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Tracking news [message #6509] Thu, 17 April 2008 19:34 Go to next message
Sebastian Neubert is currently offline  Sebastian Neubert
Messages: 282
Registered: March 2006
Location: Munich
first-grade participant

From: *e18.physik.tu-muenchen.de
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]

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Re: Tracking news [message #6512 is a reply to message #6509] Fri, 18 April 2008 10:22 Go to previous messageGo to next message
asanchez is currently offline  asanchez
Messages: 350
Registered: March 2006
first-grade participant
From: *kph.uni-mainz.de
Hi Sebastian, you have done a great work!!
thanks a lot.

I have still a question not only for you,
what happen with low momenta particles
(<0.5 MeV) is Geane and genfit still dealing properly in this case?

again thanks a lot.
ALicia S.
Re: Tracking news [message #6514 is a reply to message #6512] Fri, 18 April 2008 10:28 Go to previous messageGo to next message
Sebastian Neubert is currently offline  Sebastian Neubert
Messages: 282
Registered: March 2006
Location: Munich
first-grade participant

From: *e18.physik.tu-muenchen.de
Hi Alicia!

Are that 0.5MeV or Gev???

I recently tried with 200MeV Protons and it did not work. But I did not look systematically so far.

Cheers! Seabstian.


Sebastian Neubert
Technische Universität München
Department Physik E18
sneubert@e18.physik.tu-muenchen.de
tel: +49-8928912592
Re: Tracking news [message #6515 is a reply to message #6514] Fri, 18 April 2008 10:48 Go to previous messageGo to next message
asanchez is currently offline  asanchez
Messages: 350
Registered: March 2006
first-grade participant
From: *kph.uni-mainz.de
Oh yes excuse me, <0.5 GeV.
Re: Tracking news [message #6525 is a reply to message #6515] Fri, 18 April 2008 12:43 Go to previous messageGo to next message
Lia Lavezzi
Messages: 291
Registered: May 2007
Location: Torino
first-grade participant

From: *PV.INFN.IT
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 Sad

Ciao,
Lia.

Re: Tracking news [message #6526 is a reply to message #6525] Fri, 18 April 2008 12:50 Go to previous messageGo to next message
asanchez is currently offline  asanchez
Messages: 350
Registered: March 2006
first-grade participant
From: *kph.uni-mainz.de
thanks a lot
ALicia S.
Re: Tracking news [message #6527 is a reply to message #6526] Fri, 18 April 2008 13:10 Go to previous messageGo to next message
Sebastian Neubert is currently offline  Sebastian Neubert
Messages: 282
Registered: March 2006
Location: Munich
first-grade participant

From: *e18.physik.tu-muenchen.de
Hi Lia!

What do you mean by "bending too much". Is this in relation to the step size?

I could imagine that maybe if we reduce the step size, then the bending should not be a problem. Should it?

Sebastian.


Sebastian Neubert
Technische Universität München
Department Physik E18
sneubert@e18.physik.tu-muenchen.de
tel: +49-8928912592
Re: Tracking news [message #6531 is a reply to message #6527] Fri, 18 April 2008 15:24 Go to previous message
Lia Lavezzi
Messages: 291
Registered: May 2007
Location: Torino
first-grade participant

From: *PV.INFN.IT
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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