NMR studies of ${}_{}{}^{95}{}_{}{}^{}\mathrm{Mo}$ show that the enhancement of $H_{c_2}$ (∼ 100 kG) in Eu-substituted Sn${\mathrm{Mo}}_6$${\mathrm{S}}_8$ arises from a negative $s$-band spin polarization at the Mo site. Mössbauer-effect studies of ${}_{}{}^{151}{}_{}{}^{}\mathrm{Eu}$ indicate a small positive polarization at the Eu site and a weak Korringa relaxation, which is consistent with the weak depression of $T_c$. The ${\mathrm{Eu}}^{2+}$ isomer shift (-14.0 mm/sec) shows an extremely low $s$-electron density at the rare-earth site.

We report unusual structure in the dc conductivity below 4.2 K as well as nonperiodic oscillations in the magnetoconductance of a two-dimensional electron gas in Si at low magnetic fields. A model of a superlattice with a gap which varies with carrier density is proposed to interpret the results. The superlattice appears to be of a somewhat general nature although the cause is not yet known.

We report the first direct measurement of velocity distributions of electron-hole drops, and discuss them in relation to existing theoretical models. The data, obtained by frequency analysis of scattered light, show acceleration near the surface, while at larger depths, the drops appear to experience viscous deceleration with a relaxation time of ${10}^{-4\mathrm{}}$ sec. We find difficulties in reconciling the data with the present ideas of forces resulting from excitons, phonons, or mutual repulsion.

The hypothesis of the first observed heavy antinucleus is proposed for the event of Price et al. This hypothesis demands depletion of the high-energy knock-on electrons, which should be clearly evident in the nuclear emulsion. This hypothesis does not directly contradict any previous antimatter search; and conflict with extrapolations from previous searches is of small statistical significance.

The spectrum of the mass operator on the soliton sectors of the ${\left[\lambda {\left(\overrightarrow{\varphi }·\overrightarrow{\varphi }\right)}^2\right]}_2$ theory with explicitly broken $\mathrm{O}\mathrm{}\left(N\right)\mathrm{}$ invariance ($N>~1$) in the two-phase region is studied. It is shown rigorously that, for small $\lambda >0\mathrm{}$, the mass gap $m_s$ is positive and $m_s\equiv m_s\left(\lambda \right)\sim {\lambda }^{-1\mathrm{}}$, as $\lambda \to 0^{+}$. It is argued that $m_s$ is separated from the rest of the mass spectrum by an upper gap, so that the soliton is a stable particle. Our methods apply to other models with spontaneously broken, discrete symmetries.

We consider the possibility that muon-number conservation is not a fundamental symmetry of nature. In simple SU(2) ⊗ U(1) gauge theories with several scalar boson doublets, muon number will still atuomatically be conserved by the intermediate-vector-boson interactions, but not by effects of virtual scalar bosons. The branching ratio for $\mu \to e+\gamma$ is estimated to be of order ${\left(\frac{\alpha }{\pi }\right)}^3$. Other $\mu -e$ transition processes are also discussed.

We consider the contribution of charmed quarks to vacuum polarization and to $\gamma \gamma$ scattering. In quantum chromodynamics the calculation is reliable for small photon momenta provided that the quark mass $m_c$ is large compared with the scale of the hadronic mass $\mu$, $4{m_c}^2\gg {\mu }^2$. By the use of dispersion relations, the calculation is converted into a set of sum rules which impose model-independent upper bounds on the charmonium leptonic and photonic decay rates and enables one to estimate the hadronic widths as well. Weak leptonic decays of the charmed mesons are also estimated.

With use of SU(4) as a spectrum-generating group, the radiative decay rates of the charmed vector mesons and of $J\left(\psi \right)$ are calculated. With the known decay rates of the "old" mesons $\Gamma (\omega \to \pi \gamma )$, $\Gamma (\varphi \to \eta \gamma )$, $\Gamma (\rho \to \pi \gamma )$, and $\Gamma (K^{0*}\to K^0\gamma )$ as input, one obtains $\Gamma (K^{+*}\to K^{+}\gamma )=2.6\mathrm{}$ keV, $\Gamma (\omega \to \eta \gamma )=220\mathrm{}$ eV, $\Gamma (\rho \to \eta \gamma )=4.8\mathrm{}$ keV, $\Gamma (\psi \to \chi \gamma )=1.6\mathrm{}$ keV, $\Gamma (D^{0*}\to D^0\gamma )=350\mathrm{}$ eV, and $\Gamma (D^{+*}\to D^{+}\gamma )=22\mathrm{}$ eV.

Cross sections for diffractive $\rho$ muoproduction in hydrogen are presented for $90 \mathrm{GeV}<\nu <135\mathrm{} \mathrm{GeV}$ (where $\nu$ is the energy lost by the scattered muon) and $Q^2<5\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. The results are compared with lower-energy data and the predictions of simple vector-dominance models.

The meson spectrum is studied with use of an equal-time relativistic two-body equation with electrostatic confinement potentials. A normalizability condition excludes all but a bag solution which gives a spectral pattern in between the SU(6) and the chiral SU(3) ⊗ SU(3) limits. Orbital mixing creates a pair of ${}_{}{}^3{}_{}{}^{}S_1^{}{}_{}{}^{}+{}_{}{}^3{}_{}{}^{}D_1^{}{}_{}{}^{}$ states sandwiching the ${}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}$ level. $\rho -{\rho }^{\prime }$ and $\frac{\psi }{J}-{\psi }^{\prime }$ pairs fit this picture very well.

A thermodynamic model, constructed in the framework of the big-bang equilibrium model, is proposed and used to study the spectra of high-energy composite particles that can be seen in relativistic heavy-ion collisions. Properties of the spectra are related to properties of the thermodynamic equilibrium region.

It is rigorously demonstrated that the nonrelativistic ${\mathrm{H}}^{-}$ ion has only one bound state in the fixed (infinite-mass) nucleus approximation with Coulomb interactions only.

We show that, by measuring the interference between quadrupole and dc-field-induced sum-frequency generation, both the magnitude and the sign of a quadrupole matrix element can be obtained relative to the dipole matrix elements in atomic transitions. We use the measurement of $〈3s\left|z^2\right|4d〉$ of sodium to demonstrate the technique.

The ratio of fluorescence intensities of the boron 2089- and 2498-Å lines is shown to depend on rare-gas pressure fo both xenon and krypton. This is interpreted as evidence of rare-gas quenching of the boron resonance radiation.

Anomalously rapid thermal transport from a skin layer to the plasma core has been observed in a toroidal turbulent heating experiment. The thermal transport rate is approximately two orders of magnitude faster than the classical rate based on the anomalous electron collision frequency.

Pseudopotential calculations for the pressure dependence of the dielectric constants and energy-band structure of trigonal Se are presented. The calculations explain recent experimental observations of a strong pressure dependence for the optic spectra of Se. It is shown that interchain interactions and not local-field corrections are most important in describing the pressure data.

The pressure dependence of the density of states and the reflectivity of trigonal Se is calculated using a new self-consistent pseudopotential technique. The results show that pressure-dependent reflectivity experiments may be interpreted without the need for microscopic fields.

The electron spin polarization of field-emitted electrons from atomically clean, field-evaporated in ultrahigh vacuum, single-crystal Ni tips has been measured with the probe hole selecting emission from the high-work-function (100) plane. We find $P=(-3.0\mathrm{}\pm 1)\%$ (magnetic moment antiparallel to the magnetization of the crystal). From an analysis of these and recent photoemission data we conclude that the magnetic (and electronic) properties of the surface and bulk Ni must be very similar.

Two high-energy neutrino events with three muons in the final state are presented. Some examples of possible origins are also discussed.

In a large-acceptance spectrometer at Fermilab, we have searched for multimuon events produced in collisions of 225-GeV/c protons and ${\pi }^{\pm }$ mesons with nuclei. In particular, additional muons accompanying the $\frac{J}{\psi }\to \mu \mu$ decay could signal charmed-particle production. For all data combined, the 90%-confidence limit on charmed-particle production in association with the $\frac{J}{\psi }$ is $\frac{{\sigma }_{\mathrm{JC}\overline{C}}}{{\sigma }_J}<0.01\mathrm{}$; the limit on production of $\frac{J}{\psi }$ pairs is $\frac{{\sigma }_{\mathrm{JJ}}}{{\sigma }_J}<0.021\mathrm{}$. Limits are also given for each beam particle separately.