Improved luminosity determination in pp collisions at sqrt(s) = 7 TeV using the ATLAS detector at the LHC

The luminosity calibration for the ATLAS detector at the LHC during pp collisions at in 2010 and 2011 is presented. Evaluation of the luminosity scale is performed using several luminosity-sensitive detectors, and comparisons are made of the long-term stability and accuracy of this calibration applied to the pp collisions at . A luminosity uncertainty of is obtained for the 47 pb(−1) of data delivered to ATLAS in 2010, and an uncertainty of is obtained for the 5.5 fb(−1) delivered in 2011.