SUSY Searches in All-Hadronic States with Large MET at the LHC

The CMS and ATLAS search strategy for SUSY in inclusive multijet plus high missing transverse energy final states is reviewed. This canonical SUSY signature may be a viable discovery channel for low mass SUSY in the early phase of the LHC. Methods for Standard Model background estimates, MET studies and filters for instrumental background are presented.Comment: Submitted for the SUSY07 proceedings, 4 pages, LaTeX, 13 eps figure

Q(2) dependence of nuclear transparency for exclusive rho(0) production

Exclusive coherent and incoherent electroproduction of the rho(0) meson from H-1 and N-14 targets has been studied at the HERMES experiment as a function of coherence length (l(c)), corresponding to the lifetime of hadronic fluctuations of the virtual photon, and squared four-momentum of the virtual photon (-Q(2)). The ratio of N-14 to H-1 cross sections per nucleon, called nuclear transparency, was found to increase (decrease) with increasing l(c) for coherent (incoherent) rho(0) electroproduction. For fixed l(c), a rise of nuclear transparency with Q(2) is observed for both coherent and incoherent rho(0) production, which is in agreement with theoretical calculations of color transparency

Evidence for quark-hadron duality in the proton spin asymmetry A(1)

Spin-dependent lepton-nucleon scattering data have been used to investigate the validity of the concept of quark-hadron duality for the spin asymmetry A(1). Longitudinally polarized positrons were scattered off a longitudinally polarized hydrogen target for values of Q(2) between 1.2 and 12 GeV2 and values of W-2 between 1 and 4 GeV2. The average double-spin asymmetry in the nucleon resonance region is found to agree with that measured in deep-inelastic scattering at the same values of the Bjorken scaling variable x. This finding implies that the description of A(1) in terms of quark degrees of freedom is valid also in the nucleon resonance region for values of Q(2) above 1.6 GeV2

Lattice Formulation of the Standard Model

Combining the Kaplan surface mode approach for chiral fermions with added terms motivated by Eichten and Preskill suggests the possibility for a lattice regularization of the standard model which is finite, exactly gauge invariant, and only has physically desired states in its low energy spectrum. The conjectured scheme manifestly requires anomaly cancelation and explicitly contains baryon and lepton number violating terms.Comment: 11 pages, late

Portable Resistive Plate Chambers for Muography in confined environments

Muography (or muon radiography) is an imaging technique that relies on the use of cosmogenic muons as a free and safe radiation source. It can be applied in various fields such as archaeology, civil engineering, geology, nuclear reactor monitoring, nuclear waste characterization, underground surveys, etc. In such applications, sometimes deploying muon detectors is challenging due to logistics, e.g. in a narrow underground tunnel or mine. Therefore, we are developing muon detectors whose design goals include portability, robustness, autonomy, versatility, and safety. Our portable muon detectors (or ``muoscopes'') are based on Resistive Plate Chambers (RPC), planar detectors that use ionization in a thin gas gap to detect cosmic muons. Prototype RPCs of active area $16 \times 16~cm^2$ and $28 \times 28~cm^2$ were built in our laboratories at Louvain-la-Neuve (UCLouvain) and Ghent (UGent) to test and compare various design options. Benefiting from the experience gained in building and operating these prototypes, we are proceeding towards the development of improved prototypes with more advanced technical layout and readiness. In this paper we provide the status of our performance studies, including the cross-validation of the two types of prototypes in a joint data taking, and an outline of the direction ahead

Radial distribution of dilated intercellular spaces of the esophageal squamous epithelium in patients with reflux disease exhibiting discrete endoscopic lesions

Introduction: Dilatation of intercellular spaces of the esophageal squamous epithelium has been suggested as a marker of early acid reflux-induced damage. This change is a potentially useful addition to histomorphological changes that represent so called minimal endoscopic lesions. We have assessed dilatation of intercellular spaces with regard to: (1) interobserver variability, and (2) whether the incidence of this varies between 'red streaks' and the adjacent normal looking squamous epithelium. Methods: Esophageal biopsies from 44 patients with chronic gastro-esophageal reflux (GERD) were evaluated. At endoscopy, these patients had one or more red streaks on the tops of the mucosal folds in the distal esophagus. Biopsies were taken from the red streaks and from the normal-appearing mucosa 1 cm lateral to the red streaks. Biopsies were assessed in a blinded fashion by two independent pathologists (MV & RF). Criteria for assessing intercellular space dilatation were evaluated and agreed on prior to the study. Results: Good interobserver agreement was recorded (kappa = 0.82 at the streaks and 0.77 for the control tissues) for absence/presence of intercellular space dilatation. Red streak and control biopsies differed significantly (p = 0.0001), with respect to presence of dilated intercellular spaces, with 90.5 % of the former demonstrating this as present compared to 56.1% in the controls. Conclusion: This study supports the concept that esophageal mucosal minimal changes due to reflux is localised and that dilatation of intercellular spaces is an early sign of reflux-induced epithelial damage. The low interobserver variability in the assessment of intercellular space dilatation suggests that this may be a useful variable for assessment of early signs of acid-reflux induced damage to the squamous epithelium of the esophagus by use of light microscopy. Copyrigh

The first determination of Generalized Polarizabilities of the proton by a Virtual Compton Scattering experiment

Absolute differential cross sections for the reaction (e+p -> e+p+gamma) have been measured at a four-momentum transfer with virtuality Q^2=0.33 GeV^2 and polarization \epsilon = 0.62 in the range 33.6 to 111.5 MeV/c for the momentum of the outgoing photon in the photon-proton center of mass frame. The experiment has been performed with the high resolution spectrometers at the Mainz Microtron MAMI. From the photon angular distributions, two structure functions which are a linear combination of the generalized polarizabilities have been determined for the first time.Comment: 4 pages, 3 figure