SSD and the SVT tracking methods SGR STK
Currently two different tracking methods exist in order to form track segments in the SVT. Both algorithms require that a particle leaves a hit in each SVT layer.

The SVT Grouper (SGR) is looking for groups of hits based on a global mapping technique (see STAR Note 0153). Originally it has been developped for a vertex detector with only 3 layers. The latest version of the code can be found here (under the directory pams/svt/sgr).

A work is currently in progress in order to adapt SGR to four layers and associate SSD hits to SVT hits.

The SVT Tracker (STK) is the main SVT tracking module (see STAR Note 0145). It is based on a "follow you nose" method which works reasonnably well for the SVT geometry. This module has been adapted to a vertex detector geometry including the SSD. With this geometry, the tracking performances are quite poor mainly due to the failure of the linear extrapolation of the tracks from the SVT to the SSD. Comparisons of tracking performances obtained with STK and an other tracking method (see below) with 3 and 4 silicon layers can be found in the SSD Proposal. The version of the module developped for the SSD has not been installed in the STAR Software library.

Last modified: Wed Jan 19 16:14:56 MET