The modulation of the $L_{\mathrm{III}}$ x-ray emission band of copper due to an alternating elastic strain is reported for the first time. The technique is useful for the determination of deformation potentials and for the locations of critical points and the Fermi energy in the electronic band structure.

In phonon-propagation studies using heat pulses it has been found that predominantly transverse phonons are observed for [100] propagation in LiF whereas mainly longitudinal phonons are observed for this direction in KCl. This result and similar effects previously reported on other crystals are explained in terms of a phonon-focusing effect that arises from elastic anisotropy.

We have obtained the charge and spin susceptibilities in the ferromagnetic state of an electron gas, including the effects of the long-range nature of the Coulomb interaction from a unified point of view. The susceptibilities are discussed as a function of the magnetization for typical ferromagnetic alloy systems.

The half-life of the low-energy isomeric state of ${\mathrm{U}}^{235}$ produced by α decay of ${\mathrm{Pu}}^{239}$ was measured as a function of various metallic environments. The results show a correlation between the half-life and the average electronegativity of the host metal. In addition, effects due to impurity diffusion of U in metals at room temperature are observed.

In a stopping-$K^{-}$ exposure of the Brookhaven National Laboratory 30-in. hydrogen bubble chamber, we have found 204 $\Lambda$ $\beta$ decays, $\Lambda \to p+e^{-}+{\overline{\nu }}_e$, with a scanning efficiency of 0.97±0.02. We obtain a branching ratio of (0.80±0.08)×${10}^{-3\mathrm{}}$. Using SU(3) and conservation of vector current to determine the weak-magnetism to vector form-factor ratio in the baryon current, we find an axial-vector-to-vector ratio of ${0.72}_{-0.14\mathrm{}}^{+0.19\mathrm{}}$. The results are in good agreement with Cabibbo theory and are insensitive to the relative strength of weak magnetism.

We present the results of a study of ${K_L}^0$ decays observed in the CERN 1.1-${\mathrm{m}}^3$ heavyliquid bubble chamber. About 75 000 frames were scanned, and yielded some 7500 examples of isolated ${K_L}^0$ decays to charged particles. Based on a sample of 4000 events in a restricted fiducial region, the following branching ratios were found: $\frac{N({K_L}^0\to {\pi }^{\pm }{\mu }^{\mp }\nu )}{N({K_L}^0\to {\pi }^{\pm }{e}^{\mp }\nu )}=0.648\mathrm{}\pm 0.030,$ $\frac{N({K_L}^0\to {\pi }^{+}{\pi }^{-}{\pi }^0)}{N({K_L}^0\to \mathrm{all}\mathrm{charged})}=0.157\mathrm{}\pm \mathrm{0.010.}$

The off-mass-shell behavior of the $S$-wave $\pi \pi$ amplitude predicted by Weinberg implies that the $S-P$-wave interference term in pion production vanishes for certain values of momentum transfer and $\pi \pi$ effective mass. Such behavior is shown to be consistent with experiment. The analysis determines the ratio of scattering lengths and the isospin content of the sigma commutator of current algebra.

We have studied the reaction $\overline{p}+p\to {\pi }^{\mp }+B^{\pm }$ with small momentum transfer to the pion at 6 and 8 GeV/c. For $B^{+}\equiv {\pi }^{+}$ the average differential cross sections $\frac{d\sigma }{\mathrm{dt}}$ are 4.6±1.9 μb/${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ for $-0.08\mathrm{} {\left(\frac{\mathrm{GeV}}{c}\right)}^2>t>-0.16\mathrm{} {\left(\frac{\mathrm{GeV}}{c}\right)}^2$ at 6 GeV/c, and 1.5±0.6 μb/${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ for $-0.07\mathrm{} {\left(\frac{\mathrm{GeV}}{c}\right)}^2>t>-0.45\mathrm{} {\left(\frac{\mathrm{Gev}}{c}\right)}^2$ at 8 GeV/c. At 8 GeV/c the cross sections are 0.56±0.33 μb/${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ for $B^{-}\equiv {\pi }^{-}$ and 1.9±1.1 μb/${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ for $B^{-}\equiv {\rho }^{-}$ averaged over the momentum-transfer interval $-0.05\mathrm{} {\left(\frac{\mathrm{GeV}}{c}\right)}^2>t>-0.46\mathrm{} {\left(\frac{\mathrm{Gev}}{c}\right)}^2$.

The predictions of an algebraic model are compared with the experimental meson mass spectrum.

Based on the current-current theory of weak interactions the $\Delta I=\frac{1}{2}$ rule for nonleptonic decays is derived from a dynamical mechanism that satisfies duality and absence of resonances in exotic channels.

We report a calculation of the three-photon-exchange (electron-loop) contribution to the sixth-order anomalous magnetic moment of the muon. Our result, which contains a logarithmic dependence on the muon-to-electron mass ratio, brings the theoretical prediction into agreement with the CERN measurements, within the 1-standard-deviation experimental accuracy.

The existence of exotic mesons is inferred from the apparent splitting of the $A_2$ peak.

The commutation rules of the algebra of fields have been applied to predict sum rules for the electric-dipole moment and the magnetic-quadrupole moment of nucleons. In the calculation it was assumed further that the sum rule could be saturated by just one state [$N^{**}\mathrm{}\left(1518\right)\mathrm{}$]. The resulting consistency condition obtained is in striking conflict with experimental results. The identical condition is obtained if one assumes saturation of the sum rule by an arbitrary number of one-particle states. This failure of the consistency condition based on the algebra of fields is to be contrasted with the reasonable success of the corresponding relation based on current algebra and saturation by the same single state.

On the basis of chiral dual dynamics it is shown that the square of the mass of any non-exotic strange or nonstrange meson or baryon of nonvanishing isospin (with the possible exception of $I=1\mathrm{}$ baryons) must be an integer multiple of the "quantum" $\frac{1}{2}{m_{\rho }}^2$. It is found than the strength of SU(3) breaking can only take certain discrete values.

It is demonstrated that the amplitude for elastic electron-hydrogen atom scattering above ionization threshold can be calculated by using a variational method at several complex energies and continuing into the physical region numerically.

We have investigated the afterglow decay rates of the Zn II laser lines in spontaneous emission. Measurements indicate that the dominant mechanism for excitation of these lines is thermal-energy charge-transfer collisions between zinc atoms and both atomic and molecular ions of helium.

The problems of resistive diffusion and of rotation about the magnetic axis in toroidal systems are considered. They are shown to be related to the question of stability of drift-acoustic waves on which viscosity has an important influence. A nonrotating state is always unstable, but if the appropriate criterion is satisfied, there are stable rotating states for which an enhanced diffusion is calculated.

The structure factor $S\left(k\right)\mathrm{}$ of liquid helium-4 obtained by scattering experiment shows a substantial deviation from the Feynman prediction for small $k$ values. By attributing this discrepancy to the existence of a usually overlooked short-range structure in gaseous helium, the data of Gordon, Shaw, and Daunt are reanalyzed. The experimental $S\left(k\right)\mathrm{}$ now shows an improved agreement with the theoretical prediction. A further experimental verification is suggested.

It is shown theoretically that the motion of liquid crystals through capillaries may resemble that of a plug, the velocity profile being flat rather than parabolic.

In agreement with a recent theoretical prediction of de Gennes, the transition temperature of In (or another superconductor) films sandwiched between two magnetic films depends on the relative orientation of the magnetization of these ferrites. The highest transition temperature (nearly the $T_c$ of bulk In, 3.4°K) is obtained when the two ferrites are deposited in antiparallel magnetic fields, while the lowest (≃1°K) occurs when the ferrites are deposited in parallel magnetic fields. The depression of the transition temperature of an indium film sputtered or evaporated between two magnetic films magnetized in parallel fields is inversely proportional to the thickness of the In film.