SSD and the SVT tracking methods
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SGR
STK
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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