If the known fermions transform under $\mathrm{SU}{\mathrm{}\left(2\right)\mathrm{}}_L \otimes \mathrm{SU}{\mathrm{}\left(2\right)\mathrm{}}_R \otimes \mathrm{U}{\mathrm{}\left(1\right)\mathrm{}}_{B-L}$, then the two neutral vector gauge bosons must satisfy the bounds $83 \mathrm{GeV}<M_{Z_1}<116\mathrm{} \mathrm{GeV}$ and $M_{Z_2}>200\mathrm{}$ GeV. In addition, if mixing is negligible for the two charged vector gauge bosons, then $75 \mathrm{GeV}<M_{W_1}<97\mathrm{} \mathrm{GeV}$. These results come directly from analyzing existing experimental data and do not depend on any further theoretical assumptions, such as the value of $\frac{g_L}{g_R}$ or the choice of Higgs-boson representations.

Strong transitions to high-lying proton states are observed for the first time in the study of the ($\alpha , t$) and (${}_{}{}^3{}_{}{}^{}\mathrm{He}$, $d$) reactions on ${}_{}{}^{144}{}_{}{}^{}\mathrm{Sm}$ at 80- and 240-MeV incident energy, respectively. The excitation energies, angular distributions, and strengths of these states suggest that they arise from proton stripping to high-spin outer subshells, e.g., $1h_{\frac{9}{2}}$ and $1i_{\frac{13}{2}}$.

The observation of subthreshold production of $K^{-}$ in the reaction ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$+${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ at 2.1 GeV/ nucleon is reported. For production at 0° and 1 GeV/c, a $K^{-}$ cross section ($\frac{d^2\sigma }{\mathrm{dp}d\Omega }$) of 1.6 mb ${\mathrm{sr}}^{-1\mathrm{}}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{-1\mathrm{}}$ and an upper limit for $\overline{p}$ production of 3 nb ${\mathrm{sr}}^{-1\mathrm{}}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{-1\mathrm{}}$ were measured. Calculations incorporating the effect of nuclear Fermi momentum underpredict the $K^{-}$ yield by more than a factor of 20. Production mechanisms involving collective effects and equilibration are discussed.

A laser optical-pumping, double-resonance experiment was performed on electrodynamically confined ${}_{}{}^{171}{}_{}{}^{}\mathrm{Yb}_{}^{+}{}_{}{}^{}$ ions. The ground-state hyperfine splitting has been determined to be $\Delta W_{\mathrm{h}\mathrm{f}\mathrm{s}}=12\mathrm{}642812124.2\pm 1.4$ Hz. The ultimate linewidth obtained in this experiment was 60 mHz, corresponding to a line $Q$ of 0.2×${10}^{12}$. It was limited by the stability of the available frequency reference.

The linear hydrodynamics of a stationary suspension of randomly distributed, nondilute spheres in an incompressible fluid is rigorously studied with the aid of a scaling expansion method. A space-time coarse graining is carried out in a manner consistent with an expansion in sphere concentration $c$ to obtain a linear macroscopic transport equation, which is local in time but nonlocal in space, to order $c^2$. Fluctuations around the macroscopic motion are also investigated and are shown to be small for dimension $d>\mathrm{}2\mathrm{}$.

Optical bistability transients have been computed including one transverse Cartesian coordinate. With a Gaussian transverse input profile but weak diffractive coupling, the switchup intensity is radially dependent, and the output requires hundreds of round trips to reach steady state. Strong diffractive coupling results in whole-beam switchup and much faster convergence to steady state.

Parametric decay instability cascades with one wave heavily damped are examples of Lotka-Volterra time-dependent equation systems. These are shown to be constant Hamiltonian in nature and the cascades (at least) can display Hamiltonian chaos, even without ensemble averaging. It seems likely that sufficiently complicated systems of this type will usually be chaotic unless very near equilbrium. These conclusions apply as well to some chemical and population biology systems which obey similar equations.

Electrons heated by absorption of laser energy are shown to generate intense magnetic fields which rapidly spread from the edge of the laser spot along the target surface. The fields convectively transport hot electrons and confine a major fraction of the deposited laser energy in the corona. Eventually, this energy is lost to fast-ion blowoff or deposited at large distances from the spot. This model qualitatively explains many experimental observations of thermal-transport inhibition and fast-ion loss.

The critical behavior of two nonionic-amphiphile solutions showing a lower consolution point is investigated by laser-light scattering. The critical exponents $\gamma$ and $\nu$ take the values $\gamma =1.15\mathrm{}$ and $\nu =0.57\mathrm{}$ for the system ${\mathrm{H}}_2$O-${\mathrm{C}}_8$${\mathrm{Et}}_4$, and $\gamma =0.90\mathrm{}$ and $\nu =0.44\mathrm{}$ for ${\mathrm{H}}_2$O-${\mathrm{C}}_{12}$${\mathrm{Et}}_8$. Both sets of values are different from those previously found with the system ${\mathrm{H}}_2$O-${\mathrm{C}}_{12}$${\mathrm{Et}}_6$. The description of the observed nonuniversality of critical micellar solutions may require three-dimensional models which exhibit continuously varying critical exponents.

An extremely simple calculational method based on the effective medium theory is developed to describe chemisorption systems. It is tested for hydrogen chemisorbed on Ni(100) and (111). Good agreement with experiment is obtained for all quantities calculated: chemisorption energy, equilibrium position, vibrational frequency, and the energy of the hydrogen-induced level. The results indicate that hydrogen may exist under the first Ni layer of Ni(111), but that the binding here is weaker than outside the surface.

A model is proposed for coupled bond-orientational and herring-bone packing degrees of freedom in layered liquid crystals. Three distinct phases are possible: isotropic, and bond-orientationally ordered stacked hexatic with and without herring-bone order. The transition between the two ordered phases is first order. The isotropic-hexatic transition can be driven first order by fluctuations and becomes second order at a tricritical point. Available experimental data are consistent with our model.

The average field enhancement factors in each phase of two-component composites are shown to be simple functions of measurable quantities. From these results, rigorous upper bounds on enhancement factors are calculated and the microstructures for which they occur are identified. The estimation of field inhomogeneities from incomplete data is also discussed.

Experimental spectra of spin-polarized photoemission from well-defined ${\mathrm{Ni}}_{1-x}{\mathrm{Fe}}_x$ (100) surfaces for $x=0.2\mathrm{} \mathrm{and} 0.6$ are presented. They reflect the difference between occupied up- and down-spin densities of states of the bulk near the Fermi energy. It is shown that the majority bands are not full for $x=0.6\mathrm{}$, in contrast to $x=0.2\mathrm{}$ and pure Ni, and that the majority density of states dominates at the Fermi energy for $x=0.6\mathrm{}$. Current theories of ferromagnetic alloys do not fully account for the observed spin polarization.

If gravitinos of mass 1 keV (or similar particles) dominate the mass of the universe, a critical scale of galactic size arises due to their collisionless phase mixing. It is shown that density perturbation spectrum of gravitinos is relatively flat between galactic and cluster scales, unlike the massive neutrino case. If gravitinos form the dark matter, initial adiabatic fluctuations lead to a hierarchical picture of clustering. Galaxies form first, but dissipation is necessary for their survival.

The occurrence of sudden qualitative changes of chaotic (or "turbulent") dynamics is discussed and illustrated within the context of the one-dimensional quadratic map. For this case, the chaotic region can suddenly widen or disappear, and the cause and properties of these phenomena are investigated.

The projection method is a constructive proof of complete integrability of classical many-body systems. This method is extended to the quantum case. The wave functions and propagators of the $n$-particle Calogero systems are given in the form of integrals involving the wave functions and propagators of free motion in space of $n^2$ dimensions. Quantization of angular momentum in the large space yields solutions for discrete values of the coupling constant.

Direct electrons are observed in baryon events produced in $e^{+}{e}^{-}$ annihilation at center-of-mass energies above the ${\Lambda }_c{\overline{\Lambda }}_c$ threshold. These events are attributed to charmed-baryon pair production and subsequent ${\Lambda }_c$ semileptonic decay. Various semileptonic branching ratios of the ${\Lambda }_c$ are determined, including $B({\Lambda }_c\to e^{+}X)=(4.5\mathrm{}\pm 1.7)\%$.

Charge $\pm \frac{1}{3}$ heavy leptons can annihilate in heavy stars down to an abundance of ${10}^{-19\mathrm{}}$, without generating an isotropic $\gamma$-ray background. Observation of such leptons with this abundance, and the observed flux of cosmic neutrinos imply that (1) there is no primordial hydrogen on earth, (a) the first stars were heavy ($M\gtrsim 15M_{\odot }$), and (3) their formation took place at a red shift $1+z\gtrsim 20$.

A bound on the coupling strengths of a very light pseudoscalar particle is derived from stellar energy loss at various stages of evolution: the sun, red giants, and cooling white dwarfs. The dimensionless Yukawa and $2\gamma$ couplings must be less than ${10}^{-11\mathrm{}}$.

Eleven neutral and nine charged decays of charmed particles have been observed in a sample of 205 000 hadronic interactions in a 1.2-million-picture exposure of the SLAC Hybrid Facility bubble chamber to a 20-GeV/c backward-scattered laser beam. The charged and neutral lifetimes were determined to be ${8.2}_{-2.5\mathrm{}}^{+4.5\mathrm{}}$×${10}^{-13\mathrm{}}$ and ${6.7}_{-2.0\mathrm{}}^{+3.5\mathrm{}}$×${10}^{-13\mathrm{}}$ sec, respectively, with a ratio of ${1.2}_{-0.5\mathrm{}}^{0.9}$.