The application of Hough transform for fast interaction vertex position estimation in heavy-ion collisions

Charged particle track reconstruction in silicon detectors of collider experiments in high-multiplicity events, such as heavy-ion collisions at LHC, is a difficult and resource-demanding process. The first phase of the procedure is the formation of seeds composed out of a few signals per track. A high number of actual particles results in a combinatorial explosion of the number of seeds. A priori knowledge of the collision vertex position would allow discarding non-viable track seeds early in the reconstruction procedure, reducing the overall computing requirements for the track reconstruction. The method proposed in this paper uses the Hough transform for estimating the position of the interaction vertex without the necessity of reconstructing the tracks first. It offers admissible resolution with linear scaling of numerical complexity with the multiplicity of tracks.