The intensity and angular width of superlattice reflections in low-energy electron diffraction from W(110)$p(2\mathrm{}\times 1)$-O are measured as the overlayer disorders. The width of the reflections increases with temperature, indicating a shrinking of island size. An adatom-adatom interaction energy is determined for this system by using a short-range-order model and calculating the diffracted intensity from a chain of atoms.

X-ray-diffuse-scattering measurements of tetrathiafulvalene tetracyanoquinodimethane (TTF-TCNQ) show structural evidence of a phase transition. The low-temperature three dimensional superlattice ($2a\times 3.7b\times \mathrm{Xc}$) is found to be preceded above 40 K by one-dimensional fluctuations or a one-dimensional distortion visible up to 55 K.

The experimentally determined drift velocity of excess electrons in $a$-Si${\mathrm{O}}_2$ as a function of field is reported. Saturation of the velocity-field curve above ${10}^7$ cm/sec provides evidence for phonon emission by significantly heated electrons. The data provide the first test of, and good agreement with, the Thornber and Feynman theory of electron energy loss in polar materials at high applied fields.

The charge-transfer complex tetrathiafulvalene-tetracyanoquinodimethane has been studied by x-ray-photoelectron spectroscopy at both normal and grazing electron takeoff angles. Changes in the ${\mathrm{N}}_{1s}$ and ${\mathrm{S}}_{2p}$ spectra with angle show that a discrete layer exists at the surface of the $a-b$ plane. Essentially zero electron transfer takes place in this layer versus ∼ 0.8±0.2 in the bulk. The surface layer is ca. 1 to 5 layers of complex thick and appears to be intrinsic to "good" organic conductors.

We show that electron-phonon coupling plays a major role in the spin relaxation of the isostructural family of organic metals, ${\left(\mathrm{TSeF}\right)}_x{\left(\mathrm{TTF}\right)}_{1-x}\mathrm{TCNQ}$ (tetraselenafulvalene tetrathiafulvalene tetracyanoquinodimethane). The dependence of this relaxation on the fraction of TSeF in the donor chain suggests a picture of hybridized donor-acceptor bands for TSeF-TCNQ in contrast to the nonhybridized bands of TTF-TCNQ.

NMR shifts $\Delta K$ and relaxation times $T_1$ of ${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$ satellite resonances corresponding to nuclei near impurities in $\mathrm{Cu}\mathrm{Fe}$ dilute alloys have been measured for $H\sim 60 \mathrm{and} 30$ kG and $T<\mathrm{}20\mathrm{}$ K. The $\Delta K\left(T\right)\mathrm{}$ data confirm that the conduction-electron spin polarization scales with the impurity susceptibility and varies as $1-{\left(\frac{T}{17}\right)}^2$ for $T\ll T_{\mathrm{K}}$. A "Korringa" relation $T_{1}T{\left(\Delta K\right)}^2=\mathrm{const}$ is found, in agreement with recent calculations of the dynamic susceptibility.

Following the classical approach of Sauter, of Heisenberg and Euler and of Schwinger the process of vacuum polarization in the field of a "bare" Kerr-Newman geometry is studied. The value of the critical strength of the electromagnetic fields is given together with an analysis of the feedback of the discharge on the geometry. The relevance of this analysis for current astrophysical observations is mentioned.

We present high-temperature series through tenth order for the susceptibility of all classical scalar models with bilinear nearest-neighbor interactions in the absence of symmetry-breaking fields. As an example of the use of these results we examine the tricritical behavior of triple-well Landau-Wilson models which interpolate between the Blume-Capel and Riedel-Wegner models. The general series are given for the fcc, bcc, and simple cubic lattices.

The relation between the $s$-state Ashkin-Teller-Potts (ATP) model and the percolation problem given by Fortuin and Kasteleyn is used to formulate a renormalization-group treatment of the percolation problem. Both an $\epsilon$ expansion near 6 spatial dimensions and cluster approximations for the recursion relations of a triangular lattice are used. Series results for the ATP model are adapted to the percolation problem.

We present the results of gravitational radiation experiments with two 1400-kg antennas at ${\nu }_0=145\mathrm{}$ Hz. The square antennas, 1.65×1.65×0.19 ${\mathrm{m}}^3$, $Q_M\simeq 2.0\times {10}^5$, with electrostatic transducers of $\beta \simeq 1.8\times {10}^{-3\mathrm{}}$, have mean effective noise energy $\overline{D}\simeq 0.034k{T}_r$. The observed cross correlation of the outputs of the two detectors gives an upper limit for the relation between the mean energy spectrum density $F\left({\nu }_0\right)$ and the daily occurrence rate ${\dot{N}}_G$ of gravitational radiation pulses: $F\left({\nu }_0\right){{\dot{N}}_G}^{\frac{1}{2}}<~\left({3.6}_{-1.4\mathrm{}}^{+1.0\mathrm{}}\right)\times {10}^6$ J ${\mathrm{m}}^{-2\mathrm{}}$ ${\mathrm{Hz}}^{-1\mathrm{}}$ ${\mathrm{day}}^{-\mathrm{½}}$.

A model based on simple quark counting is presented, which describes the inclusive production of charged hadron pairs at large transverse momenta. Predictions are given for the ratios of cross sections for $p+{\mathrm{Be}}^9\to h_1+h_2+X$, where $h_1$ and $h_2$ are any of $p$, $\overline{p}$, ${\pi }^{+}$, ${\pi }^{-}$, $K^{+}$, and $K^{-}$. The essential feature of the model is that the valence quarks of the initial particles must be included in the counting.

In the leading-logarithm approximation, the high-energy fixed-angle elastic fermion-fermion amplitude and the asymptotic form factor have been calculated to sixth order for a Yang-Mills theory; some other processes have been calculated to fourth order. The results suggest properties of exponentiation and factorization which can be described in terms of momentum-dependent anomalous dimensions in the renormalization-group equations. We discuss the possible relation of the zero-mass limit of our results to particle confinement.

The order-${\alpha }^2{\left(Z\alpha \right)}^2$ vacuum-polarization correction for transition energies in muonic atoms is calculated in the static-muon, massless-electron limit. Conventional Feynman-parametric-integral techniques are utilized. The correction is found to be negligibly small, contrary to a previous claim appearing in the literature.

Okubo mass splitting is generalized to Han-Nambu color theory and used to predict a fourth $\psi$ particle with mass about 4.8 GeV/${\mathit{c}}^2$ and partial width into $e^{+}{e}^{-}$ of 0.8 keV.

The production of $\psi \mathrm{}\left(3.1\right)\mathrm{}$ mesons is reported for the reactions ${\pi }^{-}+\mathrm{Fe}\to {\mu }^{+}+{\mu }^{-}+\mathrm{anything}$, at 200 GeV, and $p+\mathrm{Fe}\to {\mu }^{+}+{\mu }^{-}+\mathrm{anything}$, at 240 GeV. For $\psi$ production, distributions in $x\equiv \frac{P_L}{P_{\mathrm{beam}}}$ and $P_{\perp }$ are given. For $x>~0.5$, the ratio of the $\psi$ production cross sections in iron for pions to that for protons is found to be 7.4±2.0.

The differential cross sections for coherent production of ${\overline{K}}^{*0\mathrm{}}\mathrm{}\left(890\right)\mathrm{}$ were measured with nuclear targets. These measurements are interpreted using a two-component model which accounts for Coulomb production and $\omega$ exchange. The radiative decay width is determined to be $\Gamma \left({\overline{K}}^{*0\mathrm{}}\mathrm{}\right(890)\mathrm{}\to {\overline{K}}^0\gamma )=75\mathrm{}\pm 35$ keV, which is 3 times lower than expected from a simple quark model.

By introducing charge asymmetry as a new dynamical collective coordinate in the asymmetric two-center shell model, the nuclear charge dispersion in the fission of ${}_{}{}^{236}{}_{}{}^{}\mathrm{U}$ is calculated without using any free parameter. The agreement between theory and experiment is quite good.

We perform second-order distorted-wave Born-approximation analyses of the ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}(p, t){}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ $2^{-}$ excitation. The experimental angular distribution can be well reproduced by the simultaneous consideration of ($p, t, t^{\prime }$), ($p, p^{\prime }, t$), and ($p, d, t$) processes and the last two processes are found to be comparably important. The phase relations in the nonorthogonal term are also discussed and it is shown that this term gives a negligibly small contribution to such unnatural-parity-state excitation processes.

Energy spectra of fragments with $6<~Z<~12$ produced by the interactions of 28-BeV protons with uranium and gold were measured at several angles with a $\left(\frac{\mathrm{dE}}{\mathrm{dX}}\right)-E$ counter telescope. The angular distributions exhibit broad peaks at ∼70° which tend to become more prominent with increasing fragment $Z$. The presence of these peaks may be evidence for the generation of nuclear shock waves.

It has been found that for certain excited atomic states, the dipole matrix element for the $l\to l+1\mathrm{}$ photoionization channel has two minima and the $l\to l-1\mathrm{}$ channel has a minimum as well. Results for Cs $5d$ photoionization showing these phenomena are presented.