User name A. Deur
Log entry time 10:57:09 on August25,2003
Entry number 113450
This entry is a followup to: 112093
keyword=2-step process contamination for 4.4 GeVThe 2-step process for 4.4 GeV is very small. In fig 1 we show y_target for an empty ref cell run for kinematic 12.20 (the worst case) after good pid cuts (shower?pressower and Cerencov).
The central peak is made of electrons from the 2-step process. The 2 other peak are the windows. The central peak is made of electrons but it is likely that the 2 window peaks are made of the few pions that passed the pid cuts due to detector inneficienccies.
After removing the windows contribution, it appears that the 2 step contamination is 1 % for a pol 3He run.
FIGURE 1
