Impact of CMS silicon tracker misalignment on track and vertex reconstruction

The alignment uncertainties of the CMS tracker detector, made of a huge amount of independent silicon sensors with an excellent position resolution, affect the performances of the track reconstruction, the track parameters measurement and the vertex reconstruction. In order to study the impact of the misalignment of the CMS tracking devices on the previous procedures, realistic estimates for the expected displacements of the tracking systems are supplied in two different scenarios, the first supposed to reproduce the misalignment conditions during the first data taking while the second one related to long-term data taking condition. Results on the track reconstruction are expressed in terms of the resolution on track parameters, the global efficiency of the track reconstruction and the fake rate in the two scenarios of misalignment, by comparing them with the scenario of a perfect alignment of the tracking devices. Primary vertex finding efficiency and position resolution are affected by the tracker misalignment, too.