EVENT-FILTER

An event is retained by the DELANA event-filter if :

it is not tagged as a Bhabha in STIC.

AND if at least one of the following conditions is satisfied:

super team 1 selections:
- at least 4 charged tracks and Sum(E_ch). GT. 0.095 E_cm
- quality cuts on charged tracks: P .GT. 0.295 GeV/c , |IP_xy| .LT .10 cm , |IP_z| .LT. 20 cm , L. GT. 10 cm
gamma gamma team selections:
- at least 1 EM cluster (HPC+FEMC+STIC+VSAT) with E .GT. 0.2 E_cm , and at least 2 charged tracks ; if N_ch=2 then at least one track must have P .GE. 1 GeV/c
  .OR.
  
  at least 4 charged tracks, no EM clusters with E .GT. 0.2 E_cm, at least one charged track with P_t .GE. 1 GeV/c
  quality cuts on charged tracks: P .GT. 0.4 GeV , |IP_xy| .LT. 4 cm , |IP_z| .LT. 8 cm , L .GT. 30 cm , DP/P .LT. 1
soft events for degenerated searches 1:
- 2 or 3 charged tracks with a total sum |P_t| .GT. 3 GeV/c
- quality cuts on charged tracks: P .GT. 0.4 GeV/c , |IP_xy| .LT. 4 cm , |IP_z| .LT. 8 cm , L .GT. 30 cm , DP/P .LT. 1
soft events for degenerated searches 2:
- 2 to 10 charged tracks , at least 1 of these with P .GT. 1 GeV/c and theta > 30 deg , total P_t .GT. 4 GeV/c
- quality cuts on charged tracks: P .GT. 0.1 GeV/c , |IP_xy| .LT. 10 cm , |IP_z| .LT. 10 cm , L .GT. 10 cm , DP/P .LT. 1.5
single photon events:
- at least 1 cluster of 5 GeV in HPC or in FEMC
single lepton events:
- 1 or 2 charged tracks of which one has P .GT. 10 GeV/c
- quality cuts on charged tracks: P .GT .0.2 GeV/c , |IP_xy| .LT. 5 cm , |IP_z| .LT. 4/sin(theta) cm , L .GT. 15 cm
THADR-tag 1:
- (No. charged tracks P .GT. 10 GeV/c + No. HPC clusters E .GT. 10 GeV + No. FEMC clusters E .GT. 10 GeV ) .GE. 2
- quality cuts on charged tracks: |IP_xy| .LT. 5 cm , |IP_z| .LT. 10 cm , L .GT. 30 cm , theta . GT . 20 deg
THADR-tag 2:
- P_miss (all charged and neutrals) .GT. 10 GeV/c , theta_miss .GT. 20 deg , at least 3 selected tracks , sum(|P_sel|) .GT. 0.06 E_cm
- quality cuts on charged tracks: P .GT. 0.4 GeV/c , |IP_xy| .LT. 5 cm , |IP_z| .LT. 10 cm , L .GT. 30 cm , theta . GT . 20 deg
THADR-tag 3:
- at least 5 charged tracks with sum(|P|). GT. 0.12 E_cm
- quality cuts on charged tracks: P .GT. 0.4 GeV/c , |IP_xy| .LT. 5 cm , |IP_z| .LT. 10 cm , L .GT. 30 cm , theta . GT . 20 deg
THADR-tag 4:
- at least 2 charged tracks , at least 1 track with P .GT. 4.5 GeV/c
- quality cuts on charged tracks: P .GT. 0.4 GeV/c , |IP_xy| .LT. 5 cm , |IP_z| .LT. 10 cm , L .GT. 15 cm , theta . GT . 20 deg
THADR-tag 5:
- at least 5 charged tracks with sum(|P|). GT. 0.07 E_cm
- quality cuts on charged tracks: P .GT. 0.2 GeV/c , |IP_xy| .LT. 5 cm , |IP_z| .LT. 4/sin(theta) cm , L .GT. 15 cm
calibration events: A subsample of those events flagged by DELANA for detector calibration.
- mu+mu-. Less than 5 charged tracks in total , 2 tracks ( P .GT. 15 GeV/c , |IP_xy| .LT. 2 cm , |IP_z| .LT. 5 cm ) collinear to 10 deg.
- e+e-. Less than 5 charged tracks in total , 2 clusters in HPC or FEMC with E .GT. 15 GeV collinear to 10 deg.
- tau+tau-. Less than 7 charged tracks. Sum(E_ch) .GT. 8 GeV . Require at least 2 tracks with |IP_xy| .LT. 2 cm and |IP_z| .LT. 10 cm and all such tracks within 30 deg cones defined by the direction of the higest momentum track.
- gg -> ll. Exactly 2 charged tracks ( 1.LT.P.LT.20 GeV/c , |IP_xy| .LT. 6 cm , |IP_z| .LT. 10 cm ), one +ve one -ve and with sum(E) .LT. 20 GeV. If energy in STIC or VSAT , E .GT. 20 GeV for maximum energy shower. If no STIC or VSAT cluster, cos(theta+) + cos(theta-) .GT. 0.2
- Comptons. Criteria taken from HPC selection routines.

Last update 7 May 1999

For any problem/question contact :
John Wickens (John.Wickens@cern.ch)