The neutron scattering from the magnetic excitations in the substitutionally disordered antiferromagnet, ${\mathrm{Mn}}_{0.68}$${\mathrm{Zn}}_{0.32}$${\mathrm{F}}_2$, has been measured. The results show structure in the line shape which is similar to that predicted by some of the calculations based on the coherent-potential approximation and to that obtained in recent computer simulations.

Recently reported observations in $e^{+}{e}^{-}$ collisions suggest the existence of a heavy lepton $L^{\pm }$ with a mass $\sqrt{s}\sim 2$ GeV. I predict that a heavy prositronium atom exists, which is an $L^{+}{L}^{-}$ bound state. Its detection would confirm the existence of a heavy lepton. A way is suggested to detect this heavy atom by looking for an x-ray signal of a specific energy in $e^{+}{e}^{-}$ collisions.

A new anomaly-free gauge model based on an SU(2) ⊗ SU(2) ⊗ U(1) group is proposed with 32 quarks and leptons. The model permits a dominantly $I=0\mathrm{}$ neutral current, predicts $R\simeq 6\frac{2}{3}$, explains the $\Delta I=\frac{1}{2}$ rule, and allows the charmed quark to decay predominantly to nonstrange particles.

We have found evidence for jet structure in $e^{+}{e}^{-}\to \mathrm{hadrons}$ at center-of-mass energies of 6.2 and 7.4 GeV. At 7.4 GeV the jet-axis angular distribution integrated over azimuthal angle was determined to be proportional to $1+(0.78\pm 0.12){cos}^2\theta$.

The ratio of prompt negative muons to negative pions produced in the forward direction by the interaction of 400-GeV protons on copper has been determined to be 5.8 × ${10}^{-5\mathrm{}}$ for 55-GeV muons, 3.05 × ${10}^{-5\mathrm{}}$ for 102-GeV muons, and 1.93 × ${10}^{-5\mathrm{}}$ for 230-GeV muons. The ratio of prompt positive muons to negative muons was about 1.

The photoproduction of the $\psi \mathrm{}\left(3100\right)\mathrm{}$ meson from a beryllium target has been measured using an 11.8-GeV bremsstrahlung beam. The energy and angular dependence of the measured spectra may be obtained from an elastic nucleon cross section of the form $\frac{d\sigma }{\mathrm{dt}}=(1.01\mathrm{}\pm 0.20)\exp \left[\right(1.25\mathrm{}\pm 0.20\left)t\right]$ nb/Ge${\mathrm{V}}^2$. This cross section is exceedingly small in comparison with those of the other vector mesons.

We have measured the ratio of the magnetic moment of the electron in hydrogen to the magnetic moment of the proton in ${\mathrm{H}}_2$O to be $\frac{g_j\left(\mathrm{H}\right)}{{g_p}^{\prime }}=658.216\mathrm{}0091\left(68\right)\mathrm{}$ [10 parts per billion (ppb)], at a temperature of 34.7°C. This yields a value for the proton moment in Bohr magnetons of $\frac{{{\mu }_p}^{\prime }}{{\mu }_{\mathrm{B}}}=0.001\mathrm{}520992983\left(17\right)\mathrm{}$ (11 ppb). Our result differs from the currently accepted value by 150 ppb.

The recent installation of a polarized-triton-ion source on the Los Alamos Scientific Laboratory tandem Van de Graaff accelerator has allowed the measurement of analyzing powers for triton elastic scattering over a wide range of angles. The data obtained from scattering polarized tritons on ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$, ${}_{}{}^{60}{}_{}{}^{}\mathrm{Ni}$, ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ show unexpectedly large analyzing powers at backward angles. This leads to spin-orbit well depths greater than predicted by an optical-model analysis based on folding-model calculations.

I propose a theory for the orientation and alignment of atomic states following atomicbeam passage through foils tilted through angle $\alpha$ from normal incidence. The final encounters within the foil operate on the existing foil-induced alignment, producing orientation and altered alignment. Within theoretical limitation, tensorial components transforming as angular momentum components in the collision frame vary as $tan\alpha$, while those associated with the squares of components contain a ${tan}^2\alpha$ dependence, in substantial agreeement with observation.

Resonant laser light causes micron-sized particles to form in cesium vapor when a small amount of hydrogen gas is present in the vapor. The particles are identified as cesium-hydride crystals. This is the first observation of light-induced particle formation in metal vapors. The phenomenon has relevance to lasers and nonlinear optical devices based on dense alkali vapors, and it may also be of interest for laser isotope-separation schemes.

In order to check the discrepancy between calculation and experiment in muonic atoms, we have remeasured the $5g-4f$ transitions in Pb and the $5g-4f$ and the $4f-3d$ transitions in Ba. Our new results show no discrepancy and confirm recent theoretical calculations of vacuum polarization to within 0.5%.

The threshold for stimulated Brillouin backscattering in a weakly inhomogeneous plasma in the presence of a low level of Langmuir turbulence has been estimated. Such background turbulence is found to induce a small space-dependent wave-number mismatch through the modified ion-acoustic-wave dispersion relation, leading to convective saturation of the scattered wave. The threshold values are found to be quite significantly altered compared to those calculated for quiescent plasmas.

The stability criterion of the internal kink mode is given in toroidal geometry for plasmas with circular cross sections. Contrary to known results in cylindrical geometry, the internal kink mode can be stable if the pressure gradient is sufficiently low.

Charged-particle motion across a sheared magnetic field and electrostatic wave is studied. Resonant-particle orbit widths are derived; two parametric dependences are found in the limits that the particle is near or far from the $k_{\parallel }=0\mathrm{}$ plane, with a smooth transition between the two. The orbit widths are used to calculate diffusion coefficients in tokamak-type configurations. These predictions are confirmed by test-particle computer simulations in ($x, y, v_x, v_y, v_z$) coordinates employing a Monte Carlo collision operator.

Orbital waves in the $A$ phase of superfluid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ are shown to be essentially diffusive. The weak-coupling expression for the "angular superfluid density" tensor $\overleftrightarrow{\mathrm{C}}$ is obtained.

The formation of mesonic atoms in condensed matter is calculated with a parameterfree classical model. The probability for Coulomb capture is found to be proportional to $Z^{\frac{1}{3}}\ln \mathrm{}(0.57Z)\mathrm{}$. It is shown by a ${\chi }^2$ test performed for metal halides that the new formula reproduces well the experimental data.

We report neutron-scattering measurements on highly supercooled liquid gallium droplets showing a vanishing quasi-elastic frequency width as the temperature is reduced. The width tends towards zero at a temperature within 1 standard deviation of the value $T_L=150\mathrm{}\pm 1$ K at which gallium is always observed to become crystalline. This suggests the interpretation of $T_L$ as a metastability limit, below which the liquid state becomes unstable with respect to infinitesimal fluctuations.

Measurements are presented of the magnetization $M$ up to 50 kG between 1.8 and 4.2 K and the susceptibility $\chi$ from 1.8 to 100 K of three dilute $\mathrm{Ag}\mathrm{Mn}$ alloys of nominal concentrations 630, 1000, and 1370 ppm Mn. Both $M$ and $\chi$ follow scaling laws well. The strength $V_0$ of the Ruderman-Kittel-Kasuya-Yosida interaction between two Mn impurities has been determined from expressions for the high-field behavior of $M$ in the presence of such interaction, yielded by a virial expansion of the free energy. The value for $V_0$ is (2.4±0.4) × ${10}^{-25\mathrm{}}$ eV ${\mathrm{cm}}^3$. The effective $\mathrm{}\left|J\right|\mathrm{}$ value estimated from $V_0$ is 0.7±0.1 eV.

Thermoreflectance measurements on LiF and KCl were made from 10 to 30 eV using synchrotron radiation. Analysis of the differential dielectric and electron-energy-loss functions shows that the energy-loss peak generally attributed to the valence plasmon actually arises from the plasmon and overlapping longitudinal-exciton-like peak(s).

We have measured the stabilized coloration produced from the conversion of $U$ centers in KCl by means of a two-photon process. The measurements show that the coloration involves energy transfer via electron-hole pairs, rather than direct photoexcitation of the $U$ centers. The absolute two-photon absorption cross section of KCl at $\lambda =266\mathrm{}$ nm was determined.