Optical interferometry was used to measure surface profiles of He II. Depressions observed following rapid container spinup agreed with theoretical profiles of a superfluid vortex with circulation $\approx \frac{400h}{m}$.

The results of an augmented-plane-wave calculation of the electron and positron density distributions in a vacancy in A1 are reported. The environment of the vacancy was simulated by a super cell with a volume 27 times that of the primitive unit cell. These results show that jellium-model calculations overestimate the electron density in a vacancy. The variation of the positron lifetime associated with thermal expansion of the lattice is also presented.

The four independent symmetry components of first-order phonon Raman scattering in the paramagnetic phase of europium chalcogenides have been measured around the fundamental gap. The usually unobservable antisymmetric ${{\Gamma }_{15}}^{+}$ component is found to be the largest one. The resonance enhancements of the different components, their relative intensities, and the scattered spectra are explained by a parameter-free microscopic theory which takes into account the spin disorder of the ${\mathrm{Eu}}^{2+}$ ions and the spin-orbit interaction of the $4f$ electrons.

Photoionization of an electron trap in vitreous Si${\mathrm{O}}_2$ films was measured between 6 and 300 K. The photoionization threshold decreased monotonically with increasing temperature and film thickness. A thermal broadening of the ionizing transition was proportional to ${coth}^{\frac{1}{2}}\left(\frac{\tau }{2T}\right)$ where $\tau =129\mathrm{}$ K and $T$ is temperature in kelvins. These characteristics of the photoionization response were similar to those reported for color-center optical absorptions in single crystals, and were related to static and dynamical strains in the oxide film.

The behavior of the effective bulk conductivity ${\sigma }_e$ and of the effective bulk dielectric constant ${\epsilon }_e$ of a heterogeneous mixture of a conducting phase and an insulating dielectric phase is analyzed in the vicinity of the percolation threshold. Exact considerations of a general nature lead to the conclusion that ${\epsilon }_e$ diverges as the conductivity threshold is approached from either side. The introduction of a homogeneity or scaling hypothesis leads to relations between the critical behavior of ${\sigma }_e$ and ${\epsilon }_e$.

Simultaneous low-energy electron diffraction (LEED) and electron-spin polarization measurements have been made on clean W(001) for the first time at a high angle of incidence (47.5°) with a surface azimuth of 50°. Polarization peaks ranging from + 15% to - 27% have been observed and occur at energies where the LEED intensities are close to a minimum. After a cleaning flash, effects ascribed to specimen cooling caused changes with time in LEED intensities but not in spin polarization. Reasons are discussed.

X-ray photoemission (XPS) measurements of wustite, ${\mathrm{Fe}}_x\mathrm{O}$ ($x=0.90-0.95\mathrm{}$), show that the Fe ($3d$) valence-band final states spread ∼10 eV below $E_{\mathrm{F}}$. This is much broader than previous claims based on the analysis of lower-energy (5-90 eV) photoemission spectra. Crystal-field-theory results, based on ab initio calculations, are consistent with the broader spectrum. Configuration interaction is found to have important consequences for the position and intensity of the XPS peaks.

Measurements of the optical absorption spectrum corresponding to the ${}_{}{}^5{}_{}{}^{}T_{2\mathrm{g}}^{}{}_{}{}^{}\to {}_{}{}^5{}_{}{}^{}E_{\mathrm{g}}^{}{}_{}{}^{}$ transition of ${\mathrm{Fe}}^{2+}$ in MgO determine the principal parameters characterizing a dynamic Jahn-Teller (JT) effect in the excited ${}_{}{}^5{}_{}{}^{}E_{\mathrm{g}}^{}{}_{}{}^{}$ state, including the JT energy $E_{\mathrm{JT}}\cong 1300$ ${\mathrm{cm}}^{-1\mathrm{}}$ and tunneling splitting $3\Gamma =14\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$. These results provide a successful test of the vibronic model for an $E$-state JT ion.

We present the gauge theory of the graded conformal group. It contains four real fields with spins 2, $\frac{3}{2}$, 1, and ½. The theory is invariant under local proper conformal, scale, chiral, gravitational, and supersymmetry transformations. This is the first of a class of superunified field theories, possessing $\mathrm{U}\mathrm{}\left(n\right)\mathrm{}$ rather than $\mathrm{O}\mathrm{}\left(n\right)\mathrm{}$ internal gauge symmetries and without a cosmological constant. Unitarity, renormalizability, and asymptotic states and the cancellation of some complicated higher-order terms in one of the two supersymmetry variations remain to be investigated.

Using two large NaI detectors, a limit on the branching ratio for the ${\mu }^{+}\to e^{+}\gamma$ decay has been found to be $R_{\mu e\gamma }=\frac{\Gamma ({\mu }^{+}\to e^{+}\gamma )}{\Gamma ({\mu }^{+}\to e^{+}{\nu }_e{\overline{\nu }}_{\mu })}<3.6\mathrm{}\times {10}^{-9\mathrm{}}$ at a 90% confidence level.

We argue that the sea of virtual quark-antiquark pairs in a proton is polarized. Quantum chromodynamics allows a valence quark to emit a gluon which then produces pairs. If the parent quark in this process exhibits a ${\mathrm{}(1-x)\mathrm{}}^3$ behavior as $x\to 1$ then the antiquark with helicity the same as the original quark will have a leading ${\mathrm{}(1-x)\mathrm{}}^5$ distribution. Implications for the counting rules and for polarized Drell-Yan annihilation are discussed.

We consider a quark-parton model in which wee partons of the projectile interact with wee partons of essentially independent nucleons in the nuclear target. The ratio of multiplicities in the central region is $\frac{{〈n〉}_{\mathrm{HA}}}{{〈n〉}_{\mathrm{HN}}}=\frac{1}{2}\overline{\nu }+\frac{\overline{\nu }}{(\overline{\nu }+1)}$, where $\overline{\nu }$ is the mean number of inelastic collisions of the projectile $H$, in agreement with experiment. We also predict nucleus-nucleus multiplicities, the multiplicity distribution, and the absence of shadowing in large-$q^2$ and large-$p_T$ reactions.

This work examines the quark-loop contributions in the renormalizable SU(3) $\sigma$ model. Radiative meson-decay rates are found to be in good agreement with experiments. The quark-loop contribution is shown to dominate the vector form factor and, in the Padé approximation, the vector form factor exhibits the picture of vector dominance. To this order of approximation, the closeness between the calculated and the known values of $m_{\rho }$, $m_{\omega }$, $m_{\varphi }$, and ${\Gamma }_{\rho }$ provides further evidence that quarks have three colors.

Anomalies in the experimental spectra for the positive-parity states of the Pt and Hg isotopes are explained in the $\gamma$-deformed-rotor model which takes into account the coupling of the two quasiparticle excitations with the ground band. It is found that the 0-2-quasiparticle coupling is very important. Moreover, it is recognized that the linear increase in the moment of inertia with the square of the angular velocity can be described by this coupling.

Energy and angular distributions of photopions from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, leading to low-lying residual states in ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$, have been measured via the ($e, e^{\prime }{\pi }^{+}$) reaction at $E_e=195\mathrm{}$ MeV. The shape of the patterns agrees with the theoretical estimates deduced from other electron scattering data and also with shell-model calculations. A comparison of the absolute value shows the importance of correct estimation of the pion wave. The result demonstrates that photopion experiments can provide a promising method for studying spin-flip-type electromagnetic transitions in nuclei.

Three resonances in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ + ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ with $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}\left(J^{\pi }\right)$ of 8.85($6^{+}$), 11.2($8^{+}$), and 13.75(${10}^{+}$) are reported. Together with earlier data, these resonances fit in a rotational band in ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$. A model based on the rotation-vibration coupling is proposed to account for these data.

With intense light of a pulsed tunable dye laser, the ${}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$ resonance state of xenon and the $P$, $Q$, and $R$ branches of the (2-0) band of CO in the fourth positive system ($A{}_{}{}^1{}_{}{}^{}\Pi \leftarrow X{}_{}{}^1{}_{}{}^{}\Sigma _{}^{+}{}_{}{}^{}$) are excited by simultaneous absorption of three visible laser photons. The excitation is monitored by detecting the fluorescent decay in the vacuum ultraviolet.

The dc resistivity caused by ion acoustic turbulence in plasmas is measured and effective collision frequencies of electrons are obtained from the resistivity as a function of electron drift velocity. These experimental results can be explained by using the theoretical model of Horton et al., in which the nonlinear ion Landau damping dominates the turbulence spectrum.

Density profile of the glass-microballoon plasma irradiated by Nd laser with intensity of ${10}^{16}$ W/${\mathrm{cm}}^2$ was measured by newly developed microscopic interferography. The existence of strong density modification by intense radiation pressure was clearly indicated.

Analytic results are obtained for generation of solitons and their effects on density-profile modifications at critical density for resonance absorption process.