Speaker
Denis Oliveira Damazio
(Brookhaven National Laboratory)
Description
The ATLAS detector is undergoing intense commissioning effort with
cosmic rays preparing for the first LHC colisions next spring. Combined
runs with all of the ATLAS subsystems are being taken in order to evaluate
the detector performance. This is an unique opportunity also for the trigger
system to be studied with different detector operation modes, such as
different event rates and detector configuration.
The ATLAS trigger starts with a hardware based system which tries to identify
detector regions where interesting physics objects may be
found (eg: large energy depositions in the calorimeter system).
An approved event will be further processed by more complex algorithms
at the second level where detailed features are extracted (full detector
granularity data for small portions of the detector is available). Events
accepted at this level will be reprocessed at the so-called event filter
level. Full detector data at full granularity is available for offline like
processing with complete calibration to achieve the final decision.
This year we could extend the experience by including more algorithms
at the second level and event filter calorimeter trigger. Clustering algorithms
for electrons, photons, taus, jets and missing transverse energy are being
commissioned during this combined run period. We report the latest results for
such algorithms. Issues such as hot calorimeter regions identification, processing
time for the algorithms, data access (specially at
the second level) are being evaluated. Intense usage of online and quasi-online
(during offline reconstruction of runs) monitoring helps to trace and fix problems.
| Presentation type (oral | poster) | oral |
|---|
Author
Denis Oliveira Damazio
(Brookhaven National Laboratory)
