For my relative luminosity calculations I use Tai's relative luminosity file that was released on June 14th, 2007.

• Luminosity File

I read this using the StTamuRelLum class, which, given a run number and BBC timebin, reads in the raw scalar values for each spinbit.  Each event is assigned raw scalar counts for each spinbit and every event from the same run with the same timebin should have the same scalar counts assigned.  When it comes time to calculate my asymmetry, the relative luminosity is calculated from these scalar counts.