The intranuclear cascade-evaporation model of a high-energy nucleon-meson transport code has been used to calculate neutron production from nonelastic interactions of 585 MeV protons with C, Al, Fe, Nb, In, Ta, Pb, and U targets at emission angles of 30°, 90°, and 150°. These model predictions are compared with measurements of the double differential cross sections $d^2$σ/dΩ${\mathrm{dT}}_{\mathrm{n}}$ of neutrons with kinetic energies between 0.9 and 585 MeV. In general, the model predicts approximately the correct neutron production in the evaporation region, whereas in the high energy region ($E_{\mathrm{n}\mathrm{\gtrsim }20}$ MeV) systematic discrepancies between measurements and model predictions occur. These increase rapidly with increasing neutron energy and increasing emission angle.

Missing mass spectra from ${}_{}{}^3{}_{}{}^{}\mathrm{He}$(p,d)X at $T_{\mathrm{p}=0.75\mathrm{}}$ GeV (${\theta }_{\mathrm{lab}=22\mathrm{}}$°, 32°, and 40°) and $T_{\mathrm{p}=0.925\mathrm{}}$ GeV (${\theta }_{\mathrm{lab}=30\mathrm{}}$° and 40°) have been measured. Missing mass spectra from p${(}^3$He,d)X at $T_{{\mathrm{}}^3\mathrm{He}=2.7\mathrm{}}$ GeV and ${\theta }_{\mathrm{lab}=18\mathrm{}}$° have also been measured. The experiments have been carried out with a high missing mass resolution in order to detect possible narrow structures associated with B=2, T=1 quantum numbers. Such structures have been seen, with the following masses and widths: $M_x$=2.240±0.005, (${\Gamma }_{1/2}$≊0.016±0.003) GeV, $M_x$=2.192±0.003, (${\Gamma }_{1/2}$≊0.025±0.006) GeV, and $M_x$=2.121±0.003, (${\Gamma }_{1/2}$≊0.025±0.002) GeV. A broad structure with mass close to $M_x$≊2.17 GeV, the mass of free N+Δ, and a width close to ${\Gamma }_{1/2}$≊0.1 GeV is observed. The observed peaks might be related to six-quark states.

Measurements of the tensor and vector spin observables C(0,NN,0,0), C(0,SS,0,0), and C(0,N,0,0), in p-d elastic scattering at 600, 800, and 1000 MeV equivalent proton bombarding energy, are reported. The data were taken in the range 0.1<-t<1.2 (GeV/c${)}^2$. The experiment employed a polarized deuteron beam with tensor and vector components of ±0.75 and ±0.25, respectively, a liquid hydrogen target, and a single arm magnetic spectrometer. The tensor and vector spin parameters C(0,N,0,0) and C(0,NN,0,0) were extracted from the data with beam polarization normal to the scattering plane. The observable C(0,SS,0,0) was obtained by precessing the deuteron polarization into the scattering plane. Comparison of the data with the predictions of a relativistic multiple scattering theory is made.

A model is proposed for studying tunneling in many-particle systems that is simple enough to solve and realistic enough to test various collective models of multidimensional barrier penetration. We find that the imaginary time dependent mean-field theory works very well in its domain of applicability, as does a continuum hopping approximation. The usual cranked mean field approximation is much less reliable.

The first Green’s function Monte Carlo calculations of A=3 and 4 nuclei with spin-dependent interactions are reported. Green’s function Monte Carlo methods for calculating the properties of coupled channel quantum systems are described in detail, including both exact and approximate schemes. Results are presented for A=3 and 4 nuclei with a V6 interaction. For the triton, the Green’s function Monte Carlo calculations are compared with Faddeev and variational methods. Green’s function Monte Carlo calculations of the alpha particle provide the first test of variational methods for systems with spin-dependent interactions. For this interaction, variational methods underestimate the binding energy of the alpha particle by ≊2 MeV. Other ground state properties of light nuclei have also been determined. Implications of these results for more realistic interactions are discussed, along with the possibility of future extensions of Green’s function Monte Carlo methods to treat momentum dependent and three nucleon interactions.

We demonstrate that the energy eigenvalues of the low energy octupole modes of nuclei in the Z=12–20, N=12–20 region follow a simple pattern which can be observed in a graph of E${(3\mathrm{}}_1^{\mathrm{-}}$) versus $N_{\mathrm{p}+N_{\mathrm{n}}}$, where $N_{\mathrm{p}}$ ($N_{\mathrm{n})}$ is the valence number of protons (neutrons) in the s-d shell. This pattern is discussed in terms of a parametrization for these states which has previously been applied to several regions of spherical and transitional nuclei between atomic masses 60 and 220.

We have investigated a sensitivity of short range behavior of the nucleon-nucleon tensor interaction on the ${}_{}{}^3{}_{}{}^{}\mathrm{S}_1^{}{}_{}{}^{}$${\mathrm{-}}^3$${\mathrm{D}}_1$ mixing parameter and the triton binding energy. It is found that, by varying the short range behavior of a tensor component to repulsive from attractive, we can get an additional triton binding energy of about 0.7 MeV. At the same time, the mixing parameter becomes too small to be acceptable. For a proposed potential to be really ‘‘realistic,’’ the mixing parameter should carefully be fitted to experimental values.

Model wave functions are constructed for the deuteron to facilitate the unambiguous exploration of dependencies on the percentage D state and on the small-, medium-, and large-distance parts of the deuteron wave function. The wave functions are constrained by those deuteron properties which are accurately known experimentally, and are in an analytic form which is easily integrable in expressions usually encountered in the use of such wave functions.

A model of nuclear matter is given in which nonrelativistic quarks, carrying color, moving in one dimension, interact through a contact interaction. Solutions for the ground-state energy as a function of density may be found exactly using a method based on the Bethe ansatz, which is explained in detail. The model system shows characteristic behavior of a Fermi gas of nucleons (bound clusters of quarks) at low density, and of a Fermi gas of free quarks at high density, with a smooth transition between these limits.

A comparison is made of the rotational model and the large shell model for the calculation of the magnetic dipole excitations in selected nuclei in the s-d and f-p shells. Focus is given on both the relatively low lying strong states and higher ‘‘spin flip’’ excitations. It is found that the two models agree fairly well for summed B(M1) strength, but for the deformations that were used give different results for orbital and spin decomposition. The rotational model yields too much low lying strength as compared with the shell model. A technique for eliminating spurious contributions to the summed strength in the rotational model is developed. It is shown that in the asymptotic limit in some nuclei the magnetic dipole excitations are purely orbital. The implications of these calculations to results in heavier deformed nuclei for ‘‘scissor mode’’ excitations is discussed.

The magnetic multipole even-parity transitions are calculated in ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ti}$ with a mind to finding interesting collective behavior and to study the effects of increasing the model space. The single-j shell signature selection rules are compared to those in the neutron-proton interacting boson model with good F spin. There are similarities but also differences. Some behavior of the single-j shell calculation survives as the model space increases, e.g., low lying collective M1 and M7 modes. Configuration mixing is, however, vital to describe the M3 and M5 modes as well as the spin flip M1 modes. The distribution of strength between lower and higher isospins is discussed. Results are compared with calculated transitions in ${}_{}{}^{42}{}_{}{}^{}\mathrm{Sc}$. It appears that allowing one-particle excitations from the single-j shell gives the pattern of the strength distribution; the further addition of two-particle excitations leads to a quenching of the strength distribution.

Nuclear magnetic resonance of oriented nuclei measurements on ${}_{}{}^{119}{}_{}{}^{}\mathrm{Te}_{}^{\mathrm{m}}{}_{}{}^{}$Fe, ${}_{}{}^{121}{}_{}{}^{}\mathrm{Te}_{}^{\mathrm{m}}{}_{}{}^{}$Fe, and ${}_{}{}^{123}{}_{}{}^{}\mathrm{Te}_{}^{\mathrm{m}}{}_{}{}^{}$Fe have been made at about 7 mK. The resonances were observed in an external magnetic field of 2 kG at ν(${}^{119}$${\mathrm{Te}}^{\mathrm{m}}$Fe)=84.6(1) MHz, ν(${}^{121}$${\mathrm{Te}}^{\mathrm{m}}$Fe)=84.7(5) MHz, and ν(${}^{123}$${\mathrm{Te}}^{\mathrm{m}}$Fe)=87.8(2) MHz. With the known hyperfine field of $B_{\mathrm{HF}}$(TeFe)=681(4) kG, the magnetic moments could be determined as ‖μ(${}^{119}$${\mathrm{Te}}^{\mathrm{m}}$, (11/$2^{\mathrm{-}}$)‖=0.894(6) ${\mu }_{\mathrm{N}}$, ‖μ(${}^{121}$${\mathrm{Te}}^{\mathrm{m}}$, (11/$2^{\mathrm{-}}$)‖=0.895(10) ${\mu }_{\mathrm{N}}$, and ‖μ(${}^{123}$${\mathrm{Te}}^{\mathrm{m}}$, (11/$2^{\mathrm{-}}$)‖=0.927(8) ${\mu }_{\mathrm{N}}$. The measured values of the magnetic moments are compared with the calculated values based on the core polarization model.

Nuclear orientation and nuclear magnetic resonance measurements have been performed for ${}_{}{}^{196}{}_{}{}^{}\mathrm{Au}$ oriented at 6 and 12 mK in an iron host. The magnetic hyperfine-splitting frequency ‖g${\mu }_{\mathrm{N}{B}_{\mathrm{HF}/\mathrm{h}\mathrm{\Vert }}}$ and the quadrupole splitting frequency $e^2$qQ/h were determined to be 258.26(10) and -2.22(15) MHz, respectively. With the known hyperfine field of -1147.3(8) kG and electric field gradient of (-)0.113(6)×${10}^{17}$ V/${\mathrm{cm}}^2$, the magnetic moment and the spectroscopic quadrupole moment were deduced to be μ=0.5906(5) ${\mu }_{\mathrm{N}}$ and Q=0.81(7) b, respectively. From angular distributions of γ rays, the deorientation parameters of $U_2$ and $U_4$ for the $2^{\mathrm{-}}$→$2^{+}$ first-forbidden transitions from ${}_{}{}^{196}{}_{}{}^{}\mathrm{Au}$ to ${}_{}{}^{196}{}_{}{}^{}\mathrm{Pt}$ and ${}_{}{}^{196}{}_{}{}^{}\mathrm{Hg}$ have been deduced.

A method is presented by which a geometrical interpretation can be given for boson models without leaving the domain of quantum mechanics. This approach turns out to be particularly useful in symmetry-preserving treatments of deformed boson systems. A U(3) boson model having an SO(2) symmetry, which is to be preserved throughout, is analyzed in detail. For a well-deformed system, rotational and vibrational modes are identified. A procedure is developed by which the parameters of the geometrical description for the deformed case can be calculated in a series expansion controlled by the inverse of the boson number. The method is compared with the corresponding random phase approximation approach.

The g factors of the first $2_1^{+}$ states in ${}_{}{}^{50}{}_{}{}^{}\mathrm{Cr}$ and ${}_{}{}^{54}{}_{}{}^{}\mathrm{Cr}$ have been measured by the perturbed angular correlation/transient field technique. The results, g($2_1^{+}$, ${}_{}{}^{50}{}_{}{}^{}\mathrm{Cr}$)=+0.45(15) and g($2_1^{+}$, ${}_{}{}^{54}{}_{}{}^{}\mathrm{Cr}$)=+0.53(12), are compared to shell model calculations.

The generator coordinate method approach to the dynamic group representation is discussed in general. In various cases, either in group space or in coset space, representations of the dynamic group can readily be obtained with the generator coordinate method. Boson representation is just one form of the generator coordinate method approach to the dynamic group representation. Various representations of the dynamic group are described by the generator coordinate method approach to the dynamic group representation in a unified way. Not only is the algebraic structure of generators preserved, but also conditions imposed by (a) the Pauli principle, (b) symmetry properties, (c) dynamic properties, and (d) other concrete properties of nuclear systems are well incorporated in these representations, so that the original fermion representation is faithfully realized. The generator coordinate method approach to the dynamic group representation is strictly a transformation theory from the fermion representation to continuous variable or boson representations of the dynamic group. Examples are given for showing the essence and the prospects of applications of the generator coordinate method approach to the dynamic group representation.

The coherent-state model is extended to the description of the proton-neutron systems. Three (p,n) symmetric bands (g, β, and γ̃) and three asymmetric bands (γ, $1^{+}$, 1${̃}^{+}$) are simultaneously considered. Their wave functions are obtained through projection from six deformed states which are mutually orthogonal. An effective quadrupole boson Hamiltonian which is diagonal in the projected basis is constructed. Applications to ${}_{}{}^{156}{}_{}{}^{}$,158,160Gd show very good agreement with the experimental data concerning the g, β, and γ bands and the $1^{+}$ isovector state. Predictions for two additional bands, one with K=2(γ̃) and one with K=1(1${̃}^{+}$), are also presented. A detailed analysis for the electromagnetic properties of the $1^{+}$ M1 state is given.

New states in the yrast band of ${}_{}{}^{74}{}_{}{}^{}\mathrm{Se}$ have been seen with the reaction ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$${(}^{28}$Si,α2p${)}^{74}$Se at 98 MeV. The new states extend the known level scheme up to $J^{\pi }$${=(22\mathrm{}}^{+}$). For the states $J^{\pi }$≥$6^{+}$ the spectrum shows a relatively constant moment of inertia parameter ${ħ}^2$/2θ=27.8±0.5 keV.

A natural molybdenum source was used in a time projection chamber to look for five modes of ββ. We place half-life limits of 6.8×${10}^{17}$ yr on ββ(2ν), 1.3×${10}^{19}$ yr on ββ(0ν), and 7.5×${10}^{18}$ yr on ββ(0ν,B) for ${}_{}{}^{100}{}_{}{}^{}\mathrm{Mo}$, and limits of 2.3×${10}^{17}$ yr on ${\beta }^{+}$,EC(2ν) and 2.7×${10}^{18}$ yr on ${\beta }^{+}$,EC(0ν) for ${}_{}{}^{92}{}_{}{}^{}\mathrm{Mo}$.

Excitation functions were measured for the deexcitation by neutron evaporation of the compound nucleus ${}_{}{}^{200}{}_{}{}^{}\mathrm{Po}$ formed in the interactions of ${}_{}{}^{84}{}_{}{}^{}\mathrm{Kr}$${+}^{116}$Cd and ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$${+}^{160}$Dy. In general, the results are consistent with the predictions of the statistical model of nuclear reactions, including effects of angular momentum and deexcitation by fission. However, few neutron (2n,3n) evaporation is more favored in ${}_{}{}^{84}{}_{}{}^{}\mathrm{induced}$ reactions than in those involving ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$, a result that is not predicted by the statistical model.