Here is a figure showing errors projected for a 50 pb^(-1) measurement of double spin asymmetry.  The measurement is based on loose pi0 cuts (necessary for large pt) and on error=1/Sqrt[N]/Pol/Pol with N the number of events in a bin.  This result uses a 35 mR cone for two photon selection, with a minimal suppression of signal from the exclusive cut. 

The trigger from run 12 was FMS Jet Patch 2. It is this that defines the lower pT response and can be set to anything we choose. In Run 12 we used a Jet Patch 1 with prescaling to sample the distribution to lower pt (~ 1 GeV lower).  The pseudo-rapidy range is the full range of the FMS 2.7<Y<4.  

The data used was Day 60 from Run 12 with integrated luminosity of about 0.31 pb^(-1) and these result are scaled up from that to 50 pb^(-1). 

(This is incomplete)

The error plot above is based on the number of events per pb^(-1).  Those numbers are plotted below.

The following plot shows the number of pi0 events per 1 Gev bins per inverse pB of luminosity.
This is something with units (d sigma)/(dpT) or cross section per GeV/c.

Luminosities were taken from  (Run 12 Day 60) 
The values used were:

Run=13060005 Lum=0.023013 total=0.023013
Run=13060007 Lum=0.022290 total=0.045303
Run=13060008 Lum=0.041326 total=0.086628
Run=13060009 Lum=0.041052 total=0.127681
Run=13060010 Lum=0.002425 total=0.130106
Run=13060011 Lum=0.041800 total=0.171906
Run=13060012 Lum=0.032822 total=0.204727
Run=13060001 Lum=0.045992 total=0.250719
Run=13060002 Lum=0.044899 total=0.295618
Run=13060003 Lum=0.019476 total=0.315094


Sam Heppelmann's analysis of cone size dependence of Invariant Cross Section without acceptance correction.



The following plot is with soft energy within the specified cone size required to be small.


The following ploit is the same without cone size cut.