Differential cross sections for backward ${\pi }^{-}d$ elastic scattering have been measured from 496 to 1050 $\frac{\mathrm{MeV}}{c}$. The differential cross sections are generally smooth and consistent with the presence of low partial waves. An enhancement in the 180° cross section is observed near 700 $\frac{\mathrm{MeV}}{c}$, with indications of a similar effect near 900 $\frac{\mathrm{MeV}}{c}$. This structure is discussed in terms of an $I=1\mathrm{}$, $B=2\mathrm{}$ state of an $N^{*}N$ effect associated with the deuteron.

Photons in the visible region, detected in coincidence with $\beta$ rays from a ${\mathrm{Sr}}^{90}$-${\mathrm{Y}}^{90}$ source, have been shown to be internal bremsstrahlung containing a small admixture of transition radiation.

The Mueller expansion of the forward three-body amplitude is used to deduce an expansion for the elastic two-body scattering amplitude at large angles. The first term in the expansion is compared with the data for large-angle elastic $\mathrm{pp}$ data, and is found to be in good agreement. Under special circumstances it is found that the ratio of the large-angle elastic differential cross section to the total cross section is a universal function of one variable independent of the process.

Analysis of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ ground-state ${\mu }^{-}$ capture leading to the ground state of ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ reveals that (1) the induced tensor contribution is negligible, the induced pseudoscalar contribution marginal (< 5% of the capture rate), and the weak-magnetism contribution sizable (∼ 20%); and (2) the Gamow-Teller operator $\overrightarrow{\mathrm{\sigma }}$ is the only nuclear multipole (∼ 99%) effective in the process. A more accurate measurement of the transition rate may yield a useful independent determination of the weak-magnetism form factor.

Satellites on either side of the ${\mathrm{H}}_{\beta }$ line of hydrogen are reported at a displacement from ${\mathrm{H}}_{\beta }$ corresponding to the plasma frequency ${\omega }_p$ and twice such frequency. This anomalous behavior of the ${\mathrm{H}}_{\beta }$ transition is correlated with an oscillating electric field associated with plasma turbulence.

We have observed spin polarization of photoelectrons emitted by solid alkali targets exposed to circularly polarized light. The polarization increases monotonically with increasing atomic number.

By application of a macroscopic quantum uncertainty principle to the flow of superfluid helium, one can understand the onset of third sound in thin helium films, and the large excess absorption of third sound in thick helium films.

Inelastic light scattering with frequency shifts from 10 to 150 ${\mathrm{cm}}^{-1\mathrm{}}$ has been measured in liquid and solid ${\mathrm{He}}^3$ and ${\mathrm{He}}^4$ under pressures up to 150 atm. In the hcp solids a transverse optic phonon was observed and resolved. In addition a broad peak was observed which is remarkably similar in both liquids and solids. In the solid this peak is interpreted as scattering from two or more damped, coupled phonons. Scattering intensities and spectral forms are compared with recent theoretical calculations.

We report accurate measurements of the increase, due to rotation, of the attenuation of second sound in an annulus. The measurements can be explained in detail by a vortex-free-region model in close agreement with theory, assuming a vortex-core parameter of 10 Å at 1.65 K. The range of agreement extends from the vorticity threshold to relatively high angular velocities.

The decay rate $\Gamma$ of the concentration fluctuations near the critical mixing point of 3-methylpentane-nitroethane has been measured as a function of the correlation length $\xi$ and the wave number $k$ in the range $0.1<~k\xi <~20$. We have confirmed the theoretical prediction that $\Gamma$ varies as $k^3$ in the critical regime. An analysis of $\Gamma$ as a function of $k\xi$ reveals deviations from the theory of Kawasaki, which are discussed.

With a resolution of ${10}^{-10\mathrm{}}$ J/°K the fluctuation heat capacity has been observed near $T_c$ in thin films of ${\mathrm{Bi}}_{0.4}$${\mathrm{Sb}}_{0.6}$. No indication of peaking was seen in the heat capacity near $T_c$. The heat-capacity transition when compared with the corrected resistivity transition is found to have approximately twice the width. This width is 3 times that predicted by Ferrell.

It is demonstrated theoretically that in a small-gap semiconductor with large spin-orbit interaction energy a sufficiently strong transverse electric field destroys the Landau diamagnetic quantization but not the Pauli paramagnetic quantization of the conduction band. In a zero-gap semiconductor of the HgTe type the transverse electric field below the critical strength causes crossing of electron and heavy-hole Landau levels, thus inducing a semiconductor-semimetal transition.

The electrodynamic phenomenon of void resonance is used to interpret anomalous structure reported by Donovan and co-workers in the uv dielectric constants of evaporated amorphous germanium. The resulting void parameters are consistent with the existence of a connected network of microcracks perhaps 6 Å in width, separating much larger islands of void-free material. The origin and consequences of these fissures are discussed, including the expectation that several film properties are anisotropic.

We report the results of an experiment to determine the bulk conductivity of a sheet of colloidal graphite paper with holes randomly punched in it. The behavior of the conductivity is found to be quite different from that of the percolation probability.

Electrical conduction in resistor networks with all but a fraction $p$ of the resistors removed is studied as a paradigm of classical transport in disordered materials. A self-consistent effective-medium theory provides a quantitative description of the model, except in a small critical region, where the scaling law ${\sigma }^{\propto }{(p-p_c)}^{\frac{8}{5}}$ is satisfied (in three dimensions), with $p_c$ the critical probability for bond percolation. It is also contrasted with a critical-path analysis recently developed for the study of hopping conduction.

It is shown that, in the cubic phase, the doubly degenerate ${\Gamma }_{12}$ mode is the only long-wavelength optical mode which is temperature dependent in the harmonic approximation. However, it does not become unstable on cooling because it would drive a shear acoustic mode unstable first. The elastic constants are calculated by the method of long waves. Only $C_{11}-C_{12}$ is temperature dependent. Its calculated values for ${\mathrm{Nb}}_3$Sn are in fair agreement with experiment.

We report our observation of magnon excitation in antiferromagnetic NiO by electron tunneling through single-crystal Ni-NiO-Pb junctions. We compare the derivative of the tunnel conductance of the junction with a realistic magnon density of states of NiO and show that the observed structures indeed reflect the one-magnon, two-magnon, and three-magnon density of states of NiO.

The variation of the Curie temperature $T_c$ for the weak ferromagnet Zr${\mathrm{Zn}}_2$ has been determined as a function of hydrostatic pressure up to 25 kbar. $T_c$ is found initially to decrease linearly with pressure at a rate $\frac{\partial T_c}{\partial P}=(-1.8\mathrm{}\pm 0.04)\times {10}^{-3\mathrm{}}$ °K ${\mathrm{bar}}^{-1\mathrm{}}$, followed by an abrupt change of slope at 7.5 kbar and a rapid fall, extrapolating to a critical pressure $P_c$ of 8.5 kbar for the destruction of ferromagnetism. The measured $T_c\mathrm{}\left(P\right)\mathrm{}$ curve agrees well with the relationship $T_c\mathrm{}\left(P\right)=T_c\mathrm{}\left(0\right)\mathrm{}{(1-\frac{P}{P_c})}^{\frac{1}{2}}$ which is derived from the theory of itinerant ferromagnetism.

We question the recent conclusion that a simple compound-nucleus interpretation fails for this reaction.

A two-potential formalism based on the equations of Alt, Grassberger, and Sanhas is used to generate elastic nucleon-deuteron scattering amplitudes by combing $P$- and $D$-wave nucleon-nucleon forces in first order with "exact" nucleon-deuteron scattering amplitudes for $S$-wave forces. Elastic differential cross sections at 14.1 MeV and nucleon polarizations at 10.04, 14.1, and 22.7 MeV are presented. The cross sections are very accurate while the polarizations are in qualitative agreement with experiment except at 22.7 MeV.