We calculate the ground-state properties of well deformed, even-even $N=Z$ nuclei in the region between ${}^{56}\mathrm{Ni}$ and ${}^{100}\mathrm{Sn}$ within two different approaches, focusing on the binding energy and deformation and pairing properties. First, we employ the Hartree-Fock-BCS (HFBCS) approximation with the Skyrme effective nucleon-nucleon interaction and discuss how the results depend on the parametrization of the interaction and on the pairing force parameters adjusted in various schemes to reproduce the experimental odd-even mass differences. Then, within the Higher Tamm-Dancoff Approximation (HTDA), which explicitly conserves the particle number, we calculate the same properties starting from the HFBCS solutions. The HTDA treatment of the ground-state correlations is converged within a $n$-particle-$n$-hole expansion using up to $n=4$ particle-hole excitations of the pair type (in the sense of Cooper pairs). We compare the ground-state properties calculated in these two descriptions of pairing correlations and deduce the importance of the particle-number conservation in weak pairing regimes. Finally, we extend the HTDA calculations so as to include the proton-neutron residual interaction and investigate the role of proton-neutron pairing on the above ground-state properties.

Particle production in the forward region of heavy-ion collisions is shown to be due to parton recombination without shower partons. The regeneration of soft partons due to momentum degradation through the nuclear medium is considered. The degree of degradation is determined by fitting the $\overline{p}/p$ ratio. The data at $\sqrt{s}=62.4$ GeV and $\eta =3.2$ from the BRAHMS Collaboration on the $p_T$ distribution of average charged particles are well reproduced. A large proton-to-pion ratio is predicted. The particles produced at any $p_T$ should have no associated particles above background to manifest any jet structure.

Three different rotational bands have been observed to high spin in ${}^{75}\mathrm{Rb}$ using Gammasphere. The structures are similar, but not identical to those found in the neighboring $T_z=1/2$ nucleus ${}^{73}\mathrm{Kr}$. Conventional total Routhian surface (TRS) calculations with $T=1$ pairing are able to reproduce the rotational bands in ${}^{75}\mathrm{Rb}$ with extreme accuracy, but they completely fail in reproducing the spectra and decay pattern of the negative parity bands in ${}^{73}\mathrm{Kr}$. Simple qualitative arguments are put forward to show that the decay pattern observed in the negative parity bands in ${}^{73}\mathrm{Kr}$ can be accounted for by means of $T=0$ pair correlations. To further corroborate this scenario, deformation, and pairing self-consistent TRS calculations, including schematic $T=1$ and $T=0$ pairing, are performed for the first time indicating the onset of dynamical $T=0$ pair-correlations at high angular momenta.

We study the ground-state shell correction energy of a fermionic gas in a mean-field approximation. Considering the particular case of three-dimensional harmonic trapping potentials, we show the rich variety of different behaviors (erratic, regular, supershells) that appear when the number-theoretic properties of the frequency ratios are varied. For self-bound systems, where the shape of the trapping potential is determined by energy minimization, we obtain accurate analytic formulas for the deformation and the shell correction energy as a function of the particle number $N$. Special attention is devoted to the average of the shell correction energy. We explain why in self-bound systems it is a decreasing (and negative) function of $N$.

The ${}^{203}\mathrm{Tl}$($n,2n\gamma$) reaction was used to study excited states in ${}^{202}\mathrm{Tl}$. The data were taken using the GEANIE spectrometer. The pulsed neutron source of the Los Alamos Neutron Science Center's WNR facility provided neutrons in the energy range from 0.6 to 250 MeV. The time-of-flight technique was used to determine the incident neutron energies. γ-ray excitation functions were measured from the beam-on data, whereas half-lives of isomers were determined from the beam-off data. The level scheme of ${}^{202}\mathrm{Tl}$ has been considerably enriched and the low-spin part of the level scheme exhibits striking similarities to that of the neighboring ${}^{204}\mathrm{Tl}$ isotope. The previously reported first excited state in ${}^{202}\mathrm{Tl}$ has been decomposed into two close-lying states in the present measurement. The half-life of the $7^{+}$ isomer at 950-keV excitation energy was measured with a more precise result that differs by ∼4% from the value adopted in the literature.

We investigate the relation between time-dependent Hartree-Fock (TDHF) states and the adiabatic eigenstates by constructing a boost-invariant single-particle Hamiltonian. The method is numerically realized within a full three-dimensional TDHF which includes all the terms of the Skyrme energy functional and without any symmetry restrictions. The study of free translational motion of a nucleus demonstrates the validity of the concept of boost-invariant and adiabatic TDHF states. The interpretation is further corroborated by the test case of fusion of ${}^{16}\mathrm{O}+{}^{16}\mathrm{O}$. As a first application, we present a study of the nuclear Landau-Zener effect on a collision of ${}^4\mathrm{He}+{}^{16}\mathrm{O}$.

As widely known, the Walecka many-body field theory plays an important role in nuclear physics. This paper investigates such a theory in the context of quantum nonextensive statistical mechanics, characterized by a dimensionless parameter $q$. To this end, we consider nuclear matter described statistically by a power-law distribution which generalizes the standard Fermi-Dirac distribution ($q=1$). We show that the scalar and vector meson fields become more intense because of the nonextensive effects ($q\ne 1$). From a numerical treatment, we also show that as the nonextensive parameter $q$ increases, the nucleon effective mass diminishes and the equation of state becomes stiffer. Finally, the usual Maxwell construction seems not to be necessary for isotherms with temperatures in the range $14<k_{B}T<20$ MeV.

Using the ${}^{40}\mathrm{Ca}$(${}^3\mathrm{He}$,$p$) reaction at ${\text{E}}_{{}^3\mathrm{He}}=9$ MeV and the multidetector array HORUS, angular correlations of coincident pairs of γ transitions in the odd-odd $N=Z$ nucleus ${}^{42}\mathrm{Sc}$ have been measured at the FN tandem Van de Graaff accelerator of the University of Cologne. The analysis of the data allowed nine new spin assignments and the determination of a series of new multipole mixing ratios. In particular, the spin and parity of the $5^{+}$ and $7^{+}$ levels belonging to the lowest $T=0\pi f_{7/2}\nu f_{7/2}$ multiplet have been determined and the ($6^{+}$) level from the $T=1$ multiplet has been tentatively assigned. In this way, all $T=1$ states up to an excitation energy of 3.2 MeV now have known spins as well as the lowest $T=0$ quadruplet ($J^{\pi }=1^{+},3^{+},5^{+},7^{+}$) and many other $T=0$ states of unknown structure. The comparison with shell-model calculations reveals that a breaking of the ${}^{40}\mathrm{Ca}$ core has to be invoked to describe the level structure of ${}^{42}\mathrm{Sc}$.

The astrophysical reaction rate of the ${}^{45}\mathrm{V}$($p,\gamma$)${}^{46}\mathrm{Cr}$ reaction, which is relevant to ${}^{44}\mathrm{Ti}$ production in core-collapse supernovae, has been revised through a consistent application of the Thomas-Ehrman level displacement formalism. The new rate agrees well with that predicted by the NON-SMOKER statistical calculation with an ETFSI mass model.

In the present paper, we examine past measurements of ground state to ground state ($d,p$) and ($p,d$) transfers that were performed on targets with $Z=3–24$. We describe a procedure that we utilized to extract a consistent set of spectroscopic factors. Most of the 80 spectroscopic factors that we extracted are in good agreement with large-basis shell model predictions. We evaluate the consistency of this method by comparing the spectroscopic factors obtained separately in ($p,d$) and ($d,p$) reactions. For nuclei for which Endt has compiled values, our results and those of Endt are strongly correlated. We apply our method to more reactions and more nuclei than Endt had, and our comparisons between spectroscopic factors obtained in ($d,p$) and ($p,d$) reactions display more consistency than the corresponding comparisons in Endt.

X(5) and analytic quadrupole and octupole axially symmmetric (AQOA) models are applied to the ${}^{148}\mathrm{Nd}$ nucleus. In spite of large differences in energy levels between the experiment and the theory, $E$2 matrix elements are described to some extent by the X(5) model for the g band, β band, and γ band. For the octupole band, the AQOA model with tunneling effect can reproduce both energy levels and $E$1, $E$2, and $E$3 matrix elements quite well.

The superscaling analysis is extended to include quasielastic (QE) scattering via the weak neutral current (NC) of neutrinos and antineutrinos from nuclei. The scaling function obtained within the coherent density fluctuation model (CDFM) [used previously in calculations of QE inclusive electron and charge-changing (CC) neutrino scattering] is applied to neutral current neutrino and antineutrino scattering with energies of 1 GeV from ${}^{12}\mathrm{C}$ with a proton and neutron knockout ($u$-channel inclusive processes). The results are compared with those obtained using the scaling function from the relativistic Fermi gas model and the scaling function as determined from the superscaling analysis (SuSA) of QE electron scattering.

The α decay of ${}^{159}\mathrm{Re}$ has been observed for the first time in reactions of 300 MeV ${}^{58}\mathrm{Ni}$ ions with an isotopically enriched ${}^{106}\mathrm{Cd}$ target. The ${}^{159}\mathrm{Re}$ ions were separated in-flight using the RITU separator and implanted into the GREAT spectrometer. The α decay emanates from the proton-emitting $\pi h_{11/2}$ state in ${}^{159}\mathrm{Re}$ with an energy of $E_{\alpha }=6776\pm 26$ keV and a branching ratio of 7.5 ± 3.5%. This α decay populates a state in the closed neutron shell nucleus ${}^{155}\mathrm{Ta}$, which decays by emitting 1444 ± 15 keV protons with a half-life of $2.9_{-1.1}^{+1.5}$ ms. These values are consistent with the emission of the proton from a $\pi h_{11/2}$ orbital. These results fit in with the systematics of proton and α-particle separation energies in the region, but disagree with the previously reported decay properties of ${}^{155}\mathrm{Ta}$.

The multiple scattering of high-energy particles in a thick target is formulated in an impact parameter representation. A formalism similar but not identical to that of Molière is obtained. We show that calculations of particle beam broadening due to multiple Coulomb scattering alone can be given in closed form. The focus of this study is on determining whether the broadening of the Coulomb angular distribution prevents the retrieval of nuclear-interaction information from the measurement of the angular distributions of charged particles scattered from a thick target. For this purpose, we study multiple scattering with both the nuclear and Coulomb interactions included, and we do not make a small-angle expansion. Conditions for retrieving nuclear information from high-energy protons propagating through a block of material are obtained.

We perform calculations for ω production in nuclei by means of the $(\gamma ,p)$ reaction for photon energies and proton angles suited to currently running and future experiments in present laboratories. For some cases of possible ω optical potentials, we find that clear peaks are observable when a good resolution in the ω energy is available. We also study the inclusive production of ${\pi }^0\gamma$ in nuclei around the ω energy and find a double hump structure for the energy spectra, with a peak around a ${\pi }^0\gamma$ energy of $m_{\omega }-100$ MeV, which could easily be misidentified by a signal of an $\omega$ bound state in nuclei, while it is actually due to a different scaling of the uncorrelated ${\pi }^0\gamma$ production and ω production with subsequent ${\pi }^0\gamma$ decay.

We analyze the effect of neutron superfluidity on the cooling time of inner crust matter in neutron stars, in the case of a rapid cooling of the core. The specific heat of the inner crust, which determines the thermal response of the crust, is calculated in the framework of HFB approach at finite temperature. The calculations are performed with two paring forces chosen to simulate the pairing properties of uniform neutron matter corresponding to the BCS approximation and to many-body techniques including polarization effects. Using a simple model for the heat transport across the inner crust, it is shown that the two pairing scenarios mentioned above give very different values for the cooling time, i.e., of about 12 and 25 yr.

We investigate colorless (mesonic) $3q\text{−}q\overline{q}$ components in the nucleon and the Roper resonance $N^{*}(1440)$. Starting from constituent quarks and gluons we estimate the excitation of $q\overline{q}$ pairs in a gluon exchange model with the strong coupling constant extracted from a comparison with a nonperturbative resonating group calculation of the $\pi ,\eta ,\rho$, and ω content of the nucleon. Applying the same model to the Roper resonance, we find as the most striking result a very strong scalar-isoscalar σ-content of the $N^{*}(1440)$ with a strength of the $3q\text{−}q\overline{q}$ configurations comparable to the $3q$ component itself.

In conditions of $4\pi$-geometry, the production of ${\Delta }^0$ and ${\Delta }^{++}$ resonances in collisions of ${}^4\mathrm{He}$ nuclei with carbon nuclei at 4.2 GeV/$c$ per nucleon was investigated for the first time. The masses and widths of resonances were obtained based on an analysis of the experimental and background invariant mass distributions of $p{\pi }^{\pm }$ pairs. The contributions to the pion production from decays of $\Delta$ resonances, as well as from direct pion creation, and the relative number of nucleons excited to ${\Delta }^0$ at freeze-out were estimated. The results obtained were compared to the corresponding data for C+C collisions at the same initial momentum 4.2 GeV/$c$ per nucleon.