The neutral decay modes of the $\eta$ are observed by detecting the resulting $\gamma \text{'}\mathrm{s}$ in a lead-plate spark-chamber array. The $\eta \text{'}\mathrm{s}$ are produced in the reaction ${\pi }^{-}+p\to n+\eta$, at 707 MeV/c. The neutron is detected with scintillators and its energy measured by a timeof flight technique. Our results for the neutral branching ratios are $2\gamma =(57.9\mathrm{}\pm 5.2)\%$, ${\pi }^0\gamma \gamma =(24.4\mathrm{}\pm 5.0)\%$, $3{\pi }^0=(17.7\mathrm{}\pm 3.5)\%$.

In the reaction ${\pi }^{-}+p\to {\pi }^{-}+{\rho }^0+p$ at 8 GeV/c, we find that the $A_1$ can be explained as a kinematic effect due to a Deck-type mechanism, but only if both $\pi$ and $\rho$ exchanges are included. We also present evidence for a possible ${\pi }^{-}{\rho }^0$ resonance at 1190 MeV with a width of 17 MeV.

The binding energy of magnetically induced bound states has been measured in $n$-InSb subjected to intense magnetic fields and found to be in agreement with theoretical predictions. Observations of quantum-limit scattering and impurity conduction are discussed.

We propose a new phenomenon, the "Magneto-Quantum-Electric Effect," based on the lateral displacement of the centers of the cyclotron orbits of the carriers when the momenta transferred to the carriers from phonons or photons have components in the plane of the orbits in real space. We discuss the magnitude of the effect for a compensated and an uncompensated plasma, and also its effect on the absorption constant of phonons or photons.

We report the observation of magneto-quantum-electric fields associated with the giant-quantum attenuation of sound waves in bismuth. For suitable orientations of $\overrightarrow{\mathrm{q}}$ and ${\overrightarrow{\mathrm{H}}}_0$, a set of voltage peaks appears, whose magnetic-field dependence and the magnitudes are in good agreement with theory. Voltage peaks also appear in a direction corresponding to transverse electric fields set up by the longitudinal acoustoelectric current and the anisotropic resistivity of bismuth.

The energy of the first rotational nuclear gamma ray of ${\mathrm{Sm}}^{152}$ in the presence of a muon in a $1s$ state has been found to be 1.03±0.15 keV greater than the normal transition energy. This type of measurement provides a method of determining the change in mean square radius between ground and excited states (isomer shift) in deformed nuclei.

An isomer shift has been observed in the Mössbauer study of the 121.8-keV ($2^{+}$→$0^{+}$) transition in ${\mathrm{Sm}}^{152}$. A value of ${\left(\frac{\Delta 〈R^2〉}{〈R^2〉}\right)}_{2-0}=(10\mathrm{}\pm 3)\times {10}^{-4\mathrm{}}$ is deduced, based on isotope shift data for ${\mathrm{Sm}}^{152}$ and ${\mathrm{Sm}}^{154}$. This value disagrees with present theoretical prediction. In particular, the influence of the $\beta$ band in ${\mathrm{Sm}}^{152}$ can only account for about 20% of the observed stretching.

We describe a new source for dynamical gravitational fields consisting of an acoustically stressed volume of matter. The very-near-zone dynamical gravitational fields are measured as a function of distance and azimuthal angle, using apparatus responsive to the curvature tensor. The high frequency of 1660 cycles per second implies a new regime for gravitational technology.

In recent work, fits to certain elastic pion-nucleon data were obtained by adding a resonance amplitude and Regge-trajectory exchange amplitude. We show that the $s$-channel resonance amplitude considered in this recent work is, by itself, satisfactory to explain the backward ${\pi }^{-}p$ scattering; i.e., it is shown that the need for a baryon-trajectory exchange amplitude is not established.

We evaluate the phase of the $K^{+}$-nucleon forward-scattering amplitude from dispersion relations and find a qualitative difference between the $I=0\mathrm{}$ and $I=1\mathrm{}$ state. With assumptions for the background contributions to the amplitude, we present evidence for an $S=+1\mathrm{}$, $I=0\mathrm{}$ resonance.

A new sum rule for the pion-scattering amplitude $B^{+}(\nu , t)$ is derived from a superconvergence assumption and its saturation is discussed. A similar sum rule for the amplitude $F^{-}(\nu , t)$ is also obtained and its consequences are examined.