Takeshi K. Komatsubara
last update 2002-Apr-21

Figure-of-Merit of the charged-track trigger requirements

Kpi2(2)  KB  DC  IC-T2      L1.n  HEX

1gamma  Kpi2(2)    BV  

• This trigger accepts the events whose RS stopping layer is from 06 to 18. In the offline analysis, the stopping layer is restricted to be 11-18.
• The Figure-of-Merit (FoM) by changing the stopping-layer requirement (   , layer 06-18) was calculated with:

Kpi2(2)

triggers (Online Rejection) and
• simulation on E787-UMC (Acceptance).

• RR3  Refined Range for the kp23 trigger (to remove  ).
• The  trigger in E787-1991 was (in the E949 words):

KB  DC  IC-T2

  

Refined Range

L1.n  HEX    BV

• and

Lev1.5(RS Energy)  Lev3(photon clustering)


which do not exist in E949.

This trigger accepts the events whose RS stopping layer is from 15 to 18.
• ``Layer 16-17'' gives the best FoM.
• Skipping layer 15 removes almost all the  decays.
• Skipping layer 18 reduces the the  decays in the sample.

• RR3
• layer 14-18
• layer 15-18
• layer 16-18
• layer 16-17
• layer 15-18, RR3
• layer 15-17, RR3

 
        top left                         online stopping counter

bottom left Ptot (pi+ momentum)

bottom right Rtot (pi+ range) vs Ptot
 

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