21-25 August 2017
University of Washington, Seattle
US/Pacific timezone

The ATLAS Trigger Simulation with Legacy Software

22 Aug 2017, 16:00
The Commons (Alder Hall)

The Commons

Alder Hall

Poster Track 2: Data Analysis - Algorithms and Tools Poster Session


Adam Edward Barton (Lancaster University (GB))


Physics analyses at the LHC which search for rare physics processes or
measure Standard Model parameters with high precision require accurate
simulations of the detector response and the event selection
processes. The accurate simulation of the trigger response is crucial
for determination of overall selection efficiencies and signal
sensitivities. For the generation and the reconstruction of simulated
event data, generally the most recent software releases are used to
ensure the best agreement between simulated data and real data. For
the simulation of the trigger selection process, however, the same
software release with which real data were taken should be ideally
used. This requires potentially running with software dating many
years back, the so-called legacy software. Therefore having a strategy
for running legacy software in a modern environment becomes essential
when data simulated for past years start to present a sizeable
fraction of the total. The requirements and possibilities for such a
simulation scheme within the ATLAS software framework were examined
and a proof-of-concept simulation chain has been successfully
implemented. One of the greatest challenges was the choice of a data
format which promises long term compatibility with old and new
software releases. Over the time periods envisaged, data format
incompatibilities are also likely to emerge in databases and other
external support services. Software availability may become an issue,
when e.g. the support for the underlying operating system might
stop. The encountered problems and developed solutions will be
presented, and proposals for future development will be
discussed. Some ideas reach beyond the retrospective trigger
simulation scheme in ATLAS as they also touch more generally aspects
of data preservation.

Primary authors

Catrin Bernius (SLAC National Accelerator Laboratory (US)) Adam Edward Barton (Lancaster University (GB))

Presentation materials

Peer reviewing