0000000000647738
AUTHOR
S. Wada
Potential of the atmospheric monitoring system of JEM-EUSO mission
The existance of high energy particles with energies >1020 eV in the space is a basic problem in fundermental physics, because it means a violation of the GZK theoretical limitation. JEM-EUSO will try to detect such high energy particles in the space by the oprical fluorescence from the high energy paticles incident to the atmosphere. For caliblation of the optical background an atmospheric monitoring system consisting of a spaceborne lidar with an ultraviolet pulsed laser and an IR camera will be used. The IR camera takes images at suitable time intervals, monitoring the cloud cover in the whole field of view (FoV) of the telescope. Moreover stereo images are also taken to retrieve pixel b…
Performance of the upgraded PreProcessor of the ATLAS Level-1 Calorimeter Trigger
The PreProcessor of the ATLAS Level-1 Calorimeter Trigger prepares the analogue trigger signals sent from the ATLAS calorimeters by digitising, synchronising, and calibrating them to reconstruct transverse energy deposits, which are then used in further processing to identify event features. During the first long shutdown of the LHC from 2013 to 2014, the central components of the PreProcessor, the Multichip Modules, were replaced by upgraded versions that feature modern ADC and FPGA technology to ensure optimal performance in the high pile-up environment of LHC Run 2. This paper describes the features of the newMultichip Modules along with the improvements to the signal processing achieved.
Observation and Measurement of Forward Proton Scattering in Association with Lepton Pairs Produced via the Photon Fusion Mechanism at ATLAS
The observation of forward proton scattering in association with lepton pairs (eþe− þ p or μþμ− þ p) produced via photon fusion is presented. The scattered proton is detected by the ATLAS Forward Proton spectrometer, while the leptons are reconstructed by the central ATLAS detector. Proton-proton collision data recorded in 2017 at a center-of-mass energy of ffiffiffi s p ¼ 13 TeV are analyzed, corresponding to an integrated luminosity of 14.6 fb−1. A total of 57 (123) candidates in the ee þ p (μμ þ p) final state are selected, allowing the background-only hypothesis to be rejected with a significance exceeding 5 standard deviations in each channel. Proton-tagging techniques are introduced f…