GSI Forum
GSI Helmholtzzentrum für Schwerionenforschung

Home » PANDA » PandaRoot » Analysis » Efficiency reduction of antiprotons above 20 degrees
Efficiency reduction of antiprotons above 20 degrees [message #17581] Tue, 25 November 2014 16:35 Go to previous message
Karin Schönning
Messages: 65
Registered: August 2012
Location: Uppsala University
continuous participant
From: *physics.uu.se
Dear Pandaroot experts,

there is an efficiency loss of antiprotons above a lab polar angle of 20 degrees in all hyperon channels I had a look at so far. To avoid any other kind of systematics I (after advice from Stefano) generated a sample of pbar p -> Lambdabar Lambda at 1.64 GeV/c with an isotropic angular distribution of the Lambda/Lambdabar. The problem remains, as you can see in the attached figures.
th_p_pbar.pdf shows theta (lab polar angle) vs the lab momentum of the antiproton, whereas th_p_proton.pdf is the same but for the proton.
Furthermore, there is an non-negligible difference in the pi- and pi- yields: 74% for pi- while 65% for pi+.

What could be the reason for this? Interaction of the antiproton with the detector material or some artifact of the tracking?

Kindest regards,
/Karin
 
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: No back propagation to IP for V_0 reconstruction
Next Topic: True vertex position for secondary decay vertices
Goto Forum:
  


Current Time: Sat Nov 02 23:14:55 CET 2024

Total time taken to generate the page: 0.00800 seconds