The vector analyzing power ${\mathit{A}}_{\mathit{y}}$(θ) of the ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(p→,p${)}^2$H scattering has been measured at ${\mathit{E}}_{\mathit{p}}$=5, 6, 6.5, 7, 8, 8.5, 9, 10, 12, 14, 16, and 18 MeV with a typical statistical accuracy of 0.0009 and an uncertainty in the beam polarization of less than 0.7%. The differential cross section σ(θ) of the ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(p,p${)}^2$H scattering has also been measured with a typical uncertainty of 0.8% using unpolarized beams of the same energies and of 2, 2.5, 3, and 4 MeV. A large discrepancy of about 25% between the experiment and the Faddeev calculation with the Paris NN potential is observed at the maximum of ${\mathit{A}}_{\mathit{y}}$(θ) around ${\mathrm{\theta }}_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=120°. This discrepancy is shown to be reduced by modifying LS force in the NN potential, though a discrepancy still remains in the energy dependence of the ${\mathit{A}}_{\mathit{y}}$(θ) maximum. At the minimum of σ(θ) around ${\mathrm{\theta }}_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=120°, a large discrepancy ranging from -19% at 2 MeV to +24% at 18 MeV is observed between the experiment and the calculations with either of the original and the LS-modified NN potentials. This indicates that an improvement is also necessary in the scalar part of the potential. The difference in the ${\mathit{A}}_{\mathit{y}}$(θ) maximum between the p→+d and the n→+d scatterings is discussed.

A measurement of the analyzing power ${\mathit{A}}_{\mathit{y}}$(θ) in neutron-deuteron (n-d) elastic scattering below the deuteron breakup threshold is described, including a detailed discussion of the experimental apparatus and the treatment of systematic errors. The data provide a precise test of Faddeev calculations of the three-nucleon system and of the nucleon-nucleon interaction models used as inputs to these calculations. ${\mathit{A}}_{\mathit{y}}$ was measured at six angles from 44.5 ° c.m. to 145.7 ° c.m. to a precision of (7–13)×${10}^{\mathrm{-}4}$. Polarized neutrons, produced by the ${}_{}{}^3{}_{}{}^{}\mathrm{H}$(p→,n→${)}^3$He reaction, were incident upon the target, a deuterated organic scintillator. Scattered neutrons were detected in fast coincidence with the recoil deuterons in the target. A computer simulation of the experiment was used to compensate for a number of systematic errors. Particularly important were corrections for neutron multiple scattering, accidental coincidences, and finite geometry effects. The ${\mathit{A}}_{\mathit{y}}$ data have a 2.2% scale factor uncertainty associated with uncertainty in the polarization of the incident neutron beam. The incident neutron polarization was measured in a separate experiment using n${\mathrm{-}}^4$He scattering from a liquid helium scintillator. The neutron polarization measurement also yielded an improved value for the polarization transfer coefficient [${\mathit{K}}_{\mathit{y}}^{\mathit{y}}$($0^{\mathrm{°}}$)=0.650±0.019] in the ${}_{}{}^3{}_{}{}^{}\mathrm{H}$(p→,n→${)}^3$He reaction at ${\mathit{E}}_{\mathrm{lab}}^{\mathit{p}}$=3.80 MeV. A comparison of the ${\mathit{A}}_{\mathit{y}}$ data to Faddeev calculations shows that the discrepancy in ${\mathit{A}}_{\mathit{y}}$ observed previously at higher energies continues below the breakup threshold. A comparsion of the ${\mathit{A}}_{\mathit{y}}$ data to a recent phase shift analysis of proton-deuteron (p-d) scattering indicates that observed differences between n-d and p-d analyzing powers are only partially explained by Coulomb effects.

Kinematically complete breakup cross section and proton analyzing power data for four different collinearity configurations (neutron at rest in the c.m. system) have been measured in the reaction ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(p→,pp)n at ${\mathit{E}}_{\mathit{p}}^{\mathrm{lab}}$=65 MeV. The experimental data are compared with rigorous solutions of the Faddeev equations using the Argonne AV14, Bonn B, Nijmegen, and Paris potentials. While the overall agreement is quite good there exist distinct discrepancies between theoretical and experimental cross section and analyzing power data in some regions of phase space.

We study the nucleon-nucleon interaction in the framework of the chromodielectric soliton model (CDM). Here, the long-range parts of the non-Abelian gluon self-interactions are assumed to give rise to a color-dielectric function which is parametrized in terms of an effective scalar background field. The six-quark system is confined in a deformed mean field through an effective nonlinear interaction between the quarks and the scalar field. The CDM is covariant, respects chiral invariance, leads to absolute color confinement, and is free of the spurious long-range van der Waals forces which trouble nonrelativistic investigations employing a confining potential. Six-quark molecular-type configurations are generated as a function of deformation and their energies are evaluated in a coupled channel analysis. By using molecular states instead of cluster model wave functions, all important six-quark configurations are properly taken into account. The corresponding Hamiltonian includes the effective interaction between the quarks and the scalar background field and quark-quark interactions generated through one gluon exchange treated in Coulomb gauge. When evaluating the gluonic propagators, the inhomogeneity and deformation of the dielectric medium are taken into account. Results for the adiabatic nucleon-nucleon potential are presented, and the various contributions are discussed. Finally, an outlook is given on how, in the next stage of our investigation, dynamical effects will be incorporated by employing the generator coordinate method.

A numerical method, based on the Euclidean path integral formulation of quantum mechanics, to evaluate the ground state energy and wave function of a quantum system is discussed. The method is illustrated in one-dimensional cases, and then applied to a two-body system interacting through central and tensor potentials. A detailed discussion of the deuteron problem with a realistic nuclear potential is given.

The utility of (e,e’d) reactions in providing information about dynamical correlations in nuclei is discussed. The breakup of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ into two deuterons is taken as a model case. We show how two-nucleon dynamics of both short range and tensor nature affects the (e,e’d) cross section in different kinematical regions. The role of final state interactions is also discussed. Within our model, kinematical conditions can be chosen to emphasize the sensitivity to a particular aspect of the ground state dynamics thereby suggesting promoting avenues for experiment.

We assume that nucleon-antinucleon annihilation is a fast process leading to a classical coherent pion pulse. We develop the quantum description of such pion waves based on the method of coherent states. We study the consequences of such a description for averages of charge types and moments of distributions of pion momenta with isospin and four-momentum conservation taken into account. We briefly discuss the applicability of our method to annihilation at rest, where we find agreement with experiment, and suggest other avenues for its use.

A recent analysis of exclusive pion production in proton-proton scattering allows for the direct comparison of theory with pp→n${\mathrm{\Delta }}^{++}$ observables. We have extracted NN→NΔ transition amplitudes from the Bonn meson-exchange model and calculated differential cross section and asymmetry for this reaction. In particular, we establish correlations between the asymmetry and the phases of the major inelastic transition amplitudes. We find evidence that the phases of the transition amplitude ${}_{}{}^3{}_{}{}^{}$${\mathit{F}}_3$(NN)${\to }^5$${\mathit{P}}_3$(NΔ) are responsible for the large discrepancy between theory and experiment in the asymmetry around 800 MeV incident laboratory kinetic energy. We also suggest how the theory can be improved.

The magnetic moment and quadrupole moment of the radioactive isotope ${}_{}{}^{143}{}_{}{}^{}\mathrm{Pr}$ have been measured by collinear laser-ion-beam spectroscopy. The magnetic moment is found to be μ(143)=+2.701(4)${\mathrm{\mu }}_{\mathit{N}}$; the quadrupole moment, Q(143)=+0.77(16)eb. The experimental values are discussed by comparing them with the theoretical values of pairing-plus-quadrupole, intermediate-coupling, and interacting-boson-fermion models.

A systematic, high resolution (6–8 keV) study of (d,t) reactions on ${}_{}{}^{100,102,104}{}_{}{}^{}\mathrm{Ru}$ is reported. Spectroscopic factors were extracted by comparison of experimental angular distributions with distorted wave Born approximation predictions. All of the information for ${}_{}{}^{99}{}_{}{}^{}\mathrm{Ru}$ and, for excitation energies above 0.9 MeV, for ${}_{}{}^{103}{}_{}{}^{}\mathrm{Ru}$ is new. Most of the strength expected for the 50–82 neutron shell was found. The strength distributions are discussed, also in comparison with the corresponding stripping reactions. Special attention is focused on extremely low and relatively intense l=3 excitations and on the l=4 transfer pattern observed.

Mean lifetimes of bound states in ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ were inferred from the Doppler-shift-attenuation (DSA) of γ rays produced in the inverse reaction ${}_{}{}^2{}_{}{}^{}\mathrm{H}$${(}^{14}$N,pγ) and from the primary gamma-ray-induced Doppler broadening (GRID) of secondary γ rays in the thermal-neutron capture reaction ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$(n,γ). Targets for the DSA measurements were prepared by implanting first neon into a gold backing and then deuterium into the same region such that deuterium was trapped at the neon precipitates. To find out experimentally the initial velocity distributions of the recoiling ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ nuclei, another target was prepared by implanting deuterium into silicon, which is a slow stopping-power medium. Computer simulations with the Monte Carlo method and experimental stopping powers were used in the DSA analysis of the γ-ray line shapes. This analysis yielded the following lifetimes for eight bound levels in ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$: 43±4 fs (5.30 MeV), <12 fs (6.32 MeV), 11±2 fs (7.16 MeV), <3 fs (7.30 MeV), 129±6 fs (7.57 MeV), <3 fs (8.31 MeV), <10 fs (8.57 MeV), and <4 fs (9.05 MeV). GRID measurements were made with melamine (${\mathrm{C}}_3$${\mathrm{H}}_6$${\mathrm{N}}_6$) and with silicon nitride (${\mathrm{Si}}_3$${\mathrm{N}}_4$) as both targets and slowing-down media. Measurements were also made with air (80% nitrogen). The Doppler-broadened γ-ray line shapes were analyzed by molecular-dynamics simulations of the slowing-down process to obtain the lifetime values of 40±3 fs (5.30 MeV), <2 fs (6.32 MeV), <3 fs (7.30 MeV), and <3 fs (8.31 MeV) for levels in ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$. The extent to which the mirror symmetry of levels in ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ and ${}_{}{}^{15}{}_{}{}^{}\mathrm{O}$ is valid is examined in some detail.

States in the neutron-deficient ${}_{}{}^{110,112}{}_{}{}^{}\mathrm{Te}$ isotopes have been populated following ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$${+}^{58,60}$Ni reactions. Gamma-ray coincidence data were acquired with the Eurogam spectrometer in conjunction with the Daresbury recoil separator and with the Chalk River 8π spectrometer. Although the low lying yrast states are not collective in these nuclei, a long regular cascade of transitions, indicating collective behavior, was found in ${}_{}{}^{112}{}_{}{}^{}\mathrm{Te}$ extending to high spin. This structure is interpreted in terms of a deformed 4-particle 2-hole $0_2^{+}$ state coupled to rotationally aligned quasiparticles, and represents the first example of a rotational ‘‘intruder’’ band in the tellurium isotopes.

The nuclei ${}_{}{}^{132,134}{}_{}{}^{}\mathrm{Pr}$ have been investigated using the ${}_{}{}^{100}{}_{}{}^{}\mathrm{Mo}$${(}^{37}$Cl,xn) reactions at a beam energy of 155 MeV. Gamma rays were detected with the Eurogam array. Analysis of the data has revealed the presence of two new weakly populated decoupled bands in ${}_{}{}^{134}{}_{}{}^{}\mathrm{Pr}$. One of these bands has been linked into the normal-deformed states and is thought to be built on a π(${\mathit{h}}_{11/2}$${)}^2$⊗ν(${\mathit{f}}_{7/2}$,${\mathit{h}}_{9/2}$) configuration. The second band has been interpreted as being based on a π(${\mathit{h}}_{11/2}$${)}^3$⊗ν${\mathit{i}}_{13/2}$ intruder configuration within the second ${\mathrm{\beta }}_2$≃0.3 prolate minimum. The known decoupled band in ${}_{}{}^{132}{}_{}{}^{}\mathrm{Pr}$ (5n reaction channel) and the highly deformed band in ${}_{}{}^{130}{}_{}{}^{}\mathrm{La}$ A(α3n) have also been extended. The structure of all of these bands is discussed together with similar bands in nieghboring odd-odd nuclei.

High-spin states up to (29/$2^{+}$) and (29/$2^{\mathrm{-}}$) in ${}_{}{}^{71}{}_{}{}^{}\mathrm{As}$ have been studied via the ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$${(}^{19}$F,α2p) reaction at 62 MeV using in-beam γ-ray spectroscopic techniques. Based on a particle-γ coincidence measurement a new decay sequence of negative parity has been assigned to ${}_{}{}^{71}{}_{}{}^{}\mathrm{As}$. Lifetimes for some E2 transitions were extracted from Doppler-shifted line shapes observed in coincidence mode, and experimental transition quadrupole moments were determined. They indicate a moderate to high collectivity in both the positive-parity yrast band and the new negative-parity decay sequence at high spins. Total Routhian surfaces calculated for states of both parities reveal strong triaxial shapes at high spins. A noncollective structure of 19/$2^{\left(\mathrm{-}\right)}$ and 21/$2^{\left(\mathrm{-}\right)}$ states is interpreted as a three-quasiparticle excitation.

The positron decay partial half-lives of ${}_{}{}^{143}{}_{}{}^{}\mathrm{Pm}$ and ${}_{}{}^{144}{}_{}{}^{}\mathrm{Pm}$ are needed to assess the viability of elemental Pm as a cosmic-ray clock. We have conducted experiments to measure the ${\mathrm{\beta }}^{+}$ branches of these isotopes; we find ${\mathrm{\beta }}^{+}$ branches of <5.7×${10}^{\mathrm{-}6}$% for ${}_{}{}^{143}{}_{}{}^{}\mathrm{Pm}$ and <8×${10}^{\mathrm{-}5}$% for ${}_{}{}^{144}{}_{}{}^{}\mathrm{Pm}$. Although these branches are a factor of 20 lower than the previous experimental limits, the resulting partial half-lives are still too uncertain to permit any firm conclusions.

Directional correlations of coincident gamma transitions in ${}_{}{}^{72}{}_{}{}^{}\mathrm{Ge}$ have been measured following the ${\mathrm{\beta }}^{\mathrm{-}}$ decay of ${}_{}{}^{72}{}_{}{}^{}\mathrm{Ga}$ (${\mathit{T}}_{1/2}$=14.1 h), using a spectrometer consisting of a Ge(Li) and a Ge detector. The measurements were carried out for 16 gamma cascades populated in ${}_{}{}^{72}{}_{}{}^{}\mathrm{Ge}$, three of which measured for the first time. The results permitted definite spin assignments to the levels at 3325 keV ($3^{\mathrm{-}}$) and 3342 keV ($2^{\mathrm{-}}$). In addition, several previous spin assignments to other levels in ${}_{}{}^{72}{}_{}{}^{}\mathrm{Ge}$ were confirmed. The multipole mixing ratios for 14 γ-ray transitions were determined from the present results.

Six new rotational bands have been established in ${}_{}{}^{115}{}_{}{}^{}\mathrm{I}$ at high spin using the near symmetric ${}_{}{}^{60}{}_{}{}^{}\mathrm{Ni}$${(}^{58}$Ni,3pγ) reaction at 250 MeV. Several of the bands are observed to frequencies beyond ħω=1.0 MeV (spin approaching 50ħ). All the bands show a characteristic drop off in their dynamic moments of inertia with increasing spin. The low values at the highest spins are consistent with predictions for a band termination in which a gradual shape change from collective prolate to noncollective oblate occurs over many transitions. these smoothly occurring terminations contrast with the abrupt ‘‘favored’’ terminations previously observed in this and other odd-A iodine nuclei.

A phenomenological analysis of the experimental odd-even differences in the moments of inertia, δJ/J, of well-deformed rare-earth nuclei is reviewed, which reveals that there exist large fluctuations in δJ/J with the blocked levels in odd-A nuclei. A calculation using the particle-number conserving treatment shows that the odd-even difference in the moments of inertia is a pure quantum mechanical interference effect and the experimental strong fluctuations in δJ/J with the blocked level can be reproduced satisfactorily. The calculated value of δJ/J depends sensitively on the energetic location and Coriolis response of the blocked level and the underlying physics is discussed. Particularly, δJ/J is especially large if the blocked orbital is a high-j intruder orbital near the Fermi surface. In contrast, if the blocked orbital is of normal parity with low j and high Ω (e.g., proton [404] 7/2, [402]5/2), δJ/J almost vanishes.

We propose a general form of hybrid derivative coupling model of scalar mesons to various baryons in a field theoretical model to study nuclear matter. The strength of Yukawa point coupling and that of derivative coupling of scalar mesons to various baryons are taken in a suitable proportion characterized by a hybridization parameter α. Analytical relations are set up which express scalar and vector meson coupling constants, compression modulus and the parameter α in terms of empirical values for effective nucleon mass, energy per nucleon, and baryon density of normal nuclear matter. Density expansions of effective nucleon mass and energy per nucleon, incorporating terms up to eighth power in nuclear matter density, are given. We study equation of states of dense nuclear matter at zero temperature considering Δ resonances. We also investigate the phase transition from highly compressed nuclear matter to quark matter and its dependence on hybridization parameter α and also on coupling constants involving mesons and Δ’s. We determine equilibrium pressure, chemical potential, ‘‘phase transition density,’’ baryon densities, and energy densities of hadronic matter and quark matter which characterize the phase transition region. We also briefly discuss linear response of the nuclear system in the present model.