User name A. Deur
Log entry time 01:19:49 on July29,2003
Entry number 107816
This entry is a followup to: 107568
keyword=12% "glass" contamination
Here a plot of en empty ref run (black)+production run (red) both for kinematics 5:13.
If I assume a perfect vacuum in the ref cell it appears that the contamination (with analysis cut) is 12%.
The bump at yt=0.006 can either be due to event that scattered off the Be window and then the glass wall (2 step process), which is the background that we are looking for, or from residual gas. So this 12% is an upper limit. Note that the elastic empty cell run shows also this bump (see entry 107568) while the 2 step process background is forbiden in the elastic kinematics. So for elastic, all the peak at yt=0.006 is from residual gas.