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


Ashot: Will share email from Doug H. about checking Xuefei and Weizhi's fitting programs with pseudo data. Xuefei will work on this.


Weizhi: 
completed: inelastic, GEM eff, HyCal trig eff.

in progress: generator comparison, simulation near transition region, coordinate
reconstruction of HyCal

problems: large slope in (ep/ee)_sim /(ep/ee)_data, discrepancy for theta>3.5

The old GEM z and new GEM z are different and the slope in sim/data double ratio is very sensitive to this. Showed various tests with GEM z shifted.
Looking into run-by-run variation of GEM z position. It is also energy dependent. 

Need to know the survey plane.

The difference between old and new slope seems to all from the GEM z position.

The inelastic contribution has a sharp rise as one moves from PWO to LG modules

The difference between data and simulation has some structure under the elastic peak for large angles. The structure seems to point to an offset between data and simulation and also difference between the widths.

Since the discrepancy seems to be from elastic events need to look into the ep event generator for clues.

There are some discrepancies between the Gramolin event generator and Chao G generator, these are being studied.


Current cross sections from 50% of 2.2 GeV data was presented, with total syst errors of about 1.5%

very preliminary estimation of radius was also presented

Effort is needed in pushing the checking of the generators.

Maxime:
Theta resolution and HyCal reconstruction

sigma of (Theta_GEM - Theta_Sim) = 0.0025 deg

The dependence of x-reconstruction on logarithm weight parameter alpha 
studied.

Correction of hycal coordinate by profile inversion (on progress)