Using Monte Carlo methods with Wilson's lattice cutoff, the asymptotic-freedom scales of SU(2) and SU(3) gauge theories without quarks are calculated.

A search was made for five-quark "pseudobaryon" and four-quark baryonium states with a 1000-event sample of the reaction $\mathrm{pp}\to \mathrm{pp}\overline{p}p$ at 11.75 GeV/c. For states with widths ≲ 10 MeV/${\mathit{c}}^2$ and masses $M_{\overline{p}p}<2.2\mathrm{}$ GeV/${\mathit{c}}^2$ and $M_{\mathrm{pp}\overline{p}}<3.4\mathrm{}$ GeV/${\mathit{c}}^2$, upper limits on the product of the cross section and the branching ratio for forward-hemisphere production are measured to be ∼ 15 nb.

It is shown that the identification of gluon and quark jets in the process $e^{+}{e}^{-}$→ three jets is feasible if the gluon is radiated off heavy quarks. Gluon energy spectra are computed for $e^{+}{e}^{-}\to b\overline{b}g$ in the 30-40-GeV energy region and for $e^{+}{e}^{-}\to Z^0\to t\overline{t}g$.

A model for pion diffractive dissociation as a two-stage process is examined, where first the pion breaks up to $q\overline{q}$ system, followed by the hadronization of this quark-antiquark system. This model appears to be consistent with the present experimental data. Implications of this hypothesis for a study of quark-antiquark jets is suggested.

The space-time development of jet hadronization is investigated in two-dimensional quantum electrodynamics. It is found that the characteristic space-time scale of jet hadronization is considerably shorter than the one given by approximately free propagation of quarks.

In the reaction $e^{+}{e}^{-}\to {\psi }^{\prime \prime }\mathrm{}\left(3770\right)\mathrm{}$, events containing either one to two electrons have been observed originating in semileptonic decays of $D$ mesons. A comparison of these samples provides a determination of the branching ratios: $b(D^0\to \mathrm{Xe}\nu )<\mathrm{}4.0\%$ (at 95% confidence level) and $b(D^{+}\to \mathrm{Xe}\nu )=\left({22.0}_{-2.2\mathrm{}}^{+4.4\mathrm{}}\right)\%$. These values imply that the ratio of $D^0$ and $D^{+}$ lifetimes is $\frac{\tau \left(D^{+}\right)}{\tau \left(D^0\right)}>4.3\mathrm{}$ (at 95% confidence level).

The fission barrier of ${}_{}{}^{153}{}_{}{}^{}\mathrm{Tb}$ was found to be 28.5±1.7 MeV, which is about 83% of the predicted liquid-drop value. This result is consistent with calculations of nuclear masses and with barriers obtained from ${}_{}{}^4{}_{}{}^{}\mathrm{He}$-induced fission. Barrier estimates of (51-65)% of liquid-drop values deduced for nonrotating nuclei from results of others appear to be in error.

Spectra of 172-MeV $\alpha$ scattering from ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ indicate in addition to giant monopole and quadrupole excitation new giant resonance structures in hadron scattering at $E_x=17.5\mathrm{}\pm 0.8 \mathrm{and} 21.3\pm 0.8$ MeV with corresponding widths of 4.8±0.8 and 5.9±0.8 MeV. The angular distributions indicate $L=3\mathrm{} \mathrm{and} 1$ giving rise to an interpretation as isoscalar giant octupole resonance (17.5 MeV, 60% energy-weighted sum-rule strength), and isoscalar giant dipole resonance (21.3 MeV, 90% energy-weighted sum-rule strength).

Bunching the density of a relativistic electron beam via the $\nabla B$ drift is analyzed for a beam propagating in a $\frac{1}{r}$ azimuthal magnetic field produced by a current driven in a wire. Substantial enhancement of the beam current is predicted.

$\nabla B$ transport, bunching, and focusing of relativistic electron beams give power deposition levels which may provide the absorbed fluxes of 100 TW/${\mathrm{cm}}^2$ believed necessary to drive breakeven inertial-confinement-fusion targets. Predicted depositions in excess of 100 (TW/g)/MA are presented here. These levels are up to two orders of magnitude higher than those previously calculated and appear to meet the absorbed-flux requirement.

A variational principle is proposed for constructing equilibria with low free energy in toroidal plasmas in which relaxation is dominated by a tearing mode of single helicity. States with current density vanishing on the boundary are constructed. Theoretical predictions are compared with experimental data from reversed field pinches and tokamaks.

Plasma-produced electrons have been trapped for long periods of time in orbits around a positively charged wire. Since the frequency of rotation of each electron increases if it loses kinetic energy and sinks into the positive-potential well, phase bunching resulting in intense microwave emission can be easily excited.

Anomalous, low-frequency Raman scattering from localized acoustic vibrations of roughness features on a metal surface are observed. The observed mode frequency shifts with excitation frequency and with the index of refraction of the surrounding medium. The shifts arise from resonant laser excitation of localized dipolar plasmons. This resonant optical coupling is a key to the phenomenon of enhanced Raman scattering from molecules adsorbed on rough metal surfaces.

NMR spin-lattice relaxation rates ${T_1}^{-1\mathrm{}}$ of ${}_{}{}^1{}_{}{}^{}\mathrm{H}$ in $a$-Si:H films exhibit a maximum near 40 K. Both the magnitude, the temperature, and frequency dependences of $T_1$ are well described by a model which assumes a coupling to disorder modes which are associated with some hydrogen atoms. Results suggest that some hydrogen sites may contribute to the electronic states within the gap.

The first direct measurements of the dissipation due to flow are performed and the effects of that flow on the NMR properties of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-$A$ are studied. A temperature-independent critical velocity $v_c=0.52\mathrm{}$ mm/s is observed, above which a pressure difference proportional to $v_s-v_c$ develops across our flow orifice. Simultaneously, the NMR frequency in ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-$A$ is lowered by an amount also proportional to $v_s-v_c$, in contrast to current theoretical predictions.

Novel computer simulations are described of the time evolution of an ordering model binary alloy following quenching from a disordered state at a high temperature. The results are interpreted with use of ideas of Lifshitz and of Cahn and Allen; the ordering process is described by a kinetic equation for the motion of the walls separating domains with different orderings. The characteristic length increases as $t^{\frac{1}{2}}$, and the structure function scales as $k{t}^{\frac{1}{2}}$.

Results are presented of a Monte Carlo study of the spinodal decomposition of a two-dimensional metamagnet, quenched from an initial high-temperature disordered state to below its tricritical point. It is found that the structure factors for both the order parameter and magnetization exhibit instability as manifested via growing peaks. The order-parameter structure factor $S(k,t)\mathrm{}$ is shown to exhibit an early-time scaling of the form $t^{-2x}S(k,t)=F\left(k{t}^x\right)$, with $x\simeq 0.35$, where $k$ is the wave number and $t$ the time.

A two-oscillator model, taking into account both the $Z_3$ and the $Z_{12}$ exciton, is used to calculate the polariton dispersion curve in CuCl. The new curve has three branches. Values of the parameters characterizing the two oscillators are given, which yield a good agreement between theoretical predictions calculated from this model and several experimental results.

Data are presented that suggest the existence of a long-range topological order in thin superconducting films below a characteristic temperature.

The Kondo Hamiltonian is exactly diagonalized with use of a modified Bethe Ansatz. The zero-temperature magnetic susceptibility is also calculated.