We calculate the evolution of the coupled electron-phonon system in a metal film subjected to an electric field. The detailed form of the phonon distribution is presented, and is shown to deviate significantly from a Bose distribution.

We have measured 9-GHz ultrasonic attenuation in GdAl${\mathrm{O}}_3$ in a high magnetic field. The experimental data for $H$ perpendicular to the easy axis of magnetization in the vicinity of the exchange transition point give evidence for resonant interaction between spin waves and ultrasonic waves in the canted phase, and anharmonic processes in the canted and paramagnetic phases.

Subbarrier fission resonances have been found in ${}_{}{}^{230,232}{}_{}{}^{}\mathrm{Th}(t, pf)$ and ${}_{}{}^{230}{}_{}{}^{}\mathrm{Th}(d, pf)$ reactions. This is in disagreement with the fission barriers predicted by the Strutinskĭ theory.

We have measured the cross sections for excitation of the ground-state rotational band in ${}_{}{}^{152}{}_{}{}^{}\mathrm{Sm}$ by high-energy electrons. The ground-state charge distribution has been determined including the deformation parameters ${\beta }_2$ and ${\beta }_4$ of the nuclear surface.

Differential cross sections have been measured for the reaction ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$(${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$)${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ leading to the first three states of ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ at c.m. energies from 17.5 to 30 MeV and c.m. angles of approximately 62°, 76°, and 90°. The yield curves are characterized by (1) gross structures and narrow structures, and (2) strong angular and cross correlations. It is suggested that these results present direct evidence for shape or quasimolecular resonances in the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$+ ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ system.

We present evidence for the interaction of high-spin two-quasiproton bands with two-quasineutron bands in ${}_{}{}^{176}{}_{}{}^{}\mathrm{Hf}$. The two $K^{\pi }=6^{+}$ bands at 1333.1 and 1761.5 keV are shown to be of highly mixed character. A $K^{\pi }=8^{-}$ band at 1559.4 keV, which is largely of two-proton character, is shown to be mixed with a predominantly two-neutron $K=8^{-}$ band at 1860.3 keV.

In the framework of the distorted-wave Born approximation, a generator-coordinate formalism is used for optical waves. This results in a microscopic prescription for the calculation of transfer reaction form factors. A preliminary analysis of the reaction ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$(${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$)${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$ gives a reasonable fit to the angular distribution.

The previously known levels of ${}_{}{}^{39}{}_{}{}^{}\mathrm{K}$ at 3.94 and 4.52 MeV have been shown to be doublets. Two of these levels are candidates for the missing low-lying negative-parity states predicted by shell-model and phonon-hole calculations.

The excitation energy dependence of the competition between neutron emission and fission has been calculated for nuclei in the vicinity of the ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ closed shell. A two-center model has been used to calculate single-particle effects on the nuclear level density as well as on the barrier heights. Comparison with experiment demonstrates the importance of including the dependence of the single-particle level density on deformation.

${}_{}{}^4{}_{}{}^{}\mathrm{He}(\gamma , p){}_{}{}^3{}_{}{}^{}\mathrm{H}$ and ${}_{}{}^4{}_{}{}^{}\mathrm{He}(\gamma , n){}_{}{}^3{}_{}{}^{}\mathrm{He}$ cross sections have been calculated for photon energies from the ($\gamma , n$) threshold to 34 MeV. Effects of Coulomb interactions, channel spin mixing, and mass differences have been taken into account using a coupled-channel continuum-shell-model calculation of $p$-${}_{}{}^3{}_{}{}^{}\mathrm{H}$ and $n$-${}_{}{}^3{}_{}{}^{}\mathrm{He}$ elastic and charge-exchange scattering. The ratio $\frac{\sigma (\gamma , p)}{\sigma (\gamma , n)}$ is predicted to be close to 1, except at energies very close to the ($\gamma , n$) threshold.

We have measured, by the missing-mass technique, spectra of the neutral-meson system $X^0$ produced in ${\pi }^{-}p\to {\pi }^{-}p{X}^0$ at 13.4 GeV/c. The ${\pi }^0$, ${\rho }^0$, and ${\omega }^0$ appear as well as a broad enhancement at 450 MeV and a narrow peak at 1280 MeV which is interpreted as the $D^0$. Most of the ${\pi }^0$ signal and the events around 450 MeV are correlated with $N^{*+}$ production. The ${\rho }^0$ peak results primarily from ${A_1}^{-}-{A_2}^{-}$ decays. We find, however, that the ${\omega }^0$ and $D^0$ are largely uncorrelated with $N^{*+}$ or $X^{-}$ resonances.

The fermion-loop model introduced by Steinberger to explain the decay ${\pi }^0\to \gamma \gamma$ is suitably modified for weak interactions so that it provides a qualitative explanation for ${K_2}^0\to \gamma \gamma$ as well. The weak Hamiltonian is phenomenologically constructed from the one-baryon octet matrix elements of the symmetric quark model. Since these parameters are fitted to the nonleptonic decay of hyperons, this is a model for ${K_2}^0\to \gamma \gamma$ with no adjustable parameters.

Strong confirmatory evidence is found for the existence of a $D_{13}$ resonant state around 1670 MeV c.m. energy; and evidence, though somewhat weaker, is obtained for the existence of a stray baryonic $F_{15}$ state recently conjectured by Donnachie.

A motional electric-field quenching technique has been employed to measure the Lamb shift ($\mathcal{S}$) in the $n=2\mathrm{}$ state of ${\mathrm{O}}^{7+}$. The result is $\mathcal{S}=2202.7\mathrm{}\pm 11.0$ GHz, in agreement with the recent quantum-electrodynamic calculation of $\mathcal{S}=2205.17\mathrm{}\pm 1.56$ GHz.

The energy difference between the $2S_{\frac{1}{2}}$ and $2P_{\frac{1}{2}}$ levels in the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}_{}^{7+}{}_{}{}^{}$ ion has been determined by means of a Stark-quenching technique to be 2215.6 ± 7.5 GHz.

We have observed metastable autoionizing states associated with partially stripped, highly excited chlorine ions. Charge-state-fraction, electron-energetic, and series-limit arguments indicate that these states are primarily associated with sodiumlike chlorine (${\mathrm{Cl}}^{6+}$), but few energy-level calculations exist for firm identification. Prominent peaks occur in the electron spectrum at 90±3, 101±3, 138±3, and 182±3 eV. A long-lived component of the 182-eV peak has a lifetime ≥ 43 nsec.

The higher-order $\Delta m=3\mathrm{}$ and $\Delta m=4\mathrm{}$ transitions in MgO: ${\mathrm{Fe}}^{2+}$ (effective spin = 1) have been observed directly by acoustic paramagnetic resonance. The angular dependence and temperature dependence are found to differ significantly from the normally "allowed" $\Delta m=1\mathrm{}$ and $\Delta m=2\mathrm{}$ transitions. A theory due to Fedders and Myles agrees well with the observed behavior of the $\Delta m=4\mathrm{}$ line.

A theory for acoustic magnetic resonance of paramagnetic ions in a dielectric at frequencies $\omega =m{\omega }_0$ is proposed, where $\hslash {\omega }_0$ is the splitting between adjacent energy levels of the paramagnetic ions and $m=3, 4$, or some larger integer.

We calculate the angular and spectral distribution of atoms evaporating from superfluid helium using a kinetic-theory description of the liquid quasiparticles. Phase-space analysis indicates that the evaporation spectrum exhibits information about the single-particle properties of the liquid, but in particular does not manifest the quasiparticle density of states. The latter conclusion is in agreement with recent experimental results.

Three-dimensional plasma numerical simulation on cross-field diffusion has been performed for cases with closed and nonclosed field lines of force. For the former case, the diffusion essentially takes the form found for two dimensions showing the three regions of diffusion, while for the latter, the diffusion follows the classical theory to stronger fields. However, the diffusion is always enhanced above the classical level when the magnetic field exceeds a critical value.