No ${\Sigma }^{+}\to n+l^{+}+\nu$ decay was found in a rapid scan of 550 000 hydrogen bubble chamber pictures exposed to a stopping $K^{-}$-meson beam. Based on the 260 ${\Sigma }^{-}\to n+l^{-}+\overline{\nu }$ events found in the same scan, the upper limit (90% confidence level) for the ratio of ${\Sigma }^{+}$ to ${\Sigma }^{-}$ leptonic decay rates is 0.034.

Differential spin-exchange scattering of sodium from cesium has been observed by the crossed-atomic-beam scattering technique. The angular dependence of the exchange probability yields details of the singlet-triplet potential differences, including the depth and position of the triplet potential minimum. Results are also reported for potassium scattering from molecular oxygen.

We have measured the differential spin-exchange cross section ${\sigma }_{\mathrm{ex}}\left(\theta \right)$ relative to the differential cross section $\sigma \left(\theta \right)$ for the scattering of 0.5-eV electrons by potassium, for angles between 10° and 180° in the electron polar scattering angle. The ratio $\frac{{\sigma }_{\mathrm{ex}}\left(\theta \right)}{\sigma \left(\theta \right)}$ increases monotonically from approximately 0 at 10° to 0.7 ± 0.1 at 180°.

The osmotic pressure of dilute solutions of ${\mathrm{He}}^3$ in liquid ${\mathrm{He}}^4$ has been measured at 0.320, 0.650, and 1.16°K for ${\mathrm{He}}^3$ concentrations up to 2%. The results do not agree well with the calculations of Ebner based on the effective potential of Bardeen, Baym, and Pines.

The computation of a self-consistent Astron-type $E$ layer (uniform and unbounded in the axial direction) is briefly outlined and illustrated with some examples, with and without velocity spread in the electron distribution. The calculation is based on the explicit ingetration of the (relativistic) Vlasov equation for the electrons in terms of the (single-particle) constants of the motion.

The pressure dependence of the elastic constants of CsCl, CsBr, and CsI was measured up to 10 kbar by an ultrasonic technique and found to be nonlinear. The second pressure derivatives of the elastic constants and three linear combinations of the fourth-order elastic constants were determined.

Eigenvalues of finite translations are used for specifying a complete set of states in quantum mechanics. A derivation of these states is given and they are shown to be very useful in solid-state physics.

We attempt here a limited experimental test of a recent speculation that the Regge residue function, $\beta \mathrm{}\left(s\right)\mathrm{}$, shows an exponential or faster decrease with $\alpha \mathrm{}\left(s\right)\mathrm{}$ as $s\to \infty$ to insure polynomial boundeness for the total amplitude.

Calculations are presented which suggest that a suitable molecular-beam resonance experiment can form a sensitive test for the existence of an electric dipole moment on the proton.

We study the generalized superconvergent sum rules for a number of processes of the kind $P+P\to P+V$, where $P$ and $V$ stand for pseudoscalar and vector mesons, respectively. We find simple algebraic equations for the parameters of the leading Regge trajectories which are exchanged. The results are in good agreement with experiments. The limit of SU(3) symmetry is also considered.