Hi Flemming, I'm aware of the fact that the BB vtx is not always available for some systems. That's why I tried to keep the global track fit module as untouched as possible. The change I introduced is very simple, let me summarize : the only place in the FS tracking code where we evaluate the track vertex is the FFS tracking module. In the BFS tracking module, the track vertex is something different (origin of the BFS track at the front of the 1st tracking chamber - T2 or T3). SInce a full FS track is always a combination of an FFS track and BFS track, the track vertex will be what was done at the FFS level. The FFS tracking module has an option : use BB vtx or not. When the BB vtx is not used, then the global track refitter will act as before (reevaluate the vertex in the global plane x = 0). If the BB vtx was used, then the refitter will not change it. The question is : do we want to have the "track-beam" vertex also for AuAu while the BB vtx is more reliable ? Remember again that the refitter only sets the full fs track vertex, not the FFS, so that at the end you end up with comnpletely different vertices (FFS vs full FS) for the same physical track ... Djam -- Djamel Ouerdane ------------------------------------------o | Niels Bohr Institute | Home: | | Blegdamsvej 17, DK-2100 Ø | Jagtvej 141 2D, | | Fax: +45 35 32 50 16 | DK-2200 Copenhagen N | | Tel: +45 35 32 52 69 | +45 35 86 19 74 | | http://www.nbi.dk/~ouerdane | | ouerdane@nbi.dk | o---------------------------------------------------------o _______________________________________________ Brahms-dev-l mailing list Brahms-dev-l@lists.bnl.gov http://lists.bnl.gov/mailman/listinfo/brahms-dev-lReceived on Thu Jul 29 09:36:17 2004
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