Kunihiro Nagano

Design studies of the ATLAS muon Level-1 trigger based on the MDT detector for the LHC upgrade

The present muon Level-1 trigger of the ATLAS detector is given by dedicated detectors; RPC and TGC chambers in barrel and end-cap regions, respectively. The Monitored Drift Tube (MDT) chambers and the Cathode-Strip Chambers (CSC) are used for precision measurements of muon tracks. The performance of the muon Level-1 trigger is limited by the momentum resolution of the trigger chambers. In order to improve the trigger performance, a muon track finding scheme based on MDT signals is envisaged. Studies of the scheme and the algorithm are presented. The trigger latency is estimated to be approximately 3 μs.

High-Q2 neutral- and charged-current reactions at HERA

Publisher Summary Deep inelastic scattering (DIS) of leptons on nuclei has been the key for our understanding of the structure of the nucleon. HERA at DESY is a unique facility of colliding electrons (or positrons) with protons. The HI and ZEUS experiments at HERA measured e + p deep inelastic scattering cross sections at high-Q 2 both for neutral-current and charged-current interactions using data taken during the 1994-1997 running periods. This chapter presents preliminary results of e - p deep inelastic scattering cross sections from the data taken during the recent 1998-1999 running period. Neutral current DIS events are required to have an isolated scattered electron with an energy greater than 11 (10) GeV in H1 and ZEUS analysis. The selection efficiency is on average 80% for ZEUS. The main source of background is due to photoproduction, that is, γρ interaction with photon virtuality nearly equal to zero. The background contamination is estimated to be less than 1% in overall kinematic region, and is statistically subtracted.