Attendees: Ashot, Chao G, Chao P, Dipangkar, Haiyan, Maxime, Nilanga, Weizhi, Xinzhan.


Maxime:
Started to compare 1.1 GeV data vs simulation, still using 2.2 GeV calibration 
constants. Waiting to implement new constants from Weizhi.

Ratio of cross sections for 2 GeV has wriggles which are from the simulations, will try to fix. Need to look into the numerical precision of the rad. correction code.

5% difference at 1 GeV which is from the old constants, will get fixed when the new constants are used.

<TASK> Investigate all differences observed

Xinzhan:
First application of the Duke cosmic removal algorithm. Seems to be too strict and removes most events at large angles.  
<TASK> investigate large angles for mis-identified good ep events.

Studied GEM efficiency with new very strict spacer cut to ensure only good areas are included. Also remove high-voltage dead areas. 
Overall the GEM coordinate correlation plots look good but a small fraction of events fall on the tails of these distribution which need to be understood.

Hycal cluster is still used to define search radius so there are Hycal resolution differences between 1 and 2 GeV data that can be seen in the efficiency and correlation plots.

The cleaned events efficiency has a slope vs angle which needs to understood, some of it may be related to cosmics. Other concerns are the small energy dependence and the ep vs ee differences.

Not much difference between 6 sigma and 10 sigma matching radius.


Weizhi:
Testing new generator with different parameters, the results are stable compared the generator used in the 2 GeV analysis (for small changes in the parameters).
  
<TASK> There is a third generator which needs to be tested too.


Also discuss slides for user group meeting.