Energy calibration and resolution of the CMS electromagnetic calorimeter in pp collisions at √s = 7 TeV
Abstract
The energy calibration and resolution of the electromagnetic calorimeter (ECAL) of the CMS detector have been determined using proton-proton collision data from LHC operation in 2010 and 2011 at a centre-of-mass energy of √s = 7 TeV with integrated luminosities of about 5\fbinv. Crucial aspects of detector operation, such as the environmental stability, alignment, and synchronization, are presented. The in-situ calibration procedures are discussed in detail and include the maintenance of the calibration in the challenging radiation environment inside the CMS detector. The energy resolution for electrons from Z-boson decays is better than 2% in the central region of the ECAL barrel (for pseudorapidity |η| < 0.8) and is 2–5% elsewhere. The derived energy resolution for photons from 125 GeV Higgs boson decays varies across the barrel from 1.1% to 2.6% and from 2.2% to 5% in the endcaps. The calibration of the absolute energy is determined from Z→e+e− decays to a precision of 0.4% in the barrel and 0.8% in the endcaps. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000074404Publication status
publishedExternal links
Journal / series
Journal of InstrumentationVolume
Pages / Article No.
Publisher
IOP PublishingSubject
Gamma detectors (scintillators, CZT, HPG, HgI etc); Calorimeters; Large detector systems for particle and astroparticle physicsOrganisational unit
03381 - Pauss, Felicitas (emeritus)
03593 - Dissertori, Günther / Dissertori, Günther
03904 - Wallny, Rainer / Wallny, Rainer
08803 - Grab, Christoph (Tit.Prof.)
Notes
Received 9 June 2013, Accepted for publication 8 August 2013, Published 19 September 2013.More
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