The interactions and correlations of charged rodlike colloidal particles are investigated using an ab initio approach which includes many-body inter-rod forces induced by nonlinear counterion screening. It is found that these forces can satisfactorily be described by an effective Yukawa segment model which in general differs from the traditional Derjaguin-Landau-Verwey-Overbeek theory. Whereas no simple analytical expression for the Yukawa parameters is available for the disordered phase, an exactly soluble cylindrical cell model reproduces the ab initio data quite well in the liquid-crystalline phase.

We show by extensive Green’s function calculations that the fingerprinting double peak observed in the title spectrum of the crystal is a pure nonatomic aggregation state effect, not to be seen in the gas phase spectrum. We clarify the mechanism for this effect as being due to the energy shift of hole-localized states induced by the crystal field and their strong mixing with close lying, otherwise Auger inactive, states. The generality of the phenomenon is discussed, identifying cases where it could be observed in the gas phase and not in the crystal.

We prove that for any Monte Carlo algorithm of Metropolis type, the autocorraletion time of a suitable ‘‘energy’’-like observable is bounded below by a multiple of the corresponding ‘‘specific heat.’’ This bound does not depend on whether the proposed moves are local or nonlocal; it depends only on the distance between the desired probability distribution π and the probability distribution ${\mathrm{\pi }}^{\mathrm{}\left(0\right)\mathrm{}}$ for which the proposal matrix satisfies detailed balance. We show, with several examples, that this result is particularly powerful when applied to nonlocal algorithms.

The supersymmetry properties of the asymptotically anti–de Sitter (adS) black holes of Einstein theory in 2+1 dimensions are investigated. It is shown that (i) the zero-mass black hole has two exact supersymmetries; (ii) extreme lM=‖J‖ black holes with M≠0 have only one; and (iii) generic black holes do not have any. It is also argued that the zero-mass hole is the ground state of (1,1) adS supergravity with periodic (‘‘Ramond’’) boundary conditions on the spinor fields.

We demonstrate that the Hagedorn-type growth of the number of observed meson states can be used to constrain the degrees of freedom of the underlying effective QCD string. We find that the temperature relevant for such string theories is not given by the usual Hagedorn value ${\mathit{T}}_{\mathit{H}}$≊160 MeV, but is considerably higher. This resolves an apparent conflict with the results from a static quark-potential analysis, and suggests that conformal invariance and modular invariance are indeed reflected in the hadronic spectrum. We also find that the ${\mathit{D}}_{\mathrm{\perp }}$=2 scalar string is in excellent agreement with data.

We explore the possibility that the existing data on like-sign dileptons at the Υ(4S) resonance consist of events arising from ${\mathit{B}}_{\mathit{d}}^{0\mathrm{-}}$B¯ ${}_{\mathit{d}}{}^0{}_{}{}^{}$ mixing and also from ΔB=-ΔQ transitions. We study the consequences of these nonstandard transitions for certain time asymmetries which are likely to be measured at the B factories.

We introduce a method for the study of CP-violating asymmetries in tagged states of neutral B mesons with arbitrary coherence properties. A set of time-dependent measurements is identified which completely specifies the density matrix of the initial state in a two-component space with basis vectors ${\mathit{B}}^0$ and B¯ ${}_{}{}^0{}_{}{}^{}$, and permits a determination of phases in the Cabibbo-Kobayashi-Maskawa matrix. For a given tagging configuration, the measurement of decays both to flavor eigenstates and to CP eigenstates provides the necessary information.

We demonstrate that an invisibly decaying Higgs boson with standard model coupling strength to tt¯ can be detected at the CERN Large Hadron Collider for masses ≲250 GeV.

Anomalous diffusion processes, dominated by rare events, are shown to exist and to play a central role in certain subrecoil laser cooling schemes. We present a new statistical analysis of these processes, in terms of Lévy flights, which provides a precise analytical description of the cooled atoms in the long time limit, where the standard methods of quantum optics are inappropriate. These analytical predictions are quantitatively checked by comparison with the results of quantum Monte Carlo simulations of the cooling process at intermediate times.

Two-step resonant laser-stimulated recombination of highly charged ions was performed for the first time. Nd:YAG laser pulses overlapped with an ${\mathrm{Ar}}^{18+}$ beam in the electron cooler of the ESR storage ring at GSI induced transitions from the continuum to the n=81 state of hydrogenlike ${\mathrm{Ar}}^{17+}$. To avoid reionization in the bending magnet before reaching the detector, the n=81 population was transferred to a state well below the reionization threshold by a Ti:sapphire laser. Tuning of this laser yielded the n=81 to 36 and 37 transition-line profiles. The two-step method provides access to detailed Rydberg spectroscopy in an electron beam environment.

We show that if a double-barrier mesoscopic p-i-n heterojunction is driven by an alternating voltage source, then Coulomb blockade and quantum confinement effects together can suppress the quantum fluctuations usually associated with electron and hole injection processes in semiconductors. It is therefore possible to generate heralded single-photon states without the need for a high-impedance current source. Since the frequency of the alternating voltage source determines the repetition rate of the single-photon states and the magnitude of the junction current, the present scheme promises high precision photon-flux and current standards.

Backaction evading (BAE) measurements are described for optical parametric amplification with polarization mixing. Quantum correlations between the ‘‘signal’’ and ‘‘meter’’ outputs from the BAE device lead to an observed photocurrent variance 30% (1.5 dB) below the signal shot-noise level and to an inferred variance 44% below the vacuum-state level for determination of the signal field given the meter reading. Together with its efficient information transfer, this BAE detector functions as a quantum optical tap and is suitable for implementing quantum nondemolition detection.

Experiments on double diffusive convection sustained by imposed vertical concentration gradients have been conducted in a novel thin isothermal parallelepiped cell. The measured critical Rayleigh number and the frequency of traveling waves are in reasonable accord with a stability analysis that predicts a tricritical condition all along the instability boundary. Visualization of the pattern from the side reveals that the asymptotic state immediately above the onset of instability consists of packets of traveling finite amplitude plumes.

The dynamic behavior of the L-H transition in the ASDEX-Upgrade tokamak is described. We focus on the periodic L-H-L transitions known as ‘‘dithering H mode’’ and show that there is an intrinsic time scale in this process which is characteristic for the L-H transition. We give a tentative explanation for the phenomenon using an extension of Itoh’s model for the L-H transition and find that this simple bifurcation model can qualitatively explain many of the experimental observations. According to our model, the dithering cycles are a limit cycle oscillation due to a difference in the response of the system to a rise in either T or n. The implications for H-mode theories are discussed.

The different patterns observed at a twist-grain-boundary– (${\mathrm{TGB}}_{\mathit{A}}$–) smectic-A (A) interface moving in a temperature gradient are quantified by measuring interface arclength scaling between two lengths characterizing these patterns. The ragged melting ${\mathrm{TGB}}_{\mathit{A}\mathrm{-}}$A interface results from the growth of ${\mathrm{TGB}}_{\mathit{A}}$ filaments into oriented A. We attribute the destruction of ${\mathrm{TGB}}_{\mathit{A}}$ when A grows into ${\mathrm{TGB}}_{\mathit{A}}$ to the second-order nature of the ${\mathrm{TGB}}_{\mathit{A}}$-cholesteric transition. These results are interpreted within a defect lattice model.

We simulate d=2 polymer growth by allowing for a branching probability b and an impurity concentration c (0≤b,c≤1). In the (b,c) space we find a critical line (locus of vanishing order parameter and diverging correlation length) which separates infinite from finite growth regimes; in particular, a nonzero critical value for b exists even for c=0.

We study phonon transport in random 3D lattices when the mean free path l becomes comparable to the lattice spacing a. Through numerical simulation, it is shown that in contrast to the electronic case, here the Ioffe-Regel criterion is inaccurate in the prediction of phonon localization. By using the Thouless criterion to pinpoint the mobility edge ${\mathrm{\omega }}_{\mathit{c}}$, a broad frequency regime is found below ${\mathrm{\omega }}_{\mathit{c}}$ where kl≤1 but the phonon transport is still diffusive. The diffusion constant in this regime is given quantitatively by ${\nu }_{\mathit{E}}$a/3, where ${\nu }_{\mathit{E}}$ is an energy transport velocity derived from a continuity relation.

Optical sum-frequency generation was used to study OH stretch vibrations of water molecules at fused quartz-water interfaces. The results indicate that orientations and bond ordering of interfacial water molecules are strongly affected by electrostatic interaction and hydrogen bonding of the molecules with the quartz surface.

X-ray reflectivity measurements have been carried out at the liquid/vapor interface of normal alkanes. The reflectivities over a large temperature range of different chain lengths (C20 and C36) provide a critical test of the various capillary wave models. Our data are most consistent with the hybrid model which allows for a molecular size dependent cutoff ${\mathit{q}}_{\max }$ for the capillary waves and an intrinsic interface width ${\mathrm{\sigma }}_0$.

The roughness and surface correlations of a surfactant monolayer at an oil-water interface in equilibrium with a small amount of middle-phase microemulsion were studied using x-ray scattering. High energy x rays in conjunction with tight instrumental resolution allow us to separate and quantify the specular reflectivity and surface diffuse scattering of the interface. The experimental results are explained using a height-height correlation function derived from a capillary wave model. The interface was found to have an intrinsic roughness of 85 Å and an interfacial tension of 0.11 dyn/cm.