1. determine bunch crossing offset by matching FMS event rate with fill pattern (wcm.dat), on a fill-by-fill basis.

    Fill 15315. Yellow offset = 80 ( (STAR bunchid+80)%120 = global bunch id in pol. pattern ), Blue offset = 0

2. number of clusters for each spin configuration:                                                            old spin bits with wrong yellow offset      

make raw correction to relative luminosity: blue up / blue down = 0.94

3. 2-photon cluster energy distribution:

                                                             uncorrected  

                                                                   corrected      

4. 2-photon cluster energy, pion candidates:

                                                                uncorrected    

 
                                                                  corrected  

5. left vs right: