688 research outputs found

    Interplay of Soft and Hard Interactions in Nuclear Shadowing at High Q2Q^2 and Low x

    Get PDF
    Nuclear shadowing corrections are dominated by soft interaction and grow as function of 1/x1/x more slowly than the single scattering term, which has an essential contribution from hard interaction. Therefore, we predict vanishing nuclear shadowing at very low xx provided that Q2Q^2 is high and fixed. At the same time, at medium and low Q2Q^2, nuclear shadowing grows with 1/x1/x as is well known for soft hadronic interactions.Comment: Latex file, 8 pages including 4 Postscript figures. To appear in the Proceedings of the Workshop on Future Physics at HERA, DESY, September 25, 1995 -- May 31, 199

    Possible influence of the two string events on the hadron formation in a nuclear environment

    Full text link
    One of the basic assumptions of the string model is that as a result of a DIS in nucleus a single string arises, which then breaks into hadrons. However the pomeron exchange considered in this work, leads to the production of two strings in the one event. The hadrons produced in these events have smaller formation lengths, than those with the same energy produced in the single string events. As a consequence, they undergo more substantial absorption in the nuclear matter

    Systematics of Leading Particle Production

    Get PDF
    Using a QCD inspired model developed by our group for particle production, the Interacting Gluon Model (IGM), we have made a systematic analysis of all available data on leading particle spectra. These data include diffractive collisions and photoproduction at HERA. With a small number of parameters (essentially only the non-perturbative gluon-gluon cross section and the fraction of diffractive events) good agreement with data is found. We show that the difference between pion and proton leading spectra is due to their different gluon distributions. We predict a universality in the diffractive leading particle spectra in the large momentum region, which turns out to be independent of the incident energy and of the projectile type.Comment: 13 pages, Latex, 4 ps figures. To appear in Phys. Rev.

    CPMS-improving patient care in Europe via virtual case discussions

    Get PDF
    Purpose The core task of European Reference Networks (ERNs) is to reduce health care inequalities throughout Europe for all patients with rare and complex conditions. A secure web-based application for virtual consultations, the Clinical Patient Management System (CPMS), was developed by the EU to provide expert specialized care for all these patients. This review analyses the opportunities and difficulties that the implementation of this virtual network implies for physicians as well as for the patients. Methods European Reference Network on Rare Endocrine Conditions (Endo-ERN) installed an Operational Helpdesk (OH) to support their members in using CPMS. The OH initiated several actions to facilitate and increase the usage of CPMS. Satisfaction with the system and reasons for low participation rates in virtual case discussions were analyzed by different surveys. Results The number of CPMS users increased constantly, but the active usage of the system remains insufficient. Main reasons were technical difficulties, lack of time and insufficient awareness about CPMS in experts and patients throughout Europe. Still, outcomes of the virtual discussions are considered useful by involved experts and the discussions have provided topics for educational webinars and research. Conclusions CPMS is a secure system with many advantages compared to previous ways of consulting experts but also difficulties that need to be overcome with future strategies. By facilitating its use and increasing awareness among all relevant European experts and patients, CPMS can help to make the existing expertise available for all patients with rare (endocrine) conditions throughout Europe as it was intended.Diabetes mellitus: pathophysiological changes and therap

    Astroparticle Physics with a Customized Low-Background Broad Energy Germanium Detector

    Full text link
    The MAJORANA Collaboration is building the MAJORANA DEMONSTRATOR, a 60 kg array of high purity germanium detectors housed in an ultra-low background shield at the Sanford Underground Laboratory in Lead, SD. The MAJORANA DEMONSTRATOR will search for neutrinoless double-beta decay of 76Ge while demonstrating the feasibility of a tonne-scale experiment. It may also carry out a dark matter search in the 1-10 GeV/c^2 mass range. We have found that customized Broad Energy Germanium (BEGe) detectors produced by Canberra have several desirable features for a neutrinoless double-beta decay experiment, including low electronic noise, excellent pulse shape analysis capabilities, and simple fabrication. We have deployed a customized BEGe, the MAJORANA Low-Background BEGe at Kimballton (MALBEK), in a low-background cryostat and shield at the Kimballton Underground Research Facility in Virginia. This paper will focus on the detector characteristics and measurements that can be performed with such a radiation detector in a low-background environment.Comment: Submitted to NIMA Proceedings, SORMA XII. 9 pages, 4 figure

    The phase diagram of NiSi under the conditions of small planetary interiors

    Get PDF
    The phase diagram of NiSi has been determined using in situ synchrotron X-ray powder diffraction multi-anvil experiments to 19 GPa, with further preliminary results in the laser-heated diamond cell reported to 60 GPa. The low-pressure MnP-structured phase transforms to two different high-pressure phases depending on the temperature: the Δ-FeSi structure is stable at temperatures above ∌1100 K and a previously reported distorted-CuTi structure (with Pmmn symmetry) is stable at lower temperature. The invariant point is located at 12.8 ± 0.2 GPa and 1100 ± 20 K. At higher pressures, Δ -FeSi-structured NiSi transforms to the CsCl structure with CsCl-NiSi as the liquidus phase above 30 GPa. The Clapeyron slope of this transition is -67 MPa/K. The phase boundary between the Δ -FeSi and Pmmn structured phases is nearly pressure independent implying there will be a second sub-solidus invariant point between CsCl, Δ -FeSi and Pmmn structures at higher pressure than attained in this study. In addition to these stable phases, the MnP structure was observed to spontaneously transform at room temperature to a new orthorhombic structure (also with Pnma symmetry) which had been detailed in previous ab initio simulations. This new phase of NiSi is shown here to be metastable

    Standalone vertex ïŹnding in the ATLAS muon spectrometer

    Get PDF
    A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

    Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

    Get PDF
    Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ Îł, H → Z Z∗ →4l and H →W W∗ →lÎœlÎœ. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined ïŹts probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

    Get PDF
    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio
    • 

    corecore