A classification of the Yang-Mills fields is presented using spinor methods. Each class of fields is associated with certain values of five invariants, of which four are complex and one is real. The whole classification is described in terms of two diagrams.

We observe a resonance in the total cross section for hadron production in $e^{+}{e}^{-}$ annihilation at a mass of 3772±6 ${\mathrm{M}\mathrm{e}\mathrm{V}/\mathit{c}}^2$ having a total width of 28±5 ${\mathrm{M}\mathrm{e}\mathrm{V}/\mathit{c}}^2$ and a partial width to electron pairs of 370±90 ${\mathrm{e}\mathrm{V}/\mathit{c}}^2$.

A $\mathrm{GL}(2n, C)$ gauge theory of strong interactions with an Einstein-Cartan-Dirac-type Lagrangian is proposed, much like that of Salam. The model not only yields a generalized Heisenberg-Pauli nonlinear field equation for the fundamental spinor fields, but also strongly indicates a complete quark confinement due to a built-in geometrodynamical mechanism. A mass formula for baryons, a possible bearing of the Hawking process on the concept of a universal hadronic temperature, and $f$-quantum geometrodynamics are discussed.

Levels in ${}_{}{}^{151}{}_{}{}^{}\mathrm{Eu}$ were populated using the ($d, t$) reaction. Most of the cross section is concentrated between an excitation energy of 2.2 and 2.6 MeV while levels below 261 keV were not observed. We interpret this as evidence for the coexistence of three distinct shapes in ${}_{}{}^{151}{}_{}{}^{}\mathrm{Eu}$.

Anomalies which were previously reported in the intensity ratios of electron capture to positron emission for $\beta$ transitions from ${}_{}{}^{145}{}_{}{}^{}\mathrm{Gd}$ to 12 levels in ${}_{}{}^{145}{}_{}{}^{}\mathrm{Eu}$ have been shown to be nonexistent. The $\gamma$ spectrum of ${}_{}{}^{145}{}_{}{}^{}\mathrm{Gd}$ has been measured and the total $\beta$ feeding to high-energy levels has been estimated. A revised $Q$ value was determined: $Q_{\epsilon }=5.00\mathrm{}\pm 0.07$ MeV.

The spectrum of high-energy $\delta$ rays emitted in an 83-MeV (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$) collision is measured. The data are compared with the scaled Born approximation and the adiabatic monopole model.

Nanosecond time-resolved absorption spectroscopy is used to study the populations of the $2{}_{}{}^1{}_{}{}^{}P$, $2{}_{}{}^3{}_{}{}^{}P$, $2{}_{}{}^1{}_{}{}^{}S$, and $2{}_{}{}^3{}_{}{}^{}S$ levels in a high-pressure He discharge. At high pressures, the population of the $2{}_{}{}^1{}_{}{}^{}P$ level decays primarily through three-body molecular formation involving two ground-state He atoms at a rate of (3.5 ± 0.8) × ${10}^{-31\mathrm{}}$ ${\mathrm{cm}}^6$ ${\sec }^{-1\mathrm{}}$. The population of the $2{}_{}{}^3{}_{}{}^{}P$ level decays primarily as a result of mechanisms other than collisions involving ground-state He atoms.

Superfluorescence is reported from an initially inverted, pure two-level system. Single-pulse emission occurs at low densities; neither homogeneous relaxation nor inhomogeneous dephasing nor linear diffraction can explain the absence of ringing. At higher densities multiple-pulse outputs occur. The experimental results are not in good quantitative agreement with present theories.

The motion of an ion in the presence of a constant magnetic field and a perpendicularly propagating electrostatic wave with frequency several times the ion cyclotron frequency is shown to become stochastic for fields satisfying $\frac{E}{B_0}>\frac{1}{4}{\left(\frac{\Omega }{\omega }\right)}^{\frac{1}{3}}\left(\frac{\omega }{k}\right)$. This stochasticity condition is independent of how close $\omega$ is to a cyclotron harmonic. Applications of current interest in supplementary heating of plasmas with rf power near the lower-hybrid frequency are suggested.

Experiments have shown that glasses, at low temperatures, possess an anomalous specific heat above that due to the lattice vibrations. Using two parameters I fit the contribution of a new excitation to the experimental specific-heat data. An experiment to test the theory is suggested.

Thermal conductivity measurements on samples of $p$-Ge down to 50 mK indicate the presence of an approximately Gaussian distribution of resonant scattering frequencies which has a width $\Delta \sim 30$ GHz. The data suggest that this is due to about half of the acceptors which are in distorted sites while the other half are relatively free from distortion. The "two-site" model reconciles disagreements in linewidth from different types of experiment. We obtain a value for ${D_{u^{\prime }}}^a\left(\mathrm{dynamic}\right)=4.1\mathrm{}\pm 0.4$ eV.

Results of a mean-field treatment of deuterium impurities in hydrogen-bonded ferroelectrics are compared with observations of the critical central peak in potassium dihydrogen phosphate. The natural abundance of deuterium accounts quantiatively for the relative strength and temperature dependence of the peak. Its slow dynamics and the absence of a similar feature in cesium dihydrogen arsenate are commented on.

We present measurements of the equilibrium and mean-square fluctuation in vortex-line density in turbulent He II. The equilibrium values are in good agreement with the Vinen theory and other current experimental results. The fluctuating quantities are described by the general instability theory reviewed by Haken.

The spin polarization of field-emitted electrons from the (100) plane of field-evaporated Ni single-crystal tips is observed to decrease from -(3.0±1)% to (0±1)% upon hydrogen adsorption (full coverage). We interpret these results as evidence for a strong reduction of the ferromagnetism of the $d$ electrons of the Ni surface atoms upon hydrogen chemisorption.

Nuclear magnetic resonance has been observed in ferromagnetic Ni near the critical temperature. The nuclear spin-spin and spin-lattice relaxation rates are found to become equal in the critical region below $T_C$ and diverge with a critical exponent $n^{\prime }=0.67\mathrm{}\pm 0.08$. Spin-lattice relaxation rates in the paramagnetic state exhibit only incipient spin-fluctuation enhancement within the experimental range. Measurements of the ferromagnetic NMR frequency near $T_C$ and of the Knight shift above $T_C$ are described.

First-principles electronic—band-structure calculations and measured phonon properties are employed in a calculation of the concentration dependence of the superconducting transition temperatures for $\mathrm{Pd}{\mathrm{H}}_x$ and $\mathrm{Pd}{\mathrm{D}}_x$, including the inverse isotope effect. Excellent agreement with the experimental results is obtained. Our model also gives a qualitative understanding of the enhanced transition temperatures in the palladium-noble-metal hydrides.

An atom-probe field-ion microscope was successfully employed for the first time to study semiconductor Si surfaces. Using a magnetic-sector type we have observed pure silicon ${\mathrm{Si}}^{+}$, monohydride Si${\mathrm{H}}^{+}$, and dihydride Si${\mathrm{H}}_2^{+}$, ions from the well-ordered H-covered (111) and (110) planes, and pure silicon ${\mathrm{Si}}^{+}$, monohydride Si${\mathrm{H}}^{+}$, and silane Si${\mathrm{H}}_4^{+}$ ions from the disordered (311) areas. This observation is taken as the evidence for the formation of the silicon dihydride and trihydride surface phases suggested by recent ultraviolet photoemission studies.

In view of the large amount of experimental evidence in support of a cluster description of the spin-glasses, we propose and solve a mean-field model of these systems in which dynamical clusters are the basic entity. The model can explain an important and unresolved puzzle: why the susceptibility has a cusp at a freezing temperature $T_c$, while the specific heat has a rounded maximum at a significantly higher temperature.

We present generalized Einstein equations, invariant under scale transformations, and study several astrophysical tests. It is assumed that the dynamics of atoms or clocks used as measuring apparatus is given a priori. Connection with gauge fields and broken symmetries is made through the cosmological constant.

We have analyzed data taken in the CERN narrow-band neutrino and antineutrino beams with regard to the "high-$y$ anomaly" observed by previous experiments at Fermilab. At neutrino energies between 30 and 200 GeV, the $\overline{\nu }$ and $\nu$ charged-current cross-section ratios and muon-inelasticity distributions disagree with the earlier results. In particular, there is no evidence for energy-dependent effects in the antineutrino data which constitute an important aspect of the alleged anomaly.