Ilya's photon-jet reconstruction algorithm : 

Fiducial Cuts:

(i) Select dijet events identified by the STAR jet finder algorithm

(ii) Jet detector eta < abs(0.8) 

(iii) Photon in the endcap

(iv) Photon and jet opposite in phi i.e cos(phi_{gamma -} phijet  )< -0.8

(v) p_T  of photon > 7GeV

(vi) |vz  | < 100cm

Total number of events = 1457+4302+21628+27962 = 55349 (all preshower bins combined)

Plots picked up from Ilya's blog entry http://drupal.star.bnl.gov/STAR/node/13276

Trees numbers

How does the code work?

Analyzes dijets from the jet trees with an associated gamma to one of the jets from the gamma trees

Jets are associated with vertices. This code runs over jets with the vertex of highest rank. 12 point branch is used for this analysis.

Finds number of jets associated with this vertex

Applies z vertex cut : -100<z<100

Selects events having 1 photon and 2 jets

Loops over the jets to see if gamma candidate matches to any jet within a maximum radius of 0.7

If the gamma candidate is not in the endcap, rejects that event

Finds the away side jet by requiring cos(φγ – φjet) < -0.8

Requires pT of photon > 7GeV

Total number of events = 99553 (please see the following blog entry for this number)

http://drupal.star.bnl.gov/STAR/blog/sdhamija/2011/feb/13/run6-gammajet-plots-revised-with-additional-cuts