Ion-Bernstein-wave heating is investigated in the JIPPT-II-U tokamak plasma, ${\overline{n}}_e\simeq 1.5\times {10}^{13}$ ${\mathrm{cm}}^{-3\mathrm{}}$, $T_{e0\mathrm{}}\simeq 700$ eV, and $T_{i0\mathrm{}}\simeq 300$ eV for $P_{\mathrm{rf}}\lesssim 100$ kW. When the $\frac{3}{2}{\Omega }_{\mathrm{H}}$ layer is placed near the plasma minor axis, the bulk-hydrogen-ion temperature shows a significant rise, $\Delta T_{i\perp }<~700$ eV and $\Delta T_{i\parallel }<~300$ eV. The ion-heating dependence on the magnetic field and rf power suggests a presence of a direct bulk-hydrogen heating mechanism at $\omega \simeq \frac{3}{2}{\Omega }_{\mathrm{H}}$.

The relativistic plasma wave excited when the frequency difference between two copropagating C${\mathrm{O}}_2$ laser beams equals the plasma frequency is detected for the first time. The plasma-wave frequency, wave number, spatial extent, and saturation time are directly measured by use of 7-mrad, collective, ruby Thomson scattering and the forward-scattered ir spectrum. The wave amplitude $\frac{\tilde{n}}{n_0}$ is inferred to be (1-3)% which gives a longitudinal electric field of 0.3 to 1 GV/m at a laser intensity of 1.7×${10}^{13}$ W/${\mathrm{cm}}^2$, in reasonable agreement with theory.

We report measurements of the temperature difference across layers of liquid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ mixtures in the superfluid phase as produced by a heat current at temperatures very close to $T_{\lambda }\mathrm{}\left(X\right)\mathrm{}$. Here $X$ is the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ molar concentration that covers the range $2\times {10}^{-9\mathrm{}}<X<\mathrm{}2\mathrm{}\times {10}^{-2\mathrm{}}$. The results are analyzed in terms of contributions from the boundary and the bulk fluid resistivities $R_K$ and ${\kappa }_{\mathrm{eff}}^{-1\mathrm{}}\mathrm{}\left(X\right)\mathrm{}$. Assuming $R_K\mathrm{}\left(X\right)\mathrm{}$ to be independent of $X$, we find that for $X<\mathrm{}{10}^{-3\mathrm{}}$ there is a systematic departure from the prediction ${\kappa }_{\mathrm{eff}}\propto X^{-1\mathrm{}}$. The thermal-relaxation times are consistent with this observation. An alternative analysis invoking an anomalous boundary resistance is presented.

A new set of renormalization equations for the two-dimensional Coulomb gas is derived. Within this new description, the prediction of a universal jump or the prediction that the exponent $\eta$ is ¼ at the critical line breaks down below a certain temperature. Consequently it should be possible to have a Kosterlitz-Thouless transition without a universal jump. A realization is suggested.

A strong asymmetry has been observed in the angular dependence of the catastrophic dechanneling depth in strained-layer superlattices. This new effect occurs under resonance conditions, where the wavelength of the planar-channeled particles equals the period of the superlattice, and is demonstrated for {110} planar channeling in $\mathrm{GaP}/\mathrm{Ga}{\mathrm{As}}_x{\mathrm{P}}_{1-x}$. A theoretical, phase-plane analysis shows that the angular tilt required for shifting of the catastrophic depth by one layer is a direct measure of the strain in the first few layers.

A new model of liquid-solid freezing, based on the orientational order in a three-dimensional liquid, is proposed. The novel aspect of the model is the inclusion of the coupling between the orientational and elastic degrees of freedom in a dense liquid. This allows for the explicit computation of several thermodynamic quantities of interest near the freezing transition.

The cleaved Ge(111)2×1 surface of a heavily $n$-doped crystal has been studied with angle-resolved photoemission. A new partly filled surface-state band is observed at the Fermi level, only appearing close to the $\overline{J}-\overline{K}$ line in the 2×1 surface Brillouin zone. The observed emission corresponds to the dispersion minimum of the antibonding band in the $\pi$-bonded chain model. The direct band gap between the surface-state bands is found to be 0.5 eV, in good agreement with results from absorption measurements.

Two-dimensional plasmons have been investigated in AlGaAs-GaAs heterostructures with transmission spectroscopy. In a magnetic field $B$, we observe an interaction of the plasmon excitation with harmonics of the cyclotron-resonance frequency ${\omega }_c=\frac{\mathrm{eB}}{m}$, which arises from nonlocal effects on the two-dimensional-plasmon excitation and is governed by the parameter ${\left(\frac{q{v}_{\mathrm{F}}}{{\omega }_c}\right)}^2$ ($q$ is the plasmon wave vector; $v_{\mathrm{F}}$ is the Fermi velocity). The dispersion and the excitation strengths of the combined resonances are in excellent quantitative agreement with a quasiclassical nonlocal theory.

Interface compound formation at Cu-In films is studied with the perturbed $\gamma -\gamma$ angular correlation method using radioactive ${}_{}{}^{111}{}_{}{}^{}\mathrm{In}$ probe atoms. The growth of a Cu${\mathrm{In}}_2$ intermetallic interface phase is observed with a sensitivity on the scale of atomic distances in the temperature range between 220 and 340 K. This new phase is characterized by an electric field gradient (at $T=77\mathrm{}$ K) with $V_{\mathrm{zz}}=4.50\mathrm{}\left(5\right)\mathrm{}\times {10}^{17}$ V/${\mathrm{cm}}^2$ and $\eta =0.57\mathrm{}\left(1\right)\mathrm{}$. The activation energy of phase formation for Cu${\mathrm{In}}_2$ was determined to be 0.42(2) eV.

Superconductivity in the simple hexagonal phase of silicon is predicted on the basis of an electron-phonon-coupling calculation and measured experimentally up to a pressure of 25 GPa in a Bridgman-type opposed-anvil device. The highest measured superconducting transition temperature is 8.2 K at 15 GPa for the simple hexagonal phase.

It is shown that the entropy of a rotating, charged black hole is, in senses made precise in the paper, (i) the logarithm of the number of quantum mechanically distinct ways that the hole could have been made, and (ii) the logarithm of the number of configurations that the hole's "atmosphere," as measured by stationary observers, could assume in the presence of its background noise of acceleration radiation. In addition, a proof is given of the generalized second law of thermodynamics.

We display a model for the up- and down-quark mass matrices which permits, for any number of generations, the complete determination of the Kobayashi-Maskawa matrix in terms of the quark masses. We discuss in this framework the correlation between the quark-mass spectrum and a maximal $\mathrm{CP}$-nonconserving phase and also give an application to the four-generation case.

We have measured the differential cross section for $\overline{p}p$ and $\mathrm{pp}$ elastic scattering at $\sqrt{s}=53\mathrm{}$ GeV in the interval $0.5<\mathrm{}\left|t\right|<4.0\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ at the CERN intersecting storage rings using the split-field magnet detector. The shape of the differential cross section differs significantly between $\overline{p}p$ and $\mathrm{pp}$ scattering in the region $1.1<\mathrm{}\left|t\right|<1.5\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$, with $\overline{p}p$ data showing a less pronounced dip structure than $\mathrm{pp}$ data.

Supersymmetric quantum mechanics is formulated for spherically symmetric potentials in $N$ spatial dimensions. It is seen that the supersymmetric partner potential of a given potential can be effectively treated as being in $N+2\mathrm{}$ dimensions. This fact is exploited in calculations using the shifted $\frac{1}{N}$ expansion. Also, the violation of the no-degeneracy theorem in one dimension by the Coulomb potential is seen as a consequence of this result.

The Gaussian variational approximation is used to calculate the two-particle bound-state binding energy and wave function in the model: $\lambda ({\phi }^6-{\phi }^4)$: in 1 + 1 dimensions. An analytic result is compared to the perturbative calculation of Dimock and Eckmann and to the numerical, lattice work of Barnes and Daniell.

We show that the Wilson renormalization-group flow of effective Lagrangians in fermionic models can be explicitly controlled using convergent perturbation expansions. A simple rigorous construction of two-dimensional asymptotically free field theories (the Gross-Neveu models) results.

The inclusive photon spectrum in hadronic decays of the $\Upsilon \mathrm{}\left(2S\right)\mathrm{}$ is measured with the Crystal Ball detector at DORIS II. Four well separated photon lines, which are consistent with the decay hypothesis $\Upsilon \mathrm{}\left(2S\right)\mathrm{}\to \gamma +{}_{}{}^3{}_{}{}^{}P_{2,1,0}^{}{}_{}{}^{}$ and ${}_{}{}^3{}_{}{}^{}P_{2,1}^{}{}_{}{}^{}\to \gamma \Upsilon \mathrm{}\left(1S\right)\mathrm{}$, are observed. The energies of the lines from the primary transitions are $E_{\gamma 1}=110.4\mathrm{}\pm 0.8\pm 2.2$ MeV, $E_{\gamma 2}=130.6\mathrm{}\pm 0.8\pm 2.4$ MeV, and $E_{\gamma 3}=163.8\mathrm{}\pm 1.6\pm 2.7$ MeV; the branching fractions are (5.8±0.7±1.0)%, (6.5±0.7±1.2)%, and (3.6±0.8±0.9)%, respectively. The secondary transitions center at $〈E_{\gamma }〉\simeq 430$ MeV with a combined branching fraction of (3.6±0.7±0.5)%.

Theories of family unification predict four left-handed and four right-handed families of quarks and leptons, all with masses below 265 GeV. The lightest mirror quark has a mass of less than 140 GeV. All charged leptons are lighter than 55 GeV, and the lightest is below 40 GeV. All five new neutrinos have masses less than 40 GeV and contribute to the width of the $Z^0$. We study the decays of these new families, and discuss rare processes such as $\mu \to e\gamma$. We also examine proton decay, and show that it can proceed into $e^{+}{\pi }^0$ at the observable but acceptable rate of ${10}^{32\pm 1}$ yr.

The supersymmetric contributions to the $K_L-K_S$ mass difference makes the previously obtained bounds on the right-handed scale ($M_R>1.6\mathrm{}$ TeV) much weaker. This raises the interesting possibility that the left-right model could be tested as an alternative to $\mathrm{S}{\mathrm{U}}_L\mathrm{}\left(2\right)\mathrm{}\otimes \mathrm{U}\mathrm{}\left(1\right)\mathrm{}$ at low energies. Also we find that to demand that the supersymmetric contribution to the $K_L-K_S$ mass difference be less than 3.5×${10}^{-15\mathrm{}}$ GeV requires that scalar-quark masses be more than 400 GeV.

Traditional nonrelativistic impulse-approximation treatments of $p$-nucleus scattering using a local nucleon-nucleon $t$ matrix neglect nuclear currents which are intrinsic to relativistic approaches also employing a local $t$ matrix. Inclusion of these current terms is essential to the understanding of the spin-difference function, $(D_{\mathrm{qk}}+D_{\mathrm{kq}})+i(P-Ay)\mathrm{}$, as shown by comparison with ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(p, p^{\prime }){}_{}{}^{12}{}_{}{}^{}\mathrm{C}_{}^{*}{}_{}{}^{}(12.71\mathrm{} \mathrm{MeV}, 1^{+}, T=0)$ spin-difference data at 150 MeV.