Paris $N\overline{N}$ optical potential. The long- and intermediate-range real parts are obtained by $G$-parity transformation of the Paris $\mathit{NN}$ potential based on a theoretical dispersion-relation treatment of the correlated and uncorrelated two-pion exchange. The short-range imaginary potential parametrization results from the calculation of the $N\overline{N}$ annihilation box diagram into two mesons with a nucleon-antinucleon intermediate state in the crossed channel. The parametrized real and imaginary short range parts are determined by fitting not only the existing experimental data included in the 1999 version of the Paris $N\overline{N}$ potential, but also the recent antiprotonic-hydrogen data and $\overline{n}p$ total cross sections. The description of these new observables is improved. Only this readjusted potential generates an isospin zero ${}^1{S}_0$, 52 MeV broad quasibound state at 4.8 MeV below the threshold. Recent BES data on $J/\psi$ decays could support the existence of such a state.

Two-neutron correlation in the ${}^{1}S$ channel in quasi-two-dimensional (2D) neutron systems at zero temperature is studied by means of the BCS theory with finite-range effective nuclear forces. The dineutron correlation in low density neutron systems confined in an infinite slab is investigated in a simplified model that neutron motion of one direction is frozen. When the slab is thin enough, two neutrons form a tightly bound dineutron with a small size in the quasi-2D system, and a Bose dineutron gas is found in low density limit. With increase of Fermi momentum, the neutron system changes from the Bose-gas phase to the superfluid Cooper pair phase. The density dependence of the neutron pairing shows the BCS-BEC crossover phenomena at finite low-density region. In the transition region, the size shrinking of neutron pair and enhancement of pairing gap are found. The relation to dineutron correlation at surface of neutron-rich nuclei is also discussed.

Three-body calculations of $(d,p)$ and $(p,d)$ reactions involving one-neutron halo nuclei ${}^{11}\mathrm{Be}$ and ${}^{15}\mathrm{C}$ are performed using the framework of Faddeev-type scattering equations. Important effects of the optical potential nonlocality are found improving the description of the experimental data. The obtained values for the neutron spectroscopic factor are consistent with estimations from other approaches.

We have studied the centrality bin size dependence of charged particle forward-backward multiplicity correlation strength in 5%, 0–5%, and 0–10% most central $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{s_{\mathit{NN}}}=200$ GeV with a parton and hadron cascade model, PACIAE based on PYTHIA. The real (total), statistical, and negative binomial distribution (NBD) correlation strengths are calculated by the real events, the mixed events, and fitting the charged particle multiplicity distribution to the NBD, respectively. It turned out that the correlation strength increases with increasing centrality bin size monotonously. If the discrepancy between real (total) and statistical correlation strengths is identified as dynamical one, the dynamical correlation may just be a few percent of the total (real) correlation.

We investigate the multiplicity fluctuations observed in high-energy nuclear collisions attributing them to intrinsic fluctuations of temperature of the hadronizing system formed in such processes. To account for these fluctuations, we replace the usual Boltzmann-Gibbs (BG) statistics by the nonextensive Tsallis statistics characterized by the nonextensivity parameter $q$, with $|q-1|$ being a direct measure of fluctuation. In the limit of vanishing fluctuations, $q\to 1$ and Tsallis statistics converge to the usual BG. We evaluate the nonextensivity parameter $q$ and its dependence on the hadronizing system size from the experimentally observed collision centrality dependence of the mean multiplicity $\langle N\rangle$ and its variance Var$(N)$. We attribute the observed system size dependence of $q$ to the finiteness of the hadronizing source, with $q=1$ corresponding to an infinite, thermalized source with a fixed temperature, and with $q>1$ (which is observed) corresponding to a finite source in which both the temperature and energy fluctuate.

The elliptic flow excitation function calculated in a full ($3+1$) dimensional hybrid Boltzmann approach with an intermediate hydrodynamic stage for heavy ion reactions from GSI Schwerionen Synchrotron to the highest CERN Super Proton Synchrotron (SPS) energies is discussed in the context of the experimental data. In this study, we employ a hadron gas equation of state to investigate the differences in the dynamics and viscosity effects. The specific event-by-event setup with initial conditions and freeze-out from a nonequilibrium transport model allows for a direct comparison between ideal fluid dynamics and transport simulations. At higher SPS energies, where the pure transport calculation cannot account for the high elliptic flow values, the smaller mean free path in the hydrodynamic evolution leads to higher elliptic flow values. In contrast to previous studies within pure hydrodynamics, the more realistic initial conditions employed here and the inclusion of a sequential final state hadronic decoupling provides results that are in line with the experimental data almost over the whole energy range from $E_{\mathrm{lab}}=2\text{−}160A$ GeV. Thus, this new approach leads to a substantially different shape of the $v_2/\epsilon$ scaling curve as a function of $(1/S{\mathit{dN}}_{\mathrm{ch}}/\mathit{dy})$ in line with the experimental data compared to previous ideal hydrodynamic calculations. This hints at a strong influence of the initial conditions for the hydrodynamic evolution on the finally observed $v_2$ values, thus questioning the standard interpretation that the hydrodynamic limit is only reached at BNL Relativistic Heavy Ion Collider energies.

We propose a novel statistical approach to the analysis of experimental data obtained in nucleus-nucleus collisions at high energies which borrows from methods developed within the context of random matrix theory. It is applied to the detection of correlations in a system of secondary particles. We find good agreement between the results obtained in this way and a standard analysis based on the method of effective mass spectra and two-pair correlation function often used in high energy physics. The method introduced here is free from unwanted background contributions.

Developments and applications are presented of an algebraic version of Bohr's collective model. Illustrative examples show that fully converged calculations can be performed quickly and easily for a large range of Hamiltonians. As a result, the Bohr model becomes an effective tool in the analysis of experimental data. The examples are chosen both to confirm the reliability of the algebraic collective model and to show the diversity of results that can be obtained by its use. The focus of the paper is to facilitate identification of the limitations of the Bohr model with a view to developing more realistic, computationally tractable models.