Abstract

The ATLAS experiment at CERN's Large Hadron Collider (LHC) has taken its first data with colliding beams. The LHC aims to deliver an integrated luminosity of 1 fb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> in the run period 2010/2011 at luminosities of up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">32</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> s <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> , which requires active rejection of events in the trigger system. The muon system is the largest sub-detector of the ATLAS experiment and has the capability to reconstruct muons in standalone mode, as well as in combination with the Inner Detector tracking. It deploys different detector technologies, resistive plate chambers and thin gap chambers to provide fast trigger signals, and monitored drift tubes and cathode strip chambers for precision measurements. The muon trigger system has been extensively tested with muons from cosmic rays and collision data taken in 2009/2010 at centre of mass energies of 900 GeV and 7 TeV. Results are presented for efficiency, resolution and general performance of the algorithms and detectors. The increasing data set with colliding beams at 7 TeV will allow the final commissioning of the muon trigger system. The strategy towards active selection in the HLT with the increasing luminosity profile of the LHC will be described.

Highlights

  • ObjecAve: Muon idenAficaAon in a wide momentum range from GeV (Onia) to TeV (BSM)

  • – Inner Detector (ID) track is matched to Muon Spectrometer Standalone (MS) segments

  • – ID track is matched to a MIP in calorimeter

Read more

Summary

Muon ReconstrucAon

ObjecAve: Muon idenAficaAon in a wide momentum range from GeV (Onia) to TeV (BSM). Make use of all detector components and use different strategies:. ObjecAve: Reduce from 40 MHz bunch crossing rate to ~200 Hz event rate to tape. – ReconstrucAon based on muon detectors only or in combinaAon with inner detector tracks for both L2 and EF available. – Require coincidence in eta phi view. – pT esAmaAon based on geometrical roads – Require coincidence in eta phi view. – pT esAmaAon based on geometrical roads

Performance measurement
Trigger Rates and EvoluAon
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call