Tracking system of the upgraded LHCb Obłąkowska-Mucha, A.; Szumlak, T.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Volume:
824
Journal Article
Peer reviewed
The upgrade of the LHCb experiment will run at an instantaneous luminosity up to 2×1033cm−2s−1 with a fully software based trigger, allowing us to read out the detector at a rate of 40MHz. For this ...purpose, the full tracking system will be newly developed: the vertex locator (VELO) will be replaced by a pixel-based detector providing an excellent track reconstruction with an efficiency of above 99%. Upstream of the magnet, a silicon micro-strip detector with a high granularity and an improved acceptance, called the Upstream Tracker (UT) will be placed. The tracking system downstream of the magnet will be replaced by the Scintillating Fibre tracker (SciFi), which will consist of 12 layers using 2.5m long scintillating fibres read out by silicon photo-multipliers.
LHCb is a dedicated experiment to study New Physics in the decays of heavy hadrons at the Large Hadron Collider (LHC) at CERN. Heavy hadrons are identified through their flight distance in the Vertex ...Locator (VELO). The VELO comprises 42 modules made of two n+-on-n 300μm thick half-disc silicon sensors with R- and Φ-measuring micro-strips. In order to allow retracting the detector, the VELO is installed as two movable halves containing 21 modules each. The detectors are operated in a secondary vacuum and are cooled by a bi-phase CO2 cooling system. During data taking in LHC Run 1 the LHCb VELO has operated with an extremely high efficiency and excellent performance. The track finding efficiency is typically greater than 98%. An impact parameter resolution of less than 35μm is achieved for particles with transverse momentum greater than 1GeV/c. An overview of all important performance parameters will be given. The VELO sensors have received a large and non-uniform radiation dose of up to 1.2×10141MeV neutron equivalent cm−2 during the first LHC run. Silicon type-inversion has been observed in regions close to the interaction point. The preparations for LHC Run 2 are well under way and the VELO has already recorded tracks from injection line tests. The current status and plans for new operational procedures addressing the non-uniform radiation damage are shortly discussed.
The LHCb detector is a single-arm forward spectrometer that collects data at the LHC, designed for studies of flavour physics with high precision. We present a selection of recent measurements of ...mixing and CP-violating parameters, including sin 2β and weak phase φ s, using several decays. A good understanding of the pollution from sub-leading penguin to pologies in these measurements can be achieved by measuring CP violation and polarization in the decay Bs0→Jψ⁄K0* and B0→Jψ⁄ ρ0. All results here presented are obtained using the full Run I dataset.
Ultra-fast silicon detectors (UFSD) are a specialized type of radiation detectors based on Low Gain Avalanche Detectors (LGADs) that are designed to have extremely fast response times. This work ...presents detailed results on the study of 50μm thin-LGADs with different doping concentrations produced by Micron Semiconductors Ltd. A temperature dependent study of electrical characteristics and infrared laser measurements are presented in this work.
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