1,317 research outputs found

    b quark fragmentation

    Get PDF

    MACRIB High efficiency - high purity hadron identification for DELPHI

    Get PDF
    Analysis of the data shows that hadron tags of the two standard DELPHI particle identification packages RIBMEAN and HADSIGN are weakly correlated. This led to the idea of constructing a neural network for both kaon and proton identification using as input the existing tags from RIBMEAN and HADSIGN, as well as preproccessed TPC and RICH detector measurements together with additional dE/dx information from the DELPHI vertex detector. It will be shown in this note that the net output is much more efficient at the same purity than the HADSIGN or RIBMEAN tags alone. We present an easy-to-use routine performing the necessary calculations

    A neural network z-vertex trigger for Belle II

    Full text link
    We present the concept of a track trigger for the Belle II experiment, based on a neural network approach, that is able to reconstruct the z (longitudinal) position of the event vertex within the latency of the first level trigger. The trigger will thus be able to suppress a large fraction of the dominating background from events outside of the interaction region. The trigger uses the drift time information of the hits from the Central Drift Chamber (CDC) of Belle II within narrow cones in polar and azimuthal angle as well as in transverse momentum (sectors), and estimates the z-vertex without explicit track reconstruction. The preprocessing for the track trigger is based on the track information provided by the standard CDC trigger. It takes input from the 2D (rφr - \varphi) track finder, adds information from the stereo wires of the CDC, and finds the appropriate sectors in the CDC for each track in a given event. Within each sector, the z-vertex of the associated track is estimated by a specialized neural network, with a continuous output corresponding to the scaled z-vertex. The input values for the neural network are calculated from the wire hits of the CDC.Comment: Proceedings of the 16th International workshop on Advanced Computing and Analysis Techniques in physics research (ACAT), Preprint, reviewed version (only minor corrections

    Cerebellar Degeneration as Presenting Symptom of Recurrent Endometrial Stromal Sarcoma with Sex-Cord Elements

    Get PDF
    We report a 66-year-old woman with slowly progressive ataxia due to cerebellar atrophy. Imaging studies revealed multiple lesions in both the lungs and dorsal subpleural space. A biopsy identified the lesions as metastases of a low-grade endometrial stromal sarcoma containing sex-cord elements. The histological appearance was identical to a uterine tumor the patient was treated for with hysterectomy 16 years before. The metastases were removed surgically, and after 3 months ataxia had regressed. We conclude that the presenting cerebellar degeneration in this patient resulted from the metastatic recurrence of the endometrial tumor

    Two Photon Couplings of Hybrid Mesons

    Get PDF
    A new formalism is developed for the two photon production of hybrid mesons via intermediate hadronic decays. In an adiabatic and non-relativistic context with spin 1 pair creation we obtain the first absolute estimates of unmixed hybrid production strengths to be small (0.03 - 3 eV) in relation to experimental meson widths (0.1 - 5 keV). Within this context, two photon experiments at Babar, Cleo II, LEP2 and LHC therefore strongly discriminate between hybrid and conventional meson wave function components, filtering out conventional meson components. Decay widths of unmixed hybrids vanish. Conventional meson two photon widths are roughly in agreement with experiment.Comment: 15 pages, LaTeX, 2 postscript figures, uses epsf. Rewritten for clarificatio

    Localized Drug Delivery Systems in High‐Grade Glioma Therapy—From Construction to Application

    Get PDF
    High-grade gliomas are the most common and most malign primary brain tumors. Current therapy approaches only reach unsatisfactory results, still not providing a long-lasting time to relapse or a curative treatment. A novel approach to overcome the present challenges of medical attendance, as drug resistance, systemic side effects, and limited drug availability due to the blood-brain barrier, are localized drug delivery systems (DDSs), which are already used in clinical trials. Further development of this therapy regime may clearly improve patient's outcomes. In order to design compact, biocompatible, robust, and highly flexible systems which permit a prolonged drug release, a broad knowledge of the technical and medical field is required. Thus, this interdisciplinary article reviews different designs, testing, and validation models, and finally, clinical applications of localized DDSs, to utilize this available experience as a basis for the desperately needed reform of glioma treatment
    corecore