Beam Position Determination using Tracks

Track-based algorithms to determine the LHC beam position and profile at the CMS collision point are described. Only track information is used and no reconstruction of the primary event vertex is required. With only about thousand tracks, a statistical precision of 2 microns for the transverse beam position is achieved, assuming a well aligned detector. The algorithms are simple and fast, and can be used to monitor the beam in real time. A method to determine the track impact parameter resolution using the beam position and beam width calculation is also presented.