GSI Forum
GSI Helmholtzzentrum für Schwerionenforschung

Home » PANDA » PandaRoot » Tracking » back-propagation with GEANE
Re: back-propagation with GEANE [message #10737 is a reply to message #10732] Tue, 25 May 2010 14:57 Go to previous messageGo to previous message
Anastasia Karavdina is currently offline  Anastasia Karavdina
Messages: 76
Registered: May 2010
Location: Mainz, Germany
continuous participant

From: *kph.uni-mainz.de
Hi Lia and Alberto,
I'm simulating antiprotons from the IP (0, 0, 0) with beam momentum 8.9 GeV/c in angles range (2,9) mrad for theta and (0,2*Pi) for phi angle.
The luminosity monitor is placed at 11 m downstream in z direction and z axis of the luminosity monitor is rotated for 2.33 degrees at 4.76 m. So it should be placed close to beam pipe.
But in my simulation I switched off beam pipe and I don't have any material before first plane of the luminosity detector.
You are right, in absence of magnetic field differences in my plots are very small. But as I don't have any material I can explain these differences only in two ways:
a) It's accuracy of calculation methods used in GEANE.
b) I did something wrong.
Differences in absence of magnetic field are not important I've asked you just to be sure that I used GEANE correct Rolling Eyes

In magnetic field situation become worse: I have difference 2*10^-3 rad for phi angle an 7*10^-6 rad for theta angle. From multiple scattering I expect uncertainties about 6*10^-5 rad for this beam momentum and for phi angle I obtained much more difference. Also I worried about two spots in plot of momentum magnitude (Delta P(P_MC) in file uncer.eps from my first post). Here Delta P is a difference between true simulation value P_MC and magnitude of momentum obtained after back-propagation. Do you know any reason why I obtained two different value for momentum magnitude after back-propagation?

Cheers,
Anastasia.
 
Read Message icon5.gif
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: [FIXED]A crash in reco
Next Topic: [ERRATA] STT plots from last collaboration meeeting
Goto Forum:
  


Current Time: Tue Apr 16 12:34:43 CEST 2024

Total time taken to generate the page: 0.00977 seconds