Results 1 - 10 of 1923
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[en] We present a novel vertex finding technique. The task is formulated as a discrete-continuous optimisation problem in a way similar to the deformable templates approach for the track finding. Unlike the track finding problem, ''elastic hedgehogs'' rather than elastic arms are used as deformable templates. They are initialised by a set of procedures which provide zero level approximation for vertex positions and track parameters at the vertex point. The algorithm was evaluated using the simulated events for the LHC CMS detector and demonstrated good performance. (orig.)
[en] The fast vertex fitting method [P. Billoir and S. Qian, Nucl. Instr. and Meth. A 311 (1992) 139] has been enhanced by a steering procedure which performs the track selection to insure the vertex fitting quality. Meanwhile, a sign error in a formula in the above publication has been corrected. ((orig.))
[en] Positron Emission Particle Tracking was successfully used in a wide range of industrial applications. This technique primarily uses a single positron emitting tracer particle. However, using multiple particles would provide more comparative information about the physical processes taking place in a system such as mixing or fluidised beds. In this paper, a unique method that enables us to track more than one particle is presented. This method is based on the midpoint of the closest distance between two trajectories or coincidence vectors. The technique presented in this paper employs a clustering method
[en] Pixel detectors will be extremely useful in many future experiments. Firstly, due to their very small size, they have a very low intrinsic noise and are thus intrinsically radiation resistant. Secondly, their true 3-D capability improves the tracking efficiency and ghost rejection. They can then be close to the beam axis at the very high planned accelerator luminosities for improved vertexing. Several smart data-driven architectures are being considered for use at LHC and will be tested soon. (orig.)
[en] The AMS-02 tracker is surrounded by a highly efficient scintillator screen, the Anti-Coincidence Counter (ACC). It is used for suppressing tracks from outside the main tracker acceptance. We describe methods to ensure that the ACC works at very high efficiency and a high degree of homogeneity
[en] The high luminosity upgrade of the LHC is targeted to deliver 3000 fb−1 at a luminosity of 5×1034 cm−2 s−1. Higher granularity, 140 collisions per bunch crossing and existing bandwidth limitations require a reduction of the amount of data at module level. New modules have binary readout, on-chip discrimination and capabilities to provide track finding data at 40 MHz to the L1-trigger. The CMS collaboration has undertaken R&D effort to develop new planar sensors for the pixel-strip (PS) module, which has to withstand 1×1015 cm−2 1 MeV neutron equivalent fluence in the innermost layer of the tracker. The module is composed of a strip sensor and a macro pixel sensor with 100 μm×1.5 mm pixel size. Sensors were characterized in the laboratory and the effects of different process parameters and sensor concepts were studied. This contribution presents a new sensor prototype with n-pixels in p-bulk material in planar technology for the PS module. A new inverted module concept is presented, which has advantages with respect to the baseline concept. Electrical characterization of sensors and SEM-images are presented.
[en] The LHC machine is planning an upgrade program which will smoothly bring the luminosity to about around 2028, to possibly reach an integrated luminosity of 3000 fb−1 in the following decade. This High Luminosity LHC scenario, HL-LHC, will require a preparation program of the LHC detectors known as Phase-2 upgrade. The current CMS Outer Tracker, already running close to its design limits, will not be able to survive HL-LHC radiation conditions and CMS will need a completely new device, in order to fully exploit the highly demanding operating conditions and the delivered luminosity. The new Tracker should have also L1 trigger capabilities. To achieve such goals, R&D activities are ongoing to explore options and develop solutions that would allow including tracking information at Level-1. The design choices for the CMS Outer Tracker upgrades are discussed along with some highlights of the R&D activities.
[en] The CMS experiment at the CERN LHC includes a pixel system for tracking and vertexing charged particles. This system consists of two parts: the central and the forward detectors. This paper describes the main features of the forward detectors, which are being built by a collaboration of physicists from the USA. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)=20
[en] This is a short note to acknowledge the successful operation of a 140-cm drift liquid argon TPC built in the framework of the ICARUS experiment. We show few cosmic muon tracks crossing the whole drift volume from the wire planes to the cathode. Data were taken at drift fields of 450 and 500 V/cm