User name X. Zheng
Log entry time 03:46:00 on June14,2001
Entry number 63030
This entry is a followup to: 62893
keyword=delta, transverse asymmetryTwo plots for delta transverse asymmetry:
Top:
Prescale factors and live time for T1, T2, T3 and T4, with different helicities (+,-,0), are corrected by :
(number of events in histogram)/(total trigger from scalers)
I had a problem with T2 and T4. The prescale factors in epics data are 2 for all T1,T2,T3 and T4. But the numbers I extracted from histograms and scalers give T1/T3 ~ 2.1, T2/T4 ~ 3.2.
Bottom:
Prescale factors and live time for different helicities (+,-,0), are obtained from scalers:
(total accepted triggers)/(total triggers). T1 and T2 (or T3 and T4) have the same prescale factor + livetime.
It has been suggested that we do not count T2 and/or T4 to correct instrument inefficiency. However, for delta asymmetry, I did not observe big difference so they are not included here.
FIGURE 1
FIGURE 2
