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:
  

• negative_pid:
  

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:
  

• momentum distributions:
  

• Event vertex distribution:
  

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