Electron spin resonance analysis of the intrinsic density [${\mathit{P}}_{\mathit{b}}$] of interfacial ${\mathit{P}}_{\mathit{b}}$ (⋅Si≡${\mathrm{Si}}_3$) defects in thermal (111)Si/${\mathrm{SiO}}_2$ as a function of oxidation temperature ${\mathit{T}}_{\mathrm{ox}}$ in the range 200–1140°C reveals a close linear correlation with the average stress ${\mathrm{\sigma }}_{\mathrm{av}}$ in the superficial ${\mathrm{SiO}}_2$ layer. An almost constant high value [${\mathit{P}}_{\mathit{b}}$]∼1×${10}^{13}$ ${\mathrm{cm}}^{\mathrm{-}2}$ is found for ${\mathit{T}}_{\mathrm{ox}}$≤800 °C, while from this ${\mathit{T}}_{\mathrm{ox}}$ onward, [${\mathit{P}}_{\mathit{b}}$] decreases monotonically to <${10}^{10}$ ${\mathrm{cm}}^{\mathrm{-}2}$ along with ${\mathrm{\sigma }}_{\mathrm{av}}$→0 for ${\mathit{T}}_{\mathrm{ox}}$→1150 °C. The underlying effect is cooperative structural relaxation of the ${\mathrm{SiO}}_2$ layer initiating at ∼800 °C, thus gradually eliminating the need for ${\mathit{P}}_{\mathit{b}}$ formation to account for lattice mismatch.

We present dynamic light scattering data which show that aqueous gelatin gels display a power-law relaxation to a nonergodic background. In the pregel sol this power law is termined by a stretched exponential which restores ergodicity and which has a q dependent characteristic time proportional to the viscosity. The power-law exponent is q dependent and related to a characteristic length in the gel. Except for the q dependences these behaviors are similar to the α and β relaxation behavior in glasses. It is proposed that the different q dependences of the gels and glasses is a result of different characteristic length scales.

We show that, for physically reasonable bulk and surface properties, the lowest energy state of dense matter consists of quark matter coexisting with nuclear matter in the presence of an essentially uniform background of electrons. We estimate the size and nature of spatial structure in this phase, and show that at the lowest densities the quark matter forms droplets embedded in nuclear matter, whereas at higher densities it can exhibit a variety of different topologies. A finite fraction of the interior of neutron stars could consist of matter in this new phase, which would provide new mechanisms for glitches and cooling.

We consider Chern-Simons gauge theory on a torus with both nonrelativistic and relativistic matter. It is shown that the Hamiltonian and two total momenta commute among themselves only in the physical Hilbert space. We also discuss relations among degenerate physical states, degenerate vacua, and the existence of multicomponent Schrödinger wave functions.

We show that the charged Higgs sector in Weinberg’s model for CP violation can cause a large CP violation effect in t→bτ${\nu }_{\mathrm{\tau }}$. The asymmetry in the partial rate is dominated by contributions such as Z(and γ)-${\mathit{H}}^{+}$ box diagrams interfering with a (near-resonance) W tree diagram. But far more significant are the asymmetries in the partially integrated rates and in the energy between the ${\mathrm{\tau }}^{+}$ and the ${\mathrm{\tau }}^{\mathrm{-}}$. These stem from (near-resonance) W-tree–${\mathit{H}}^{+}$-tree interference.

The observation that the $b\to s\gamma$ decay rate is close to the standard model value implies a large mass for the charged Higgs boson in the minimum supersymmetric standard model (MSSM), which nearly closes the $t\to b{H}^{+}$ decay channel. For $m_t=150\mathrm{}$ GeV, the parameter region $m_A\lesssim 130$ GeV is excluded; this largely preempts searches at the CERN $e^{+}{e}^{-}$ collider LEP II and also partially excludes a region that would be inaccessible to MSSM Higgs boson searches at LEP II and at the Superconducting Super Collider and the CERN Large Hadron Collider.

Gluon fusion is the main production mechanism for Higgs bosons with masses up to several hundred GeV in pp collisions at the CERN Large Hadron Collider and Superconducting Super Collider. We present the QCD corrections to the fusion cross section for arbitrary Higgs boson and top quark mass values: gg→H(g), gq→Hq, and qq¯→Hg. The QCD correc tions are positive and they increase the cross section σ(pp→H) by about a factor of 1.5 to 1.7. The analysis applies to the production of Higgs particles in the standard model and also to the production of the CP-even Higgs particles in extensions of the Higgs sector as required, for example, by supersymmetric theories.

Inclusive jet cross sections have been measured in p¯p collisions at √s =546 and 1800 GeV, using the Collider Detector at Fermilab. The ratio of jet cross sections is compared to predictions from simple scaling and O(${\mathit{a}}_{\mathit{s}}^3$) QCD. Our data exclude scaling and lie (1.5–2.4)σ below a range of QCD predictions.

Measurements of the mass and lifetime of the ${\mathrm{\Xi }}_{\mathit{c}}^{+}$ decaying into ${\mathrm{\Xi }}^{\mathrm{-}}$${\mathrm{\pi }}^{+}$${\mathrm{\pi }}^{+}$ are presented. The data were accumulated by the Fermilab high-energy photoproduction experiment E687. The mass of the ${\mathrm{\Xi }}_{\mathit{c}}^{+}$ is measured to be 2464.4±2.0±1.4 MeV/${\mathit{c}}^2$ and the lifetime is measured to be 0.${41}_{\mathrm{-}0.08}^{+0.11\mathrm{}}$±0.02 ps.

A new framework, the variational shell model, is proposed to describe the structure of neutron-rich unstable nuclei. An application to ${}_{}{}^{11}{}_{}{}^{}\mathrm{Be}$ is presented. Contrary to the failure of the spherical Hartree-Fock model, the anomalous 1/$2^{+}$ ground state and its neutron halo are reproduced with the Skyrme (SIII) interaction. This state is bound due to dynamical coupling between the core and the loosely bound neutron, which oscillates between the 2${\mathit{s}}_{1/2}$ and the 1${\mathit{d}}_{5/2}$ orbits.

By a realistic dynamical microscopic reaction approach to ${}_{}{}^5{}_{}{}^{}\mathrm{He}$ we reproduce the empirical positions of the two S matrix poles associated with the 3/$2^{+}$ resonance, and unambiguously prove that it arises from the t+d channel. The picture is not coherent though, unless the presently adopted α+n phase shift, extracted partly from α+p scattering data, is assumed to be incorrect. It is pointed out that the analog resonance in ${}_{}{}^5{}_{}{}^{}\mathrm{Li}$ behaves very differently because the shadow pole is located on another Riemann sheet.

Experimental particle yield ratios from 14.6A-GeV/${\mathit{c}}^{28}$Si interactions with nuclei at intermediate impact parameters are correlated with the orientation of the transverse momentum of projectile fragments. The ${\mathrm{\pi }}^{\pm }$/p ratio increases and the (d+t)/p ratio decreases when fragments are deflected toward the observing spectrometer. Asymmetries are confined to the target rapidity region. Assuming a spectator participant model, these results suggest the presence of significant rescattering of particles with dependences on the collision geometry.

Using continuous-wave excitation to eliminate the problems inherent with pulsed laser measurements of nonlinear transitions, we have measured the $1^3$${\mathit{S}}_{1\mathrm{-}}$$2^3$${\mathit{S}}_1$ interval in positronium (Ps) to be 1 233 607 216.4±3.2 MHz. The quoted 2.6 ppb (parts per ${10}^9$) uncertainty is primarily due to the determination of the Ps resonance relative to the ${\mathrm{Te}}_2$ reference line, with a 1.5 ppb contribution from a recent calibration of the ${\mathrm{Te}}_2$ line relative to the hydrogen 1S-2S transition. The uncertainty corresponds to 3.5×${10}^{\mathrm{-}5}$ of the ${\mathrm{\alpha }}^2$${\mathit{R}}_{\mathrm{\infty }}$ QED contribution to the $1^3$${\mathit{S}}_{1\mathrm{-}}$$2^3$${\mathit{S}}_1$ interval. Our measurement is sufficiently accurate to provide a test of the as yet uncalculated ${\mathrm{\alpha }}^4$${\mathit{R}}_{\mathrm{\infty }}$ QED corrections.

We investigated the frequency-doubling properties of light beams whose transverse profile is given by the zero-order Bessel function ${\mathit{J}}_0$(r), Bessel beams. Phase-matched second-harmonic generation in a KDP crystal was observed at angles usually not suited for phase matching. It is thereby demonstrated that under certain circumstances, Bessel beams can be viewed as light beams with tunable wavelength. A variety of applications in the field of nonlinear optics is expected.

It has been a long-standing problem to understand the eigenfunctions of a system whose classical analog is strongly chaotic. We show that in some cases the eigenfunctions can be constructed by purely semiclassical calculations.

It is demonstrated that scattering by a rough surface can be described in terms of the coherent transfer function, which was first developed to describe the process of imaging. The two-dimensional (one transverse and one longitudinal) coherent transfer function for confocal imaging is presented for a high-angle theory. From this an effective transfer function for imaging of rough surfaces is developed, based on the Kirchhoff approximation. It is described how confocal imaging can be used to investigate various scattering mechanisms, and can be used for reconstruction of surface profiles in the Kirchhoff approximation.

The spontaneous Raman effect in ${\mathrm{C}}_6$${\mathrm{H}}_6$ is investigated in the QED-vacuum confinement condition in the Casimir topology of an optical microcavity as a prototype inelastic quantum-scattering process at optical frequencies. The confinement determines a dramatic enhancement (over a factor of ${10}^3$), inhibition, and directional effects on the scattering intensity. Apart from its relevance in atomic and molecular spectroscopy, the work establishes a new perspective in the field of QED scattering involving quantum particles with any energy.

We show how the generation of vacuum uv radiation can be doubly- enhanced by using strong external electromagnetic fields so that one can simultaneously make use of (a) the amplification of the fundamental as it propagates through the medium and (b) the near-zero absorption of the generated vacuum uv radiation. We include in the analysis the effects of propagation and pump depletion.

We include the effect of density-dependent near dipole-dipole interactions in order to generalize the theory of a simple three-level system that exhibits lasing without inversion and an enhanced index of refraction at zero absorption. For certain values of atomic density, our generalized theory predicts a novel enhancement of inversionless gain and absorptionless index by more than 2 orders of magnitude.

Phase and amplitude dynamics of a subcritical period-doubling bifurcation are experimentally characterized in the nonlinear strain response (at f≊10 kHz) of a magnetostrictive oscillator. Low frequency (${\mathit{f}}_{\mathrm{mod}}$≤0.1 Hz) modulation of the observed subcritical bifurcation provides a phase-reversing time series whose power spectrum tends to conceal frequency components. An event counting technique developed for characterizing the phase-slip dynamics of the time series reveals a substantial component at half the modulation frequency (f/2) as well as at f. The event counting technique is applied to observe stochastic resonance for the first time in a tristable system.