ATLAS Inner Detector Performance

Two ATLAS reconstruction packages, iPatRec and xKalman, running within the ATHENA framework using software release 6.0.3, have been used to study the performance of the ATLAS Inner Detector. Two versions of the detector layout, have been used namely the version currently used for DC1 and the version foreseen for DC2. The response of the detector for single muons has been measured to obtain the track parameter resolution and quality. More realistic performance figures for the detector and a measurement of the pattern recognition capabilities of the algorithms have been obtained from a further study with di-quark jets, including pile-up. The results obtained with the two algorithms, and the two layouts have been compared. A comparison with the results presented in the Physics TDR has found some degradation in performance which is attributed to changes in the layout geometry and the addition of more material.