| Tracking news [message #6509] |
Thu, 17 April 2008 19:34  |
Sebastian Neubert
Messages: 282
Registered: March 2006
Location: Munich
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first-grade participant |
From: *e18.physik.tu-muenchen.de
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Hi!
I have checked in new things for the tracking.
- GeaneTrackRep now takes account of the particle hypothesis - you have to give the pdgcode in the ctor
- GeaneTrackRep makes a guess wether it will do a propagation along the momentum vector or a backward propagation(!)
- GeaneTrackRep is using the geane tools to extrapolate to a point of closest approach. (See for example DemoToolsTask)
- Debug output has been cleaned up a bit.
For this you have to update more or less all tracking packages: genfit, geane, trackrep and
recotasks.
I would be glad to hear from you if these things work!
Best Regards! Sebastian.
Sebastian Neubert
Technische Universität München
Department Physik E18
sneubert@e18.physik.tu-muenchen.de
tel: +49-8928912592
[Updated on: Thu, 17 April 2008 19:34] Report message to a moderator |
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| Re: Tracking news [message #6525 is a reply to message #6515] |
Fri, 18 April 2008 12:43  |
Lia Lavezzi
Messages: 291
Registered: May 2007
Location: Torino
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first-grade participant |
From: *PV.INFN.IT
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Hi Alicia,
concerning GEANE, unfortunately, there is still the problem of low momenta (sorry about that).
Its limit value is not fixed (for example I remeber I tracked down to 300 MeV), but as you go down with the momentum the probability of having some event with a track which begins to bend too much or has a momentum which fades to zero raises: these are the cases when a flag is returned (the well known IERR error from the FORTRAN) and the code crashes. We are thinking about bringing this flag to the interface, so that the crash can be avoided using this information.
Anyway, when the code does not crash, the results of GEANE are reliable: the problem with low momentum particles is only the crash, since when the track bends too much within a single step or has 0 momentum GEANE stops because it does not know how to go on.
So you can try to run your low momentum events: if you don' t fall in one of the mentioned cases everything should work properly, but consider that if the momentum is too small the probability to avoid these problems is small too 
Ciao,
Lia.
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| Re: Tracking news [message #6531 is a reply to message #6527] |
Fri, 18 April 2008 15:24 |
Lia Lavezzi
Messages: 291
Registered: May 2007
Location: Torino
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first-grade participant |
From: *PV.INFN.IT
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Hi Sebastian,
yes, concerning the bending problem it should actually be connected to the step size.
You can have a look to the discussion "Problem with low momentum Pion" in this forum: it was related to the GEANE crash due to this kind of error.
A reduction in the step size fixed this problem, but obviously it will increase the computing time.
Ciao,
Lia.
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