Lia Lavezzi Messages: 291 Registered: May 2007 Location: Torino
first-grade participant
From: *pv.infn.it
Quote:
is it correct that the geane check on a track is the requirement to have momentum of last track point>0.1 (=100MeV/c)?
Then, what happens for very very low momentum particles: are they skipped and not fitted at all?
The cut @ 100 MeV/c was put in the Kalman fitting procedure because at the beginning there were some instabilities of geane. The code sometimes used to crash at very low momentum. In principle these instabilities should be fixed now, but I don' t think anyone ever tested the code without the cut and with high statistics.
Anyway, the cut on 100 MeV/c is not only in the pid, as I was saying, it is also inside the Kalman procedure, so the tracks are fitted only above that limit now.
Maybe we should test the code without this cut, but keeping the momentum > 0 obviously!
Lia.