Alignment of the ATLAS Inner Detector Tracking System with 2010 LHC proton-proton collisions at $\sqrt{s}$ = 7 TeV

The ATLAS Inner Detector tracking system has been aligned for the analysis of the LHC √s = 7 TeV proton-proton collision data taken during 2010. The input data for the alignment consisted of two samples: one of high pT and isolated collision tracks, while the second comprises a sample of cosmic-ray tracks collected between LHC proton-proton collisions. The alignment approach used is a track-based algorithm that minimizes a χ2 based on track-hit residuals. This note presents the alignment procedure, its results and performance with the LHC collision data. Results from real data are compared with a Monte Carlo sample simulated with a perfectly aligned detector.