The charge asymmetry $\delta =\frac{({\Gamma }_{+}-{\Gamma }_{-})}{({\Gamma }_{+}+{\Gamma }_{-})}$ for the electron in the decay of the long-lived neutral kaon to pion, electron, and neutrino has been measured. We find asymmetry $\delta =(+2.24\mathrm{}\pm 0.36)\times {10}^{-3\mathrm{}}$. The result shows that $\mathrm{CP}$ symmetry is not conserved in this process.

It is noted that the nonzero charge asymmetry in the ${\left(K_L\right)}_{e3\mathrm{}}$ decay demonstrates the nonorthogonality of the ${K_L}^0$ and ${K_S}^0$ states. The result of the foregoing Letter on the charge asymmetry, combined with other measurements relevant to $\mathrm{CP}$ nonconservation in $K$ decay, are found to be consistent with a phenomenological analysis, which yields a pion-pion scattering phase shift consistent with other indirect observations only if the mass difference $m_L-m_S$ is negative.

New results are reported for the equilibrium constant-volume heat capacity of xenon measured isothermally under completely static (unstirred) conditions at critical average density. The shift of the heat-capacity singularity to slightly below the reported phase-transition temperature is observed here as it has been for argon and oxygen. An explanation of this effect is suggested.

The cyclic temperature dependence of two stimulated Raman lines of benzene is reported. These data are inconsistent with the self-focusing theory for the anomalous gain.

We have discovered a positive isotope effect in superconductors. The relation between the transition temperatures of ${\mathrm{U}}^{235}$ and ${\mathrm{U}}^{238}$ can be described by $T\sim M^2$.

The recent suggestion that the flux-flow current-voltage characteristics of Type-II superconductors can be described by the relation $\ln I\propto V^{\frac{1}{2}}$ is shown to be inadequate over an extended range of currents. The previously reported linear relationship between $I$ and $V$ is found to hold and the present ideas about flux flow remain unchallenged.

Magnetization measurements were carried out on cylindrical samples of pure tin with diameters of 7, 10, and 122 μm and very clean and smooth surfaces in the temperature range from 3.62 to 3.72°K. The magnetization was found to be reversible and linear with the applied field $H_0<H_{\mathrm{sh}}$. Considerable superheating up to fields $H_{\mathrm{sh}}=2.25\mathrm{}{H}_{\mathrm{cb}}$ has been observed.

The low-lying energy levels of a paramagnetic chain in the presence of spin-phonon interaction have been investigated. It is shown that there is no gap in the one-particle excitation spectrum.

We show that the driving force for the spiral-to-ferromagnet transition in Dy and Tb is the energy of cylindrical symmetry associated with the lowest order magnetostriction effects. We also point out that the experimental temperature dependence of the spinwave energy gap for Tb does not agree with that calculated using the frozen-lattice approximation suggested by Turov and Shavrov for magnetoelastic effects.

Experimental evidence is given to show that the magnetocrystalline anistropy of silicondoped yttrium iron garnet, nominal composition ${\mathrm{Y}}_3$${\mathrm{Fe}}_{4.9}$${\mathrm{Si}}_{0.1}$${\mathrm{O}}_{12}$, can be changed by more than 100 Oe at 20°K through irradiation with near-infrared photons. The change is interpreted as due to the redistribution of electrons between iron ions, that is valence exchange.

The ground state of a paramagnetic impurity recently proposed by Kondo is studied both variationally and with perturbation theory. It is shown that the ground state is stable to perturbations from the nondiagonal part of the Hamiltonian. In addition, the low-temperature properties of the system are obtained.

A method is presented for calculating two-body shell-model interaction matrix elements from scattering phase shifts, which applies to shifts of any magnitude and to tensor coupling. It is assumed that the average (shell-model) potential, expressed in two-nucleon relative coordinates, is slowly varying within the range of the free two-nucleon interaction. Examples are given for the $p$ shell and compared with the results of other methods, some of which include Pauli corrections.

A method is presented for calculating two-body shell-model interaction matrix elements from scattering phase shifts, which applies to shifts of any magnitude and to tensor coupling. It is assumed that the average (shell-model) potential, expressed in two-nucleon relative coordinates, is slowly varying within the range of the free two-nucleon interaction. Examples are given for the $p$ shell and compared with the results of other methods, some of which include Pauli corrections.

The relativistic O(4, 2) dynamics is applied in its simplified version to meson decays with spin parity $2^{+}$→$1^{-}$+$0^{-}$, $2^{+}$→$0^{-}$+$0^{-}$, $1^{-}$→$0^{-}$+$0^{-}$ in good agreement with experiment.