Principal triggers for electrons (10 menu)

L1 L2 EF
L1_EM5 L2_e10_medium EF_e10_medium
L1_EM14 L2_e20_loose EF_e20_loose
L1_EM85 L2_em105_passHLT EF_em105_passHLT
L1_2EM3 L2_2e5_medium EF_2e5_medium

Trigger Hypos

In general, the following requirements must be passed:

L1:
  • EM ET: a 2x1 or 1x2-tower EM cluster, used to measure the ET of EM showers. There are four such regions within the RoI cluster, and the most energetic of these is used, EM ET > threshold
  • a 2x2-tower EM cluster, used to identify the position of candidate RoIs (local ET maximum)

L2 (eta dependent, shower shape variables):
  • The transverse energy ET calculated using the energies of all the electromagnetic-calorimeter layers in a Delta Eta x Delta Phi =3 x 7 standard cell area within the L1 RoI (standard cells cover an area of Delta Eta x Delta Phi ~ 0.025 x 0.025). Note, currently the ET is not corrected for leakage outside the cluster.
  • The hadronic transverse energy EThad within Delta Eta x Delta Phi =0.2 x 0.2.
  • The ratio Rcore = E37/E77, of energy contained in a Delta Eta x Delta Phi =3 x 7 window to that in a 7 x 7 window in the second sampling of the EM Calorimeter.
  • The fractional difference in energy between the strip with the maximum energy E1, and the second maximum E2, in the first sampling of the EM Calorimeter. The fraction is calculated as Eratio = (E1 - E2)/(E1 + E2).

L2, ID (eta dependent, track matching):

  • only tracks above a given energy are considered
  • ET/pT of the cluster transverse energy and the pT of the track are compared
  • Difference in phi between the cluster phi and the extrapolated track to the calorimeter surface
  • Difference in eta between the cluster eta and the extrapolated track to the calorimeter surface

EF (eta bins, pt bins depending on the threshold of the trigger):
  • The transverse energy ET calculated using the energies of all the electromagnetic-calorimeter layers in a Delta Eta x Delta Phi =3 x 7
  • ET/pT of the cluster transverse energy and the pT of the track
  • Difference in phi between the cluster phi and the extrapolated track to the calorimeter surface
  • Difference in eta between the cluster eta and the extrapolated track to the calorimeter surface
  • Fraction of high threshold TR hits compared to TRT hits associated with the track

  • use isEM flag

Tag and Probe

Links

-- SarahHeim - 20 Apr 2010
Topic revision: r2 - 22 Apr 2010, SarahHeim
 

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