The experiment on chaos in surface waves reported by Ciliberto and Gollub is used as a case model for an understanding of the appearance of few-dimensional chaos in systems with an infinite number of degrees of freedom. Center-manifold and normal-form theories are utilized to derive the pertinent dynamical system and to provide an approximate solution of the partial differential equations. Comparisons of theory and experiment are discussed.

A Higgs boson in the mass range 400-1000 GeV would be observable at the Superconducting Super Collider through its decay into two $Z\text{'}\mathrm{s}$, one of which decays into $e^{+}{e}^{-} or {\mu }^{+}{\mu }^{-}$ and the other into $\nu \overline{\nu }$. A comparison with the background from continuum $Z$ pairs shows that the signal would be apparent in the transverse-mass spectrum. The increase in statistics provided by these decays substantially extends the reach of the Superconducting Super Collider for discovering the Higgs boson.

We find a spherically symmetric solution to the gauged ${\mathrm{SU}\mathrm{}\left(2\right)\mathrm{}}_L\otimes {\mathrm{SU}\mathrm{}\left(2\right)\mathrm{}}_R$ chiral model. It corresponds to a new classical solution to the Weinberg-Salam model in the limit of infinite self-coupling and ${sin}^2{\theta }_{\mathrm{W}}=0\mathrm{}$. It has an energy of 11.6 TeV and is classically unstable under small perturbations of the fields. Quantum corrections may stabilize the solution via the introduction of higher-order terms in the effective action. We then investigate the solutions when a particular choice of a correction, the Skyrme term, is added to the Lagrangean. The energies of the (presumably) classically stable solutions are in the teraelectronvolt region.

We propose a scale-invariant hypercolor model with a nontrivial ultraviolet fixed point having large anomalous dimension, which resolves the notorious flavor-changing neutral-current problem in hypercolor models, and at the same time predicts a $J^{\mathrm{PC}}=0^{++}$ Nambu-Goldstone boson (dilaton) associated with the spontaneous breakdown of the scale invariance.

A severe constraint can be set on the mass and coupling of a photonlike particle that couples to hypercharge. The experimental upper limit on the decay branching ratio for $K^{+}\to {\pi }^{+} +$ "missing" requires that the coupling $\frac{f^2}{4\pi }$ be significantly smaller than ${10}^{-43\mathrm{}}$ for $m_{{\gamma }^{\prime }}={10}^{-9\mathrm{}}$ eV. This rules out the speculation made on the basis of a recent reanalysis of the Eötvös experiment.

We discuss experiments for detecting hyperphotons (${\gamma }_Y$), which are the real quanta of a hypercharge field whose existence has been suggested by a recent reanalysis of the Eötvös experiment. It is shown that ${\gamma }_Y$ is best detected as an unobserved neutral in the decays $K^{\pm }\to {\pi }^{\pm }{\gamma }_Y$ and $K_S^0\to {\pi }^0{\gamma }_Y$, and that existing experimental limits provide nontrivial constraints on the strength and range of possible hypercharge couplings.

This paper presents measurements of the inclusive production cross sections of $\Lambda$ baryons in $e^{+}{e}^{-}$ annihilations at $\sqrt{s}=29\mathrm{}$ GeV. The data sample corresponds to an integrated luminosity of 256 ${\mathrm{pb}}^{-1\mathrm{}}$ collected with the High-Resolution Spectrometer at the SLAC storage ring PEP. Comparisons are made to the predictions of the Lund model. The data are well described with use of a strange-diquark suppression parameter, $\frac{\left(\frac{\mathrm{us}}{\mathrm{ud}}\right)}{\left(\frac{s}{d}\right)}$, of 0.89 ± ${0.10}_{-0.16\mathrm{}}^{+0.56\mathrm{}}$, and the measured ${\Lambda }_c\to \Lambda +X$ branching ratio of (23 ± 10)%.

A systematic study of meson multiplicity as a function of energy at energies up to 100 GeV/u in nucleus-nucleus collisions has been made, using cosmic-ray data in nuclear emulsion. The data are consistent with simple nucleon-nucleon superposition models. Multiplicity per interacting nucleon in $\mathrm{AA}$ collisions does not appear to differ significantly from $\mathrm{pp}$ collisions.

The emission of complex particles at intermediate energies has been characterized through the reverse-kinematics reactions 25- and 30-MeV/u ${}_{}{}^{93}{}_{}{}^{}\mathrm{Nb}$ + ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$. Complex particles observed in binary decays from very hot incomplete-fusion intermediates are shown to originate from compound-nucleus decay, by means of kinetic energies, angular distributions, and absolute yields. The process of complex-particle emission provides a method, applicable throughout the Periodic Table, for studying compound nuclei with temperatures and excitation energies near the expected limit of their existence.

Large-order perturbation theory has been applied, for the first time, to the Stark effect for ${\mathrm{H}}_2^{+}$, yielding the Rayleigh-Schrödinger ground-state eigenvalue (polarizability) series through twentieth order; previous expansions were limited to fourth order. The calculations were performed nonadiabatically (i.e., without invoking the Born-Oppenheimer approximation) by means of the perturbational-variational Rayleigh-Ritz formalism. The leading terms of the Rayleigh-Schrödinger polarizability series so obtained provide the most accurate values thus far determined for ${\alpha }_{\mathrm{zz}}$ and ${\gamma }_{\mathrm{zzzz}}$.

Spin asymmetries are presented for superelastic scattering of spin-polarized electrons from spin-polarized $M_L=+1\mathrm{}$ and $M_L=-1\mathrm{}$ states of the $\mathrm{Na} {3P}_{\frac{3}{2}}$ atom. The incident-energy dependence at a scattering angle of 30° is shown for energies of 1.26 to 11.76 eV. In addition, angular dependences over the range 5° to 40° are given at 2.0 and 9.26 eV. Large differences are seen between the spin asymmetries for the two $M_L$ sublevels of the excited state, with the $M_L=-1\mathrm{}$ asymmetry reaching a value of 100% at 2 eV and 35° scattering angle, corresponding to pure singlet scattering.

An adiabatic treatment in hyperspherical coordinates is used to predict the existence of resonant structures in ${\mathrm{Ps}}^{-}$ (Ps denotes positronium) photodetachment. This highly correlated system displays a weak series of narrow Feshbach resonances lying just below the $\mathrm{Ps}\mathrm{}(n=2\mathrm{})\mathrm{}$ threshold, while a single strong shape resonance dominates the photodetachment spectrum above this threshold as in ${\mathrm{H}}^{-}$. Use of a "prediagonalized" representation of hyperspherical harmonics dramatically improves the convergence of the adiabatic calculation.

The question is raised as to whether the normalized spectrum of light remains unchanged on propagation through free space. It is shown that for sources of a certain class that includes the usual thermal sources, the normalized spectrum will, in general, depend on the location of the observation point unless the degree of spectral coherence of the light across the source obeys a certain scaling law. Possible implications of the analysis for astrophysics are mentioned.

Heat-transport measurements in a bulk normal-fluid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ mixture heated from below and over the range $-0.02\mathrm{}\lesssim \psi \lesssim 0.02$ of the separation ratio $\psi$ reveal a forward bifurcation with an initial slope $S\cong 0$ of the Nusselt number for large $\psi$, and a backward bifurcation for $\psi <{\psi }_b\cong 0.006$. At ${\psi }_b$, $S\cong 1$. The critical line $\Delta T_c\left(\psi \right)$ has two branches which meet at $\psi \cong -0.003\mathrm{}$, and which we attribute to the expected stationary and Hopf bifurcation lines. However, stable oscillations bifurcating from the conduction state exist only for $\psi \lesssim -0.015\mathrm{}$.

Multiple-quantum nuclear-magnetic-resonance techniques are used to study the distribution of hydrogen in hydrogenated amorphous silicon. Using the fact that multiple-quantum excitation is limited by the size of the dipolar-coupled spin system, we show that the predominant bonding environment for hydrogen is a cluster of four to seven atoms. For device-quality films, the concentration of these cluster defects increases with increasing hydrogen content. At very high hydrogen content, the clusters are replaced with a continuous network of silicon-hydrogen bonds.

The concept of collective pinning, which has proven successful in the theories of flux-line and charge-density-wave pinning, is outlined and its applicability to problems of various dimensionality is discussed. This concept is applied to the one-dimensional problem of dislocations weakly pinned by solute atoms. Within a self-consistent approach the critical shear stress for the onset of solution hardening is obtained. The qualitative agreement of the result with those of other approaches is explained by scaling laws.

We report measurements of the coherent elastic diffuse scattering of thermal neutrons from the local lattice distortions around deuterium in niobium. We show unambiguously that the heretofore accepted Kanzaki force model does not describe the experimental findings. Model calculations which include relaxation-time effects of the distortion field due to rapid motion of the defect give a satisfactory agreement with the measured intensity distribution. This model provides an explanation of the absence of a Snoek relaxation and relates the defect location, the defect-induced lattice distortion, and the defect diffusion in a self-consistent way.

We have measured the velocity and attenuation of longitudinal sound at 10 MHz in solid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ as a function of temperature from the melting temperature to as low as 12 mK. The measurements were made at molar volumes between 23.2 and 24.6 ${\mathrm{cm}}^3$ and at two different concentrations of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ impurities. In the sample containing less than 5 ppm of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ the velocity varies as $\frac{1}{T}$ at low temperatures and the attenuation varies exponentially with temperature. The sample containing 158 ppm ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ reveals very different behavior.

A defect consisting of an extra electron trapped at a four-coordinated silicon atom and stabilized by an adjacent interstitial lithium ion has been observed in quartz. It is formed by a double irradiation, first between 150 and 300 K to release the lithium ion from its associated ${\mathrm{Al}}^{3+}$ and then at 77 K to trap an electron at the free lithium ion. The $c$-axis ESR spectrum shows a splitting of 0.9 G from a ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ and 404.7 G from a ${}_{}{}^{29}{}_{}{}^{}\mathrm{Si}$ (thus, the defect does not resemble a lithium atom). Pairs of these defects may be responsible for the lack of electronic paramagnetism in quartz after room-temperature irradiation.

A theory for columnar microstructure is presented. Column orientation is predicted, and the tangent rule is shown to be an approximate special case of a more general relationship. Results also predict that columns occur only at low substrate temperature. All of these results agree with experimental data. In addition, a relationship is found between column width and mean square diffusion length. The theory substantiates the empirical suggestion that adatom mobility is an important parameter governing column development.