Trigger Efficiencies - General Ways to Measure

Tag and Probe

• Using a single-object inclusive trigger, study di-object events: one selected online and one reconstructed. Study the trigger response for the second object that was not used for the online selection.
  • e.g. τ trigger efficiency from Z→ττ events.

Using an independent sample

• Study the efficiency of a trigger chain using events triggers with an orthogonal chain
  • e.g. study electron triggers using events trigger with muon triggers

Bootstrap method

• The efficiency, ε_B, of a trigger chain B, with higher thresholds than a trigger chain A, can be determined in a sample of events triggered by A, as ε_B|A. This works if the efficiency of A, ε_A, is measurable with some other method, and can be used for 'unfolding' ε_B|A to ε_B:

ε_B = ε_B|Axε_A