We explore neutrino capture during $r$-process nucleosynthesis in neutrino-driven ejecta from nascent neutron stars. We focus on the interplay between charged-current weak interactions and element synthesis, and we delineate the important role of equilibrium nuclear dynamics. During the period of coexistence of free nucleons and light and/or heavy nuclei, electron neutrino capture inhibits the $r$-process. At all stages, capture on free neutrons has a larger impact than capture on nuclei. However, neutrino capture on heavy nuclei by itself, if it is very strong, is also detrimental to the $r$-process until large nuclear equilibrium clusters break down and the classical neutron-capture phase of the $r$-process begins. The sensitivity of the $r$-process to neutrino irradiation means that neutrino-capture effects can strongly constrain the $r$-process site, neutrino physics, or both. These results apply also to $r$-process scenarios other than the neutrino-heated winds.

We investigate the energy dependence of the astrophysical S factor for the reaction ${}^7\mathrm{Be}(p,\gamma {)}^8\mathrm{B}$, the primary source of high-energy solar neutrinos in the solar $\mathrm{pp}$ chain. Using simple models we explore the model dependence in the extrapolation of the experimental data to the region of astrophysical interest near 20 keV. We find that below approximately 400 keV the energy dependence is very well understood and constrained by the data for the elastic scattering of low-energy neutrons from ${}^7\mathrm{Li}$. Above 400 keV nuclear distortion of the wave function of the incident proton introduces a significant model dependence. This is particularly important for the s-wave contribution to the S factor. The extracted value of $S\left(0\right)\mathrm{}$ is $19.0\pm 1.0\pm 0.2$ eV b. The first error is experimental while the second is an estimate of the theoretical error in the extrapolation.

We present a measurement of the induced proton polarization $P_n$ in ${\pi }^0$ electroproduction on the proton around the $\Delta$ resonance. The measurement was made at a central invariant mass and a squared four-momentum transfer of $W=1231\mathrm{}\hspace{0.5em}\mathrm{MeV}$ and $Q^2=0.126\mathrm{}\hspace{0.5em}{\mathrm{GeV}}^2{/c}^2,$ respectively. We measured a large induced polarization, $P_n=-0.397\pm 0.055\pm \mathrm{0.009.}$ The data suggest that the scalar background is larger than expected from a recent effective Hamiltonian model.

Lifetimes of low-lying levels in the $\Delta I=2\mathrm{}$ band built on the $\pi h_{11/2}$ state in the Z-odd nucleus ${}^{135}\mathrm{Pr}$ were measured with the Doppler-shift recoil-distance technique. Reduced transition probabilities B(E2) were extracted in order to calculate the deformation parameters. These values were compared to theoretical results of the total Routhian surface (TRS) calculations. While the quadrupole moments obtained for the $\pi h_{11/2}$ excited levels below the first backbend in ${}^{135}\mathrm{Pr}$ are very similar to those of the ${}^{134}\mathrm{Ce}$ core, TRS results predict a quadrupole moment of about 50$\%$ larger for the core.

Relative intensities of γ rays and conversion electron lines in the decay of ${}^{125}\mathrm{Sb}$ are measured precisely using an HPGe detector and a miniorange electron spectrometer. These data are used to derive the K- and L-shell internal conversion coefficients and to deduce the multipolarities of the respective transitions. A revised level scheme is presented for ${}^{125}\mathrm{Te}$ incorporating 37 transitions between 13 energy levels up to an excitation energy of 675 keV. The newly established levels at 538 and 653 keV complete the hextuplet corresponding to the ${(s}_{1/2}\otimes 2^{+})$ and ${(d}_{3/2}\otimes 2^{+})$ phonon-coupled configurations.

States in ${}^{191}\mathrm{Os}$ have been observed with the ${}^{192}\mathrm{Os}(p,pn\gamma )$ reaction. The most intense $\gamma$ ray observed is the decay from the head of a previously assigned oblate decoupled band. Gamma rays in coincidence with this transition reveal a band structure up to spin ${19/2}^{+}.$ These results, together with those from a previous single-nucleon transfer study, are better reproduced in calculations assuming $\epsilon =0.17\mathrm{}$ and $\gamma =24\mathrm{}°,$ rather than $\epsilon =0.37\mathrm{}$ and $\gamma =43\mathrm{}°$ as previously suggested. Candidates for members of the ground state band are also suggested.

High spin states in the nucleus ${}^{107}\mathrm{In}$ have been investigated using the reaction ${}^{66}\mathrm{Zn}{(}^{45}\mathrm{Sc},2p2n)$ at a beam energy of 162 MeV. Levels up to a spin $\frac{33}{2}ħ$ and an excitation energy 7 MeV have been established from γ-γ coincidence measurements. Two $\Delta I=1\mathrm{}$ sequences have been observed, in addition to a large number of other states arising from single particle excitations. The configuration $\pi g_{9/2}^{-1}\otimes \nu h_{11/2}$ coupled to neutrons in the $d_{5/2}$ and $g_{7/2}$ orbitals appears to have a dominant contribution to the observed negative parity states.

Experimental measurements of the spin transfer observables ${(D}_{\mathrm{ss}},$ $D_{\mathrm{sl}},$ $D_{\mathrm{ll}},$ and $D_{\mathrm{ls}})$ for ${p-}^4\mathrm{He}$ elastic scattering at 800 MeV are reported. The spin rotation parameters Q and S are also deduced from the spin transfer observables. Measurements were made in the angular range of $6°<{\theta }_{\mathrm{lab}}<32\mathrm{}°$ using the Los Alamos Meson Physics Facility (LAMPF). These data are tested against theoretical predictions based on the relativistic and nonrelativistic multiple scattering models which use the results of the phase shift analysis of nucleon-nucleon scattering data. Recent calculations by Auger and Lazard which include the influence of Δ propagation in the intermediate stages of the multiple scattering process and phase dependence of the nucleon-nucleon amplitudes as a function of momentum transfer show better agreement with our experimental data than calculations based on the relativistic impulse approximation.

We present a model study of the quasirotational properties of a system consisting of two angular momentum vectors (blades) interacting via an effective force of the form $V_2{P}_2\left(\theta \right),$ where $\theta$ is the angle between the blades. We find the relationship between angular momentum and rotational frequency and derive from it the kinematical and dynamical moments of inertia. The dynamics of this simple system seems to account for the salient features of the shears bands.

We propose the quark mean field model for nucleons in nuclei, where the meson mean fields created by other nucleons act on quarks in a nucleon and change the nucleon properties in nuclei. We take the constituent quark model for the nucleon, which naturally allows the direct coupling of pions and in turn other mesons as $\sigma$ and $\omega$ mesons. We find very good nuclear matter properties with the use of the nonlinear self-energy terms in the meson Lagrangian. We expect the spin-orbit splitting in finite nuclei to be large due to the large reduction of the nucleon mass, which is in agreement with experiment. The nucleon size increases by about 7% at the normal matter density.

The coupling scheme of the ${}^{16}{\mathrm{O}+}^{208}\mathrm{Pb}$ system has been examined to understand the role of couplings to pickup and transfer channels. The couplings to proton, triton, and α pickup have no consequence for the coupled reaction channel (CRC) results for this system. In general, the couplings to $2n$ pickup or transfer may be important, as these are likely to effect fusion more significantly. A model study indicates that the contribution to total CRC cross section alone is not a criterion to exclude a channel from coupling scheme.

We discuss multiboson symmetrization effects on the normalization and shape of the two-pion correlation function, comparing two different popular definitions of the latter. Explicit algorithms for constructing absolutely normalized correlators from experiment are given.

It is argued that the recently measured $2_1^{+}$ state of the $N=28\mathrm{}$ isotope ${}^{44}\mathrm{S}$ is more collective than that of the $N=20\mathrm{}$ isotope ${}^{36}\mathrm{S}$ because of well-known shifts in the relative energies of the $d_{3/2}$ and $s_{1/2}$ proton orbits between $N=20\mathrm{}$ and 28 and not because of the weakening or collapse of the $N=28\mathrm{}$ shell closure in the neutron-rich region. It is proposed that a Coulomb excitation measurement of the $2_1^{+}$ state in ${}^{42}\mathrm{Si}$ would provide the best determination of whether the $N=28\mathrm{}$ shell closure persists in this neutron-rich region.

We consider production of dilepton pairs through coherent electromagnetic radiation during nuclear collisions. We show that the number of pairs produced through bremsstrahlung is about two orders of magnitude smaller than the yield measured by the CERES Collaboration. Therefore, coherent bremsstrahlung can be ruled out as an explanation for the observed enhancement of low mass dileptons in CERES and HELIOS data.

Extremely inhomogeneous states in the rapidity space of multiparticle production processes are studied using an analytic continuation based on complex-temperature singularities in thermodynamics of multifractals. Good agreement between this approach and results of laboratory experiments on hadron and nuclear collisions at high energies is established.

In-beam γ-ray and γ-γ coincidence measurements have been made for the very neutron-deficient nucleus ${}^{176}\mathrm{Hg}$ using the recoil-decay tagging (RDT) technique. The irregular yrast sequence observed up to $I=10\mathrm{}ħ$ indicates that the prolate intruder band, seen in heavier Hg isotopes near the neutron midshell, crosses the nearly spherical ground-state band of ${}^{176}\mathrm{Hg}$ above $I=6\mathrm{}ħ.$

Gamma rays in the $N=Z+1\mathrm{}$ nucleus ${}^{79}\mathrm{Y}$ were identified using the reaction ${}^{28}\mathrm{Si}{(}^{54}\mathrm{Fe},{p2n)}^{79}\mathrm{Y}$ at a 200 MeV beam energy and an experimental setup consisting of an array of Ge detectors and the Recoil Mass Spectrometer at Oak Ridge National Laboratory. With the help of additional γ-γ coincidence data obtained with Gammasphere, these γ rays were found to form a strongly coupled rotational band with rigid-rotor-like behavior. Results of conventional Nilsson-Strutinsky cranked shell model calculations, which predict a deformation of ${\beta }_2\sim 0.4,$ are in excellent agreement with the properties of this band. Similar calculations for the neighboring $N=Z$ and $N=Z+1\mathrm{}$ nuclei are also in good agreement with experimental data. This suggests that the presence of the putative $T=0\mathrm{}$ neutron-proton pairing does not significantly affect such simple observables as the moments of inertia of these bands at low spins.

Gamma rays decaying from the excited states of the proton-unbound ${}^{151}\mathrm{Lu}$ were observed for the first time in an experiment using the ${}^{96}\mathrm{Ru}{(}^{58}\mathrm{Ni},{p2n)}^{151}\mathrm{Lu}$ reaction. These γ rays were identified by correlating prompt γ radiations at the target position with ${}^{151}\mathrm{Lu}$ proton radioactivities at the focal plane of a recoil mass separator. Systematic data on $N=80\mathrm{}$ isotones suggest a possible isomeric level at high spin in ${}^{151}\mathrm{Lu}.$ Our measurement was unable to observe such an isomer, but provided an upper limit on its half-life. The observed γ rays in ${}^{151}\mathrm{Lu}$ can be interpreted in terms of two possible level structures.

The baryon-number-two $\mathrm{}(B=2\mathrm{})\mathrm{}$ solution based on the SU(2) chiral quark soliton model (χQSM) is solved numerically, including fully the sea quark degrees of freedom. We confirm that the axially symmetric meson configurations yield the energy minimum for the $B=2\mathrm{}$ state in the χQSM when taking into account quark dynamics. Due to the axially symmetric meson fields, six valence quarks occupy the lowest energy level, consistent with the Pauli exclusion principle. The minimal-energy of the entire system is obtained within the framework of a symmetric ansatz. The fermion determinant with axially symmetric meson fields is calculated by diagonalizing the corresponding Dirac Hamiltonian in a nonperturbative way, using a cylindrical Dirac basis. The baryon number density, calculated with quark fields corresponding to a soliton, is toroidal in shape. We also calculate the mean radius of the toroid from the quark fields. These results are closely related to Skyrme model calculations based upon pion degrees of freedom. Our model calculations clarify the underlying dynamical structure of the baryons at the quark level.