• Main INDEX
  • Monthly INDEX
  • PREV
  • NEXT

    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).

    FIGURE 1

    FIGURE 2