Trigger efficiency for high-pT electrons

 The plots below were mede from a few thousand single-electron AODs from 12.0.6 reconstruction. The data samples used were: 7005 (Et=120GeV), 7006 (Et=120GeV), 7007 (Et=500GeV), and 7009 (Et=1TeV).  The efficiency for the e25i and e60 signatures was plotted versus the offline electron eta, assuming at most one reconstructed electron per event. In practice there were 185, 56, 34 and 16 events in samples 7005, 7006, 7007 and 7009 where 2 electrons (never 3) were reconstructed. This was considered negligible. The efficiency was obtained directly from the TriggerDecision object and normalised to the offline "loose electron" selection. I.e. for each signature, or combination of signatures, the efficiency was calculated as the number of events which passed the trigger signature and where a loose electron candidate had been found, divided by the number of events where a loose electron candidate had been found. The only selection applied to the events was the loose electron selection ( (isEM & 0x7) ==0 ). The numbers of events analysed for each sample can be found in the log files (see table). They were:  ET=60GeV:  45950 analysed (41006 had electron candidates); ET=120GeV:  19000 analysed (16727 had electron candidates); ET = 500 GeV: 41500 analysed (31484 had electron candidates); ET = 1 TeV: 20500 analysed (14210 had electron candidates).

A small Athena algorithm was used to produce a reduced TTree. A ROOT macro was used to run on this TTree and produce the plots. Both Athena code and ROOT macro are in the Atlas cvs repository at:
users/jgoncalo/TrigEgammaPerformanceR12/TrigEgammaPerformanceR12-00-00-05


The table below has links to the plots:

 7005 (ET = 60 GeV) : log
 7006 (ET = 120 GeV) : log
 7007 (ET = 500 GeV) : log 7009 (ET = 1 TeV) : log Combined : Eff.vs.ET
e25i
 eps, gif
 eps, gif
 eps, gif
 eps, gif
 eps, gif
e60
 eps, gif eps, gif
 eps, gif
 eps, gif
 eps, gif

These plots shows the overall trend versus ET:
e25i efficiency wrt offline (rel.12)
 e60 efficiency wrt offline (rel.12)

For reference, the CSC-EG-11 note documentation is the cvs repository at: /groups/egamma/CSC-EG-11.
A previous version of this page is here

RG - last modified 12/12/07