2pion events produced by Witek PAT framework. Roo files with n-tuple including pi+pi- reconstruction is placed

/hera/hades/user/przygoda/PAT2/out/exp/186/hadron186.root

From 46 MLN events around 200 k di-pion pairs were reconstructed after simple pid cuts on clearly visible pions

in mass vs momentum correlation (see below- b.t.w note very clear electron contribution)
  • positive_PID:
    positive_pid.gif

  • negative_pid:
    negative_pid.gif
Momentum and polar angle distributions of negative and positive pions are presented below (due to the reversed polarity of the magnetic field negative pions are bent to smaller angles)

  • theta_distributions:
    pip_pim_ID_theta.gif

  • momentum distributions:
    pip_pim_ID_mon.gif

  • Event vertex distribution:
    ev_vertex_z.gif
From the simulation done for pion experiment one can estimate number of expected di-pion (see presentation

in https://hades-wiki.gsi.de/foswiki/bin/view/Meetings/HadesPion28052014

For 1MLN pion emerging from last Q9 we expect rougly 8-10% M2&&START triggers which corresponds to 100k events and around 350 di-pion pairs (for 7% tungsten target-rougly 7 times more than for LH2)

For the 46 MLN collected events we should then expect 160k pions

We see 200k, which looks quite fine
Topic attachments
I Attachment Action Size Date Who Comment
ev_vertex_z.gifgif ev_vertex_z.gif manage 4.8 K 07 Jul 2014 - 08:01 PiotrSalabura Event vertex distribution
negative_pid.gifgif negative_pid.gif manage 8.9 K 07 Jul 2014 - 07:56 PiotrSalabura negative_pid
pip_pim_ID_mon.gifgif pip_pim_ID_mon.gif manage 4.8 K 07 Jul 2014 - 08:00 PiotrSalabura momentum distributions
pip_pim_ID_theta.gifgif pip_pim_ID_theta.gif manage 6.3 K 07 Jul 2014 - 08:00 PiotrSalabura theta_distributions
positive_pid.gifgif positive_pid.gif manage 11.4 K 07 Jul 2014 - 07:56 PiotrSalabura positive_PID
Topic revision: r1 - 07 Jul 2014, PiotrSalabura
 
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