We have measured electronic Raman scattering by the neutral acceptors Zn and Mg in GaP and have observed transitions between the degenerate orbitals of the ground state, transitions to higher bound states, and transitions to the valence band. We also observe a phonon wing accompanying the lowest electronic transition.

If internal photon propagators in the vacuum polarization tensor are replaced by $\frac{1}{q^2}$, the divergent part of ${Z_3}^{-1\mathrm{}}$ in quantum electrodynamics is ${\left({Z_3}^{-1\mathrm{}}\right)}_{\mathrm{div}}=\frac{{\alpha }_0}{2\pi }\left[\frac{2}{3}+\frac{{\alpha }_0}{2\pi }-\frac{1}{4}{\left(\frac{{\alpha }_0}{2\pi }\right)}^2\right]\ln \frac{M^2}{m^2}$ to sixth order. The simple nature and negative sign of the last term encourage the search for a closed form for ${\left({Z_3}^{-1\mathrm{}}\right)}_{\mathrm{div}}$ which vanishes for ${\alpha }_0>0\mathrm{}$.

It is found that all of the weak, unidentified solar lines reported by Sinanoğlu, Skutnik, and Tousey in the vicinity of calculated "quark" transitions may be explained by weak electric-dipole transitions expected in the normal species. Avoidance of ambiguity through overlap with weak transitions of the normal species appears to require identification to better than ≈ 0.04 Å in the far-ultraviolet solar spectrum.

It is shown how to generalize the recent suggestion of de Alfaro, Fubini, Rossetti, and Furlan to arbitrary spin in a simple way.

We present $W$-spin selection rules which prohibit many resonances having high isospin and hypercharge from displaying dominant two-body decay modes, appearing as bumps in meson-baryon scattering cross sections, or being produced by simple peripheral meson exchange. Thus, present experimental evidence against the existence of these states is inconclusive, and a search for more complicated production mechanisms and decay modes is suggested.

The equation for the evolution of the electron velocity distribution, in a stable uniform electron-ion plasma, is extended to wave numbers so small that collisional damping exceeds Landau damping for electron plasma waves.

It is rigorously proved that at any nonzero temperature, a one- or two-dimensional isotropic spin-$S$ Heisenberg model with finite-range exchange interaction can be neither ferromagnetic nor antiferromagnetic. The method of proof is capable of excluding a variety of types of ordering in one and two dimensions.

The conductance of metal-metal oxide-metal tunneling junctions has been observed to increase at certain characteristic bias voltages. These voltages are identified with vibrational frequencies of molecules contained in the barrier.

The excitation energies of dipolar impurities such as O${\mathrm{H}}^{-}$ or C${\mathrm{N}}^{-}$ in alkali halides are calculated, using a modification of the Devonshire model in which it is assumed that the major contribution to the dipolar potential is due to the asymmetrical distortion of the lattice by the dipole.