We study the behavior of the string tension in the SU(3) lattice pure-gauge theory close to the deconfining critical point. We find very large correlation lengths, increasing with the lattice size. This result is strongly suggestive of a second-order phase transition, and excludes the presence of a strong first-order transition.

A method of obtaining the nonperturbative solution to quantum chromodynamics is presented. By a diagrammatic calculation a condensation parameter can be evaluated for small coupling. This method is applied to the chiral-symmetry-breaking solution. The relation between the sign of the anomalous dimension and the condensation of the corresponding operator is also clarified.

This paper examines the validity of the ladder approximation in gauge theories such as technicolor theories in which the coupling is a slowly running function of momentum and is large enough to trigger spontaneous chiral-symmetry breaking. We find that the next-higher-order terms beyond the ladder approximation amount to only a 1%-20% correction, depending on the fermion representation. This indicates that the ladder expansion may provide a much better description of chiral-symmetry breaking than previously thought.

We have performed a partial-wave analysis of the $K^{+}{K}_S^0{\pi }^{-}$ system produced in the reaction ${\pi }^{-}p\to K^{+}{\overline{K}}^0{\pi }^{-}n$ at 8 GeV/c. We present the results of the analysis of 30740 events in the mass range 1.24-1.60 GeV/${\mathit{c}}^2$, with $0.0\le -t\le 1.0$ ${\mathrm{GeV}}^2$/${\mathit{c}}^2$. In the 1.28-GeV/${\mathit{c}}^2$ mass region, we see evidence for a $J^{\mathrm{PG}}=0^{-+}$ resonance in addition to the resonant $1^{++}$ wave. We observe a $0^{-+}$ resonance and possibly a small $1^{++}$ resonance in the 1.42-GeV/${\mathit{c}}^2$ region. We also observe a $1^{++}$ state near 1.5 GeV/${\mathit{c}}^2$.

We present new measurements of the analyzing power for $\mathrm{np}$ scattering at 10.03 MeV accurate to ± 1 × ${10}^{-3\mathrm{}}$. A new source of systematic error, related to resonances in $n-{}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ scattering in the neutron detectors, is discussed. The interaction of the neutron magnetic moment with the Coulomb field of the proton is found to make a significant contribution to the analyzing power at the present level of accuracy. The results are compared to predictions of nucleon-nucleon potential models. New, improved values are reported for the $p$ and $d$-wave spin-orbit phase-shift splittings.

The vector analyzing power for the $n+d\to n+n+p$ breakup reaction was measured at 12 MeV. Data for $n-p$ final-state interaction and $n-p$ quasifree scattering, along with elastic-scattering data, are compared to rigorous three-nucleon calculations using the Paris and Bonn $N-N$ potentials. Calculations agree with the quasifree data and with the elastic and $n-p$ final-state-interaction data except around ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}=120\mathrm{}°$.

An alternative formulation of the extended mean-field equations proposed in 1981 by Balian and Vénéroni is presented, together with a numerical method of solution. The time evolution and approach to equilibrium of a spherically symmetric compressed nucleus are then investigated.

The long-range van der Waals state of $\mathrm{D}_2^{}{}_{}{}^{+}$ has been characterized through observations of electronic transitions from the ground state.

The infrared-absorption spectrum of the previously unobserved NeHF molecule has been predicted from an ab initio quantum-mechanical calculation and subsequently determined for the first time by direct measurement. The two procedures yield remarkable agreement in the positions, widths, and intensities of the infrared spectral lines. The calculations predict, and the experiments confirm, highly unusual vibrational dynamics.

We have demonstrated a novel diffraction grating for atoms. A collimated beam of sodium atoms with a de Broglie wavelength of 17 pm was diffracted by transmission through an array of slits with a spatial period of 0.2 μm formed in a gold membrane. This is the first reported diffraction of atoms by a fabricated periodic structure. Our transmission grating for atoms can divide or recombine an atomic beam coherently, and may provide the easiest route to the realization of an atom wave interferometer.

The threshold behavior for triple photoionization of atomic oxygen and neon has been studied over a range of 10 eV in order to test the Wannier law for multiple ionization and its applicability to different states of angular momentum and spin. The cross sections are found to follow a power law in $E$ with an exponent of 2.17 ± 0.09, which is consistent with the value of 2.162 predicted by Klar and Schlecht. The energy range of validity of this law appears to be about 5.5 eV. For the case of atomic oxygen the absolute value for the constant of proportionality is found to be 5.3 × ${10}^{-24\mathrm{}}$ ${\mathrm{cm}}^2$/${\mathrm{eV}}^{2.17}$.

Heterodyne measurements of the field of Lorenz-type far-infrared-laser intensity pulsations reveal two different kinds of chaotic attractors. At high pressure, a symmetric attractor is found (two saddle foci), representing (heteroclinic) Lorenz-type chaos. At lower pressure, in accordance with theoretical modeling, an asymmetric attractor (one saddle focus) is found, generating (homoclinic) Roessler- or Shilnikov-type chaos. Detuned lasers exhibit phase switches smaller than $\pi$ as predicted.

We calculate from first principles the frequency-dependent permeability $\kappa \left(\omega \right)$ in porous media for a variety of microstructures. It is found that when $\kappa \left(\omega \right)$ is scaled by its static value ${\kappa }_0$ and the frequency by a characteristic ${\omega }_c$ particular to the sample, the resulting function exhibits excellent universal behavior independent of microstructure. We advance arguments that delineate the physical reason for the scaling behavior as well as the condition for its validity. Our predictions are supported by observed correlations in sedimentary rocks and experimental $\kappa \left(\omega \right)$ measurements.

We report experimental measurements of ac permeability made on a variety of fused glass beads and crushed glass in a frequency range of 0.1 Hz to 1 kHz. We observe a rollover in $\kappa \left(\omega \right)$ from a viscous flow regime to an inertial one, and determine the values of the transport coefficients in both the high-frequency limit and the low-frequency limit. A good agreement is found with the scaling theory $\frac{\kappa }{{\kappa }_0}=f\left(\frac{\omega }{{\omega }_c}\right)$ with only two independent parameters.

The 2D wave-envelope equations for the beat-wave-cascade system are studied analytically and numerically. An expression for the mean square width of the cascade envelope is obtained, and is used to predict the long-term behavior of the waves. The amplitude of a resonantly driven plasma wave falls significantly over a stage length because of enhanced diffraction of the cascade envelope. Conversely, detuning the pumps from the plasma frequency can lead to focusing of the envelope and a corresponding increase in plasmon amplitude of up to 200% over the same distance.

In DIII-D $H$-mode plasmas, large amplitude modulation of steep-edge electron-pressure gradients are observed during the occurrences of giant edge-localized modes (ELM's). For a considerable range of plasma currents (1 to 2 MA), the experimental pressure gradient before a giant ELM is close to the theoretically predicted marginal stability limit for the first regime of the ideal ballooning mode. These results, together with observations showing that ELM's originate in the region of bad curvature, strongly suggest that ELM's are triggered by ballooning mode instabilities.

The expansion of a two-electron-population plasma into vacuum is investigated in a controlled laboratory experiment. As the plasma expands, the colder electron population lags behind the energetic tail population, and a potential double layer, called a rarefaction shock, develops where the two separate. Upstream of this double layer, both electron populations exist; but downstream, only the tail electrons do. During the expansion, ions are accelerated to energies well above the tail electron energy.

The modulation instability caused by the coupling of a Langmuir wave to the ion motion is investigated in the domain of large $\frac{v_{\mathrm{L}}}{v_{\mathrm{te}}}>1\mathrm{}$ ratios, where $v_{\mathrm{L}}$ and $v_{\mathrm{te}}$ denote the pump Langmuir-wave quiver velocity and the electron thermal velocity, respectively. A convenient approximate expression for the growth rate is given for $\frac{v_{\mathrm{L}}}{v_{\mathrm{te}}}<50\mathrm{}{\left(\frac{A}{Z}\right)}^{\frac{1}{6}}$. The limitation of the beat plasmon growth due to the modulational instability is studied in the context of plasma beat-wave experiments and the maximum beat plasmon amplitude is determined numerically.

The formation of a potential is experimentally investigated in a high-speed collisionless plasma flow injected into a region of converging magnetic field lines. When the plasma passes through this region, a large increase in potential occurs there, resulting in electron acceleration along the magnetic field. A drastic end-plate effect on the generated potential is observed when the plasma comes in contact with the end plate.

We have made the first systematic observations of an increase in the viscosity of a dilute ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ solution at very low temperatures on the application of a large magnetic field by measuring the damping of second sound. The zero-field viscosities are used to evaluate the quasiparticle-quasiparticle interaction potential which enables an unambiguous prediction of the viscosity increase. The experimental results are in good agreement with this prediction.