Vertex reconstruction and tracking in the trigger algorithm for CMS

Triggering in the high-rate environment of LHC is a challenging task. The Compact Muon Solenoid (CMS) experiment has developed a two-stage trigger system. The Level-1 Trigger is based on custom hardware devices while the High-Level Trigger (HLT) is using a farm of commercial processors. One of the key aspects of HLT reconstruction is a fast and efficient track and vertex finding, in which CMS Pixel Detector, the innermost in the tracking system, is of primary importance. It provides precise measurements not only supporting the full track reconstruction, but also allowing the standalone reconstruction which is well suited for CMS online selection. The track and vertex reconstruction algorithms for HLT are presented with a focus on fast pixel track reconstruction, primary-vertex finding and seed generation