Alignment results of LHC tracking detectors

We present the first results of the alignment of the vertex detectors of the LHC experiments based on the reconstructed tracks from the cosmic data taken during the commissioning runs with the detectors in their final positions. The unprecedented complexity of these detectors poses new challenges in aligning system with several thousands of silicon modules built in different technologies: strip, pixel, and silicon drift chambers. For optimal track-parameter resolution, the position and orientation of the modules need to be determined with a precision of few micrometers. The achieved resolution in all five track parameters is controlled with data-driven validation of the track parameter measurements near the interaction region, and tested against prediction with detailed detector simulation. Outlook for expected tracking performance with the first collisions is given.