Charm, Beauty and Top at HERA

Results on open charm and beauty production and on the search for top production in high-energy electron-proton collisions at HERA are reviewed. This includes a discussion of relevant theoretical aspects, a summary of the available measurements and measurement techniques, and their impact on improved understanding of QCD and its parameters, such as parton density functions and charm- and beauty-quark masses. The impact of these results on measurements at the LHC and elsewhere is also addressed.Comment: 103 pages, 60 figures, to be published in Prog. Part. Nucl. Phy

The MONOLITH project

MONOLITH is a proposed massive (34 kt) magnetized tracking calorimeter at the Gran Sasso laboratory in Italy, optimized for the detection of atmospheric muon neutrinos. The main goal is to establish (or reject) the neutrino oscillation hypothesis through an explicit observation of the full first oscillation swing. The Delta m^2 sensitivity range for this measurement comfortably covers the complete Super-Kamiokande allowed region. Other measurements include studies of matter effects and the NC/CC and anti-nu/nu ratio, the study of cosmic ray muons in the multi-TeV range, and auxiliary measurements from the CERN to Gran Sasso neutrino beam. Depending on approval, data taking with part of the detector could start in 2004. The detector and its performance are described, and its potential later use as a neutrino factory detector is addressed.Comment: 6 pages. Contribution to NUFACT'00 neutrino factory workshop, Monterey, CA, USA, May 22-26, 200

Pseudo-Dirac neutrinos as a potential complete solution to the neutrino oscillation puzzle

A solution for the neutrino mass and mixing pattern is proposed which is compatible with all available experimental data on neutrino oscillations. This solution involves Majorana neutrinos of the pseudo-Dirac type, i.e. $m_{\rm Majorana} \ll m_{\rm Dirac}$. The solar and atmospheric neutrino observations are mainly explained as $\nu_e - \nu_e^S$ and $\nu_\mu - \nu_\mu^S$ oscillations, w here S indicates the sterile (``righthanded'') partner of each neutrino generation, while the LSND result is interpreted in terms of standard $\nu_\mu - \nu_e$ oscillations. The resulting constrai nts on $\nu_\mu - \nu_\tau$ and $\nu_\tau - \nu_\tau^S$ oscillations are also discussed. This solution leaves room for a hierarchical mass and mixing scheme with a $\nu_\tau$ mass in the few eV r ange, as favoured by some dark matter scenarios. The apparent conflict with standard Big Bang nucleosynthesis is addressed and the implications for current and future experiments are discussed. I t is argued that both short and long baseline accelerator neutrino experiments are needed in order to decide between this solution and other oscillation scenarios

Summary of the NOW'98 Phenomenology Working Group

Summary of the Phenomenology Working Group at the Europhysics Neutrino Oscillation Workshop (NOW'98), 7-9 September 1998, Amsterdam.Comment: 66 page

Future Atmospheric Neutrino Detectors

Future experiments focusing on atmospheric neutrino detection are reviewed. One of the main goals of these experiments is the detection of an unambiguous oscillation pattern (nu_mu reappearance) to prove the oscillation hypothesis. Further goals include the discrimination of nu_mu - nu_tau and nu_mu - nu_sterile oscillations, and the detection of a potential small nu_mu - nu_e contribution. The search for matter effects in three or more flavour oscillations can be used to constrain hybrid oscillation models and potentially measure the sign of delta m^2. The detectors and measurement techniques proposed to achieve these goals are described, and their physics reach is discussed.Comment: 9 pages, invited talk at the XIX International Conference on Neutrino Physics and Astrophysics, Sudbury, Canada, June 16-21, 2000, to appear in Nucl. Phys. B (Proc. Suppl.

Speckle Reduction and Contrast Enhancement of Echocardiograms via Multiscale Nonlinear Processing

This paper presents an algorithm for speckle reduction and contrast enhancement of echocardiographic images. Within a framework of multiscale wavelet analysis, the authors apply wavelet shrinkage techniques to eliminate noise while preserving the sharpness of salient features. In addition, nonlinear processing of feature energy is carried out to enhance contrast within local structures and along object boundaries. The authors show that the algorithm is capable of not only reducing speckle, but also enhancing features of diagnostic importance, such as myocardial walls in two-dimensional echocardiograms obtained from the parasternal short-axis view. Shrinkage of wavelet coefficients via soft thresholding within finer levels of scale is carried out on coefficients of logarithmically transformed echocardiograms. Enhancement of echocardiographic features is accomplished via nonlinear stretching followed by hard thresholding of wavelet coefficients within selected (midrange) spatial-frequency levels of analysis. The authors formulate the denoising and enhancement problem, introduce a class of dyadic wavelets, and describe their implementation of a dyadic wavelet transform. Their approach for speckle reduction and contrast enhancement was shown to be less affected by pseudo-Gibbs phenomena. The authors show experimentally that this technique produced superior results both qualitatively and quantitatively when compared to results obtained from existing denoising methods alone. A study using a database of clinical echocardiographic images suggests that such denoising and enhancement may improve the overall consistency of expert observers to manually defined borders

Coupling of THz radiation with intervalence band transitions in microcavities

The strong coupling of THz radiation and material excitations can improve the quantum efficiency of THz emitters. In this paper, we investigate THz polaritons and antipolaritons based on valence band transitions, which allow TE coupling in a simple configuration. The approach can improve the quantum efficiency of THz based devices based on TE mode in the strong coupling regime of THz radiations and intervalence bands transitions in a GaAs/AlGaAs quantum wells. A Nonequilibrium Many Body Approach for the optical response beyond the Hartree-Fock approximation is used as input to the effective dielectric function formalism for the polariton/antipolariton problem. The energy dispersion relations in the THz range are obtained by adjusting the full numerical solutions to simple analytical expressions, which can be used for non specialists in a wide number of new structures and material systems. The combination of manybody and nonparabolicity at high densities leads to dramatic changes in the polariton spectra in a nonequilibrium configuration, which is only possible for intervalence band transitions