Primary Vertex Reconstruction at LHCb

The paper describes the algorithm for the primary vertex finding in the offline reconstruction of the LHCb data. The reconstruction is performed in two steps: seeding and fitting. In the first step the primary vertex candidates are selected by searching for the space points where an accumulation of track trajectories may be observed. In the second step the weighted least square method is employed to find the final vertex position. The performance of the primary vertex reconstruction is presented.