User name R. Michaels
Log entry time 04:08:12 on December 20,1999
Entry number 31570
keyword=Why T2 and T4 are background
I think these plots show why T2 and T4 are probably mostly
due to a kind of background (or noise) which does not
correlate between two scintillators (i.e. hits one, not both).
If we suppose THIS KIND of background is proportional to rate, then
the random coincidence of two detectors required to get a T2 or T4
goes like (rate)^2. So the ratio T2/T1 should increase with
T1 rate, and similarly T4/T3. This is apparently what happened in
the past 35 hours of stable running (see fig 1 and 2).
One might imagine some sort of trigger deadtime effect for
the 100 kHz on H-arm, but this is impossible for the tiny 60 Hz
on the E-arm. So perhaps this is a proof that T2, T4 are
mostly backgrounds (with a small component of inefficiency).