1. Determine absolute luminosities for the runs used to calculate gamma yields

     a. Run list used in the analysis

     b. Jamie's bytrig.pl perl script used to sum up luminosities for each trigger, by each day, etc...

     $ bytrig.pl -s -f -r runlist.txt

 Result: trigger ID 137641 / aka EEMC L2gamma accumulated 4.3 pb^-1.  FOM is 0.27 pb^-1 based on online polarizations.

 

2.  For a luminosity of 4.3 pb^-1, how many events do we expect vs. pT?  First try a quick pythia simulation.

     a. Use pythia 8.1000

     b. Set min partonic pT = 4 GeV (to speed calculation)

     c. Select only direct gamma processes

     d. Count event if pT > 5 GeV and 1.05 < eta < 2.0

     e. Accumulate a sample of 6800 events

Result:  6800 events in EEmc above pT = 5 GeV for N_tried = 232468 σ = 1.557 times 10^-5 mb. Luminosity = 1.49 pb-1.

 

3. Extrapolate to pp2006 luminosity of 4.3pb^-1 determined above.

 

Jet "reconstruction" using pythia's jet finder, min ET = 5 GeV, cone radius = 0.7 and seed ET = 1.0 GeV.