Attendees: Ashot, Chao G, Chao P, Dipangkar, Eugene, Li, Maxime, Weizhi, Xinzhan.


Weizhi:
Simulation vs data comparison for ep and ee: showing 2.2 GeV 
Event selection uses HyCal for hits and position information from GEM.Stability of ep/ee ratio very good. ee integrated from 0.7 to 2 deg and ep from 0.7 to 1.3 deg
For the 1.3 to 3.5 deg angles the stability is even better likely because of smaller background.
For 3.5 and 5.2 deg the low current (25 nA) ratio is slightly lower.  
Looked at calibration as a cause but there was no smoking gun.

The bgd to signal ratio studied for ep and ee for different beam current, no non-linear effects observed.

The bgd to signal for different quadrants show a difference for ep at the lowest angles. (facing Hycal, 1st is top right and then go counter clockwise). 1st and 3rd are similar while 2nd and 4th are different with 2nd being the highest.

<TASK> check using simulation, try the different shifts in beam, collimator and
beam angles (if possible).


Maxime:
Independently looking at stability, still has some problem which is being investigated.
1.1 GeV seems to have a slope vs run number.

Chao:
Added two more cuts, cluster size cut and Chi-sq test cut. Results still being generated. Will show results next time.

Xinzhan:
Generating new set of offset tables since he found an error in the z-position.
Also working on cosmic rejection, developing own algorithm.

General discussion:
1. Need to have collaboration meeting before DNP. One possible time is beginning of Oct.
2. The Analysis note needs to be started.