We have measured the heat capacity of granular aluminum specimens with normal-state resistivities ${\rho }_N$ between 0.6×${10}^{-3\mathrm{}}$ and 40 × ${10}^{-3\mathrm{}}$ Ω cm. The specimens become superconducting with a heat-capacity transition which is BCS-like for the lowest ${\rho }_N$, and then diminishes until it is no longer observable for the highest ${\rho }_N$. We conclude that the grains become decoupled such that, because of their small size, they do not exhibit bulk superconductivity when they are isolated.

Free-carrier absorption of tuned C${\mathrm{O}}_2$-laser radiation is shown to be a valuable new tool for the extraction of information on photoheated hot carriers and the free-carrier absorption coefficients in low-concentration, degenerate $n$-InSb at liquid helium temperatures. The technique exploits parallel photoheating and dc-heating experiments conducted in a regime where conductivity changes are unambiguously determined by mobility changes.

The surface electronic structure of a stepped Cu(211) crystal was elucidated by angle-resolved photoemission spectroscopy. A surface state was found on the three-atom terraces, indicating that the terrace surface potential resembles that of a Cu(111) crystal surface. The $d$-band dispersion relations of Cu(211) were also found to resemble bulk copper closely. The observed enhanced reactivity of the stepped surface does not appear to arise from gross changes in the surface electronic structure.

We present a theoretical study of the electron-hole drop containing both "hot" and "cold" carriers in $〈111〉$-stressed Ge at $T=0\mathrm{}$. We predict that for certain values of the stress this system phase separates into two degenerate Fermi liquids, one containing "cold" and the other containing both "hot" and "cold" electrons. It should be possible to verify this prediction experimentally.

We report the first observation of magnetothermal quantum oscillations in ${\mathrm{C}}_{12n}\left(\mathrm{Sb}{\mathrm{Cl}}_5\right)$ for $n=2\mathrm{}$ and $n=4\mathrm{}$. We interpret these results assuming that the compound is composed of two phases: pure graphite and intercalated sandwiches which behave like two-dimensional metals. This model explains simultaneously the metallic reflectivity and conductivity and the immeasurably small Hall coefficient observed in these compounds.

Energy distribution measurements of field-emitted electrons reveal a free-electron-type behavior for clean Ir(100) and (110) surfaces. Adsorption of CO on Ir(100) causes the appearance of a structure at 0.6 eV below the Fermi level $E_{\mathrm{F}}$ which is identified with a chemisorption level created by "back donation" of metallic $d$ electrons into the CO $2{\pi }^{*}$ level. Adsorption of atomic oxygen on Ir(100) and (110) leads to the formation of a maximum at 1.0 eV below $E_{\mathrm{F}}$ which is ascribed to a state derived from one of the O $2p$ levels.

The magnetization density, $M$, of a CuNi thin film containing a 30-Å composition modulation has been deduced from ferromagnetic resonance data between 120 and 325°K. The data imply the existence of high-$M$ regions in the modulated film. At 300°K, $M$ is about 200 emu/${\mathrm{cm}}^3$, and increases as the temperature decreases. By 125°K, $M$ is significantly larger than that of pure Ni. After most of the modulation was annealed out, $M$ had decreased by an order of magnitude.

We report on calculations of the electronic states in disordered ${\mathrm{Cu}}_c{\mathrm{Ni}}_{\mathrm{}(1-c)\mathrm{}}$ alloys based on a complete solution of the coherent-potential approximation for a muffin-tin model of the alloy potential [Korringa-Kohn-Rostoker coherent-potential-approximation (KKR-CPA)]. The computational effort required is modest on the scale of that involved in bandstructure calculations for many atoms per unit cell. The calculated densities of states are in good agreement with the results of photoemission and other experiments. The adequacy of previous approximate KKR-CPA and averaged $t$-matrix calculations is discussed.

Neutron inelastic scattering techniques have been used to examine the dispersion relations for magnetic excitons propagating on the hexagonal sites of double-hcp Pr when uniaxial stress is applied along the $\left[1\mathrm{}\overline{2}10\right]$ direction. The mode of lowest energy (longitudinal optic) along $\Gamma M$ was found to exhibit a clear soft-mode behavior with increasing stress. Elastic satellite reflections corresponding to long-range magnetic ordering in a longitudinally modulated structure were observed: at 800 bars the Néel temperature is 7.5 K.

The electronic structure of a platinum/electrolyte interface is determined by photoelectrochemical measurement of optical absorption processes. Photoemission into the electrolyte shows the electrode surface to be metallic at cathodic potential while thin semiconducting oxide layers are observed at anodic potentials. Internal photoemission at the metal/oxide interface indicates the Fermi level to be at midgap for the oxide which has a band gap of 3.1 eV.

A simple proof is given of a general result which shows how to construct solutions of a coupled system of linear self-adjoint partial differential equations once one has succeeded in deriving a decoupled equation in the manner described below. In the case of electromagnetic and gravitational perturbations of algebraically special vacuum space-times, this procedure yields the formulas of Cohen and Kegeles and of Chrzanowski.

We define coherent states for general potentials, requiring that they have the physically interesting properties of the harmonic-oscillator coherent states. We exhibit these states for several solvable examples and show that they obey a quantum approximation to the classical motion.

Recently, anomalous production of dimuons with $m<\mathrm{}100\mathrm{}$ MeV has been reported in 16-GeV/c ${\pi }^{\pm }p$ collisions. Production and subsequent decay of the tensor mesons $f$ and ${A_2}^0$ is suggested as a source for these dimuons.

Muon-neutrino and -antineutrino scattering off electrons was detected in a 19-ton Al spark chamber, exposed to the wide-band $\nu$ ($\overline{\nu }$) beam from the CERN proton synchrotron. The background was determined experimentally. 11 (10) genuine ${\nu }_{{\mu }^{-}}$ (${\overline{\nu }}_{{\mu }^{-}}$) $e$ scattering events were found. The respective cross sections are $(1.1\mathrm{}\pm 0.6)\times {10}^{-42\mathrm{}}(E_{\nu }/\mathrm{GeV})$ ${\mathrm{cm}}^2$ and $(2.2\mathrm{}\pm 1.0)\times {10}^{-42\mathrm{}}(E_{\nu }/\mathrm{GeV})$ ${\mathrm{cm}}^2$. The analysis excludes a pure $V-A$ interaction, and makes a pure $V$ or $A$ theory improbable. The data agree well with the Salam-Weinberg model and ${{sin}^2\theta }_{\mathrm{W}}=0.35\mathrm{}\pm 0.08$.

Proton-proton and proton-deuteron elastic scattering has been measured for incident laboratory energy from 50 to 400 GeV; minimum $\mathrm{}\left|t\right|\mathrm{}$ values were, for $p-p$, 0.0005 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$, and for $p-d$, 0.0008 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. From the differential cross sections we have determined the ratios of the real to imaginary parts of the forward scattering amplitude, ${\rho }_{\mathrm{pp}}$ and ${\rho }_{\mathrm{pd}}$, for $p-p$ and $p-d$ scattering. Using a Glauber approach and a sum-of-exponentials form factor we obtain ${\rho }_{\mathrm{pn}}$ for $p-n$ scattering.

I point out that the structural property of two-dimensional perturbation theory, which allows the existence of nontrivial, factorizing $S$ matrices, has an analogy in higher dimensions.

I have analyzed pion-nucleon elastic scattering data from 1.6 GeV/c up to 10 GeV/c. The analysis makes use of a physical impact-parameter picture as an intermediate step. Many of the resulting partial-wave amplitudes show structure in their Argand plots. These are discussed in terms of possible high-spin resonances.

A CCBA (coupled-channels Born approximation) analysis is used to study the importance of multistep processes involving quadrupole inelastic excitations in producing anomalously shaped angular distributions for rare-earth ($d$,$t$) transitions. The CCBA results are compatible with DWBA (distorted-Wave Born approximation) results in the cases where the DWBA works well and tend to improve agreement for the anomalous transitions —but the overall agreement is still rather poor and additional improvements in the reaction calculations will be needed to understand the anomalous transitions.

An intense laser and a probe laser in near resonance with the sodium $3S_{\frac{1}{2}}\to 3P_{\frac{1}{2}}$ and $3P_{\frac{1}{2}}\to 4D_{\frac{3}{2}}$ transitions, respectively, produce a three-photon ionization current used to study the broadening and Rabi splitting of the $3P_{\frac{1}{2}}$ intermediate state as a function of probe-laser tuning. We find a narrow, intense-laser detuning region where the peak-heights ratio of the Rabi-split $3P_{\frac{1}{2}}$ doublet is reversed from that predicted for a monochromatic laser field. This is attributed to the finite (∼ GHz) laser linewidth.

An assemblage of < 50 ${\mathrm{Ba}}^{+}$ ions, contained in a parabolic well, has been visually observed and cooled by means of near-resonant laser irradiation.