A strong dependence of the scattering cross section on molecular orientation was observed when 6.324-MeV photons were scattered from ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ in the form of ${\mathrm{Na}}^{15}$N${\mathrm{O}}_3$ single crystal. This is caused by the different velocities of the N atom corresponding to the various directions of the zero-point molecular vibrations.

A heavy-ion-beam probe has been used to measure the space-potential distribution on the Elmo bumpy torus. The results indicate that under optimum confinement conditions the ambipolar electric field is nearly axisymmetric, points radially inward, and is of sufficient magnitude to dominate the ion poloidal drifts.

In earlier studies of plasma diffusion with Okuda-Dawson scaling ($D\sim n^{-\frac{1}{2}}$), perturbation theory indicated that arbitrary initial data should evolve rapidly toward the separable solution of the relevant nonlinear diffusion equation. Now a Lyapunov functional has been found which is strictly decreasing in time and bounded below. The rigorous proof that arbitrary initial data evolve toward the separable solution is summarized. Rigorous bounds on the decay time are also presented.

We have investigated muon diffusion in niobium with controlled amounts of interstitial impurities. The polarization decay was interpreted in terms of a two-state model where the muon is alternatively in a state of free diffusion or in traps. A good fit of all data was obtained, yielding correlation times for the jump motion, as well as capture and release rates of the traps. The muons are found to be mobile in NB down to 14 K.

We have studied the superfluid transition of a thin two-dimensional helium film adsorbed on an oscillating substrate. The superfluid mass and dissipation when analyzed in terms of the dynamic theory of Ambegaokar, Halperin, Nelson, and Siggia support the Kosterlitz-Thouless picture of the phase transition in a two-dimensional superfluid. The value for the jump in the superfluid density at the transition given by Kosterlitz and Thouless, ${\rho }_s\left({T_c}^{-}\right)=8\mathrm{}\pi k_{\mathrm{B}}{\left(\frac{m}{h}\right)}^2{T}_c$, is in good agreement with estimates from experiment.

Metallic glasses of the alkali metals Rb and Cs containing 13-20 at.% oxygen have been obtained for the first time by rapid cooling (∼ ${10}^2$ K/s) of liquid samples. An investigation of the electronic and structural properties leads to the conclusion that a chemical bonding model is more appropriate for these glasses than a free-electron model. Strongly bonded ionic clusters are responsible for the enhanced tendency for glass formation.

The optical properties of amorphous films of ${\mathrm{Au}}_{1-x}{\mathrm{Si}}_x$ alloys were studied in the spectral range from 0.01 to 6.2 eV as a function of composition in the range $0.13<~x<~0.50$. Because the electronic relaxation times are extremely short, Drude behavior dominates the entire spectrum. The onset energy of interband transitions increases on alloying with Si. In comparison with pure gold a dramatic decrease in strength of the transitions from the $d$ bands to the Fermi surface is observed in all the alloys.

In a magnetic field titled with respect to the sample surface we observe combined resonance transitions because of a coupling of Landau levels and subband states. In the high-density, interacting electron gas on the semiconductor surface these experiments give information on the depolarization and excitonlike shifts involved in the resonant excitation of the system.

A new real-space renormalization method is developed which leads to differential renormalization-group equations. For a two-dimensional triangular Ising lattice these equations can be solved exactly and yield and exact critical properties.

For stationary axially symmetric vacuum metrics, we give a series of transformations ${\beta }^{\mathrm{}\left(k\right)\mathrm{}}$ which automatically preserve asymptotic flatness. We show how to generate the Kerr metric from the Schwarzschild, using ${\beta }^{\mathrm{}\left(0\right)\mathrm{}}$. We also show, using ${\beta }^{\mathrm{}\left(k\right)\mathrm{}}$, that the Tomimatsu-Sata (TS) class of metrices must be larger than previously realized, and for $\delta =2\mathrm{}$ there is a five-parameter TS metric. As an example, we present a two-parameter metric from this family, which we claim to be a new, physically realistic, asymptotically flat, rotating vacuum solution.

The edge of the gap in the distribution of Yang-Lee zeros at $H=i{H}_0\mathrm{}\left(T\right)\mathrm{}$ on the imaginary magnetic field axis in ferromagnets above $T_c$ is essentially a critical point. In terms of the edge exponents $\delta$ and $\eta$, the density of zeros obeys $\mathcal{G}\left(H^{\prime \prime }\right)\sim {[H^{\prime \prime }-H_0\mathrm{}(T\left)\right]}^{\sigma }$, with $\sigma =\frac{1}{\delta }=\frac{(d-2+\eta )}{(d_2-\eta )}$. Classical behavior ($\sigma =\frac{1}{2}$) occurs for $d>\mathrm{}{d}^{\times }=6\mathrm{}$. The appropriate field-theoretic renormalization group entails a $w{\varphi }^3$ coupling and, with $\epsilon =6-d>~0$, yields $\eta \approx -\frac{\epsilon }{9}$ for all $n<\mathrm{}\infty$. This correlates well with refined series estimates for $d=2\mathrm{}$ and $d=3\mathrm{}$ and with exact results for $d=1\mathrm{}$ ($\eta =-1\mathrm{}$).

Cross sections for inclusive electroproduction of ${K_s}^0\text{'}\mathrm{s}$ and $\Lambda \text{'}\mathrm{s}$ have been measured. The ${K_s}^0$ results are combined with data from electron-positron annihilation and charged $K$ electroproduction to give information on quark fragmentation into strange particles. The longitudinal- and transverse-momentum distributions for $\Lambda \text{'}\mathrm{s}$ are compared with those of electroproduced protons.

Yang's parity test for general spin-0 mesons applied to the decay sequence $X=\to \varphi \varphi \to \left(K^{+}{K}^{-}\right)\left(K^{+}{K}^{-}\right)$ leads to maximal parity signature. The correlation function for the azimuthal angle between the two $\varphi \to K^{+}{K}^{-}$ decay planes is given by $1+\beta cos2\varphi$, where $\beta =-1\mathrm{}$ for pseudoscalar $X$, and $1>~\beta >~0$ for scalar $X$.

We outline the proof of a consistent renormalization scheme for the Fermi theory ${\left(\overline{\psi }{\gamma }_{\mu }\frac{1}{2}\tau \psi \right)}^2$ in the context of a mean-field expansion in the collective excitation ${A_i}^{\mu }\equiv \overline{\psi }{\gamma }_{\mu }\frac{1}{2}{{\tau }_i}^{\prime }\psi$. Ward's identities show that there is only one mass and coupling and that the induced vertices are identical to those of Yang-Mills theory with elementary gauge fields at low energy. The Green's-functions equations are displayed and used to derive an eigenvalue restriction on the coupling.

We have measured the electroproduction of hadrons from nuclei and compare it to the electroproduction from deuterium. We find an attenuation of the forward component which increases with $A$. The attenuation is less for lower hadronic momenta, but is not a strong function of the other electroproduction variables.

A correlation experiment between inelastically scattered ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ particles at 1.2° and decay $\alpha$ particles was performed in the giant-resonance region of ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ at an incident energy of 120 MeV. A new $0^{+}$ state with 6% energy-weighted sum-rule strength was observed at $E_x=14.2\mathrm{}$ MeV. Two broad resonances (quadrupole and possibly octupole) were observed at $E_x\sim 18$ MeV. No resonant structure was observed at $E_x>20\mathrm{}$ MeV.

$\beta$-decay data from nuclei with $17<~A<~39$ are analyzed with full $\mathrm{sd}$-space shell-model wave functions to determine the effective values of the single-particle matrix elements of the Gamow- Teller operator between all combinations of $\mathrm{sd}$-shell orbitals.

An oscillatory dependence on ionic charge of total electron-capture cross sections has been observed for multiply charged heavy projectiles incident on an atomic hydrogen target. The oscillatory behavior is attributed to interference caused by the long-range Coulomb and a short-range (screened Coulomb) force acting on the captured electron. The oscillations are superimposed on a monotonically increasing variation with ionic charge. This monotonic increase is also found for lighter ions.

The doubly differential cross section resulting from electron loss of 0.5-MeV ${\mathrm{H}}^{-}$ ions in collisions with Ar were measured from 0° to 173°. The singly differential cross section (SDCS), angular distribution, for the $v_e\approx v_i$ group was integrated over solid angle and normalized to the known total electron-loss cross section. This SDCS was found to be dissimilar to that predicted by an electron scattering model previously used to describe projectile ionization. However, the SDCS was found to resemble, with some notable differences, the elastic scattering of electrons from Ar.