The zero-field, two-point correlation function of an $n$-vector system in $d=4-\epsilon$ dimensions is calculated to order ${\epsilon }^2$ for $T>~T_c$. The scaling function is obtained as a closed, cutoff-independent integral. As $t=\frac{(T-T_c)}{T_c}\to 0$ at fixed wave vector $q$, the leading variation is ${{\hat{E}}_1}^{n,d}\mathrm{}\left(q\right)\mathrm{}{t}^{1-\alpha }+{{\hat{E}}_2}^{n,d}\mathrm{}\left(q\right)t$, where $\alpha$ is the specific-heat exponent; thence the maximum in the scattering above $T_c$ is located, in good agreement with high-$T$ series-expansion estimates.

The nonoscillatory parametric instability is observed when the "pump" frequency is near the lower-hybrid frequency. Strong heating of both the ions and electrons has also been measured.

The radial distribution function for amorphous InAs, determined by high-angle x-ray diffraction, is shown to be similar to that of amorphous Ge; thus, the structure of amorphous InAs might be well described by the continuous random-network structures proposed for amorphous Ge. The presence of the odd-membered rings in the random-network structures requires a large fraction (∼ 10%) of the bonds to be between like atoms. Small-angle scattering measurements indicate that amorphous InAs is homogeneous and contains very few voids.

Photoelectron energy spectra have been measured as a function of angle on a (110) face of GaAs at the photon energy 10.2 eV. Marked variations are observed with both polar and azimuthal angles. We discuss implications with regard to the electronic band structure.

A two-order-parameter model is presented for the effect of lattice disorder on the magnetic properties of a crystal. It takes into account the presence of defects in an open lattice and, among other things, predicts a first-order transition of the magnetization order parameter upon melting. It applies well to MnBi and is general enough to include different types of defects and interactions.

We report on a molecular-dynamics study of a two-dimensional model system which is expected to exhibit antiferrodistortive structural phase transitions. The estimated values for the critical exponents $\beta$ and $\gamma$ are close to those of the two-dimensional Ising model. The origin of a central peak in the dynamic form factor is attributed to the formation and the dynamics of clusters.

The absolute magnitudes and shapes of the cross sections of a number of ${}_{}{}^2{}_{}{}^{}\mathrm{H}$- and ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-induced quasifree scattering processes are correctly predicted by the use of Eckart cluster-model wave functions for the light nuclei involved and a simple, but physically plausible, modification of the Rogers-Saylor attenuation model.

An approximate angular-momentum dependence of the energy centroid and width of the distribution of shell-model states derived from the theory of continuous distributions is compared with the exact results obtained from the diagonalization of shell-model states. The agreement is found to be very good. A density of shell-model states as a function of energy and angular momentum is presented which should be valid for nuclei with a large number of valence particles.

Application of the Rogers-Saylor attenuation model in proton quasifree scattering on ${}_{}{}^2{}_{}{}^{}\mathrm{H}$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$, and ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ is able to reproduce the strong energy and target-mass dependence of the ratio of experimental data to plane-wave impulse-approximation calculations.

The first-order neutrino equations are shown to be separable in the Kerr-metric background. These equations are then used to show that the neutrino field is not superradiant, in contrast to the scalar, electromagnetic, and gravitational fields.

We present the first observations of quiet-time interplanetary protons in the energy range 38 to 334 keV from the Apollo 16 subsatellite. These proton fluxes vary by a factor of ∼ 5 over a six-month period. Their spectrum can be represented by a power law $\frac{\mathrm{dJ}}{\mathrm{dE}}=5.6\mathrm{}{E}^{-1.3\mathrm{}}$ ${\left({\mathrm{cm}}^2\mathrm{s}\mathrm{e}\mathrm{c}\mathrm{s}\mathrm{t}\mathrm{e}\mathrm{r}\mathrm{k}\mathrm{e}\mathrm{V}\right)}^{-1\mathrm{}}$ from 38 to 334 keV during May 1972.

Results are reported based on a study of 3114 ${\pi }^{-}p$ events at 205 GeV/c in the National Accelerator Laboratory 30-in. bubble chamber. The measured ${\pi }^{-}p$ total and elastic cross sections are 24.0 ± 0.5 and 3.0 ± 0.3 mb, respectively. The elastic differential cross section has a slope of 9.0 ± 0.7 ${\mathrm{GeV}}^{-2\mathrm{}}$ for $0.03\le -t\le 0.6$ ${\mathrm{GeV}}^2$. The average charged-particle multiplicity for the inelastic events is 8.02 ± 0.12.

SU(3) in particle reactions involving pseudoscalar mesons is discussed in the framework of chiral SU(3) ⊗ SU(3) charge algebra, partial conservation of axial-vector current, and asymptotic SU(3).

Close-coupling calculations of $e$-He scattering in the region 30-70 eV reveal structures in the $n=2\mathrm{}{}_{}{}^{1,3}{}_{}{}^{}S$ excitation cross sections between 30 and 50 eV, in agreement with recent experiments. The structures are attributed to open-channel compound-state formation. Additional structures are also predicted at both higher and lower energies. These calculations suggest that temporary negative-ion formation should be considered as a mechanism for triplet excitation.

The lifetimes of core hole states, as determined from x-ray photoemission measurements in a variety of materials, is shown to depend on, and in many cases be primarily determined by, an interatomic Auger mechanism involving transitions from ligand valence electrons. Interpretations of linewidths and other spectral features observed from those spectroscopies involving core holes must be re-evaluated in light of these processes.

The existence of the hybrid Penning reaction, ${\mathrm{He}}^{+}+X\to \mathrm{He}+X^{++}+e$, has been confirmed for thermal-energy collisions of ${\mathrm{He}}^{+}$ with Mg, Ca, Sr, Ba, Y, Ce, Yb, Sn, and Pb. A new two-electron Penning reaction, ${\mathrm{He}}^{*}+X\to \mathrm{He}+X^{++}+2e$, has been identified in $\mathrm{H}\mathrm{e}*$-Ce and $\mathrm{H}\mathrm{e}*$-Y collisions.

Analysis of experimental data for several metals is found consistent with the surface photoelectric theory of Mitchell and Makinson. Surface roughness is invoked to account for the observed angular dependence of photoelectric yields.

The generation of high-current (∼${10}^5$ A) pulsed ion beams with ion energy in the range 0.5-10 MeV appears to be possible by modifications of present electron-beam technology.

When ion sheet beams medulated at a prescribed frequency are injected into plasmas, ion acoustic waves are found to be excited nearly perpendicularly to the ion sheet beams. The amplitude and frequency of the ion acoustic waves can be controlled by changing the modulation amplitude and frequency of the ion beams. The exciting mechanism is qualitatively explained by a fluid model.

We report a series of measurements on the viscosity of liquids in the presence of thermal gradients. A relevant increase of viscosity is found when the gradient of $T$ is parallel to the gradient of the shear, no increase when they are mutually perpendicular. We suggest a possible connection between our measurements and recent theories of transport phenomena in liquids. The influence of the effect on measurements in critical systems is also briefly discussed.