May 26 – 30, 2008
Biblioteca Universitaria, Pavia, Italy
Europe/Rome timezone

Fast shower simulation in ATLAS Calorimeter

May 29, 2008, 5:20 PM
Salone Teresiano (Biblioteca Universitaria, Pavia, Italy)

Salone Teresiano

Biblioteca Universitaria, Pavia, Italy

Strada Nuova, 65
oral presentation Simulation Simulation


Dr Ringaile Placakyte (DESY)


The simulation of the ATLAS detector is largely dominated by the
showering of electromagnetic particles in the heavy parts of the
detector, especially the electromagnetic barrel and endcap
calorimeters, when full showering is simulated by GEANT4. The ATLAS
simulation includes a fast simulation option that achieves a
significant improvement in simulation speed. In this technique,
simulated showers from low-energy particles are "frozen" and stored in
a library, that is distributed with each software release. These showers
are then imported at runtime during physics simulation. The
shower libraries are built and stored in separate "bins" in order to
follow geometrical variations in calorimeter response. Simulation in
the presence of frozen showers is then required to develop the shower
down to ~ 1 GeV, at which point the shower is terminated by
substituting a frozen shower. The procedure can now be applied in all
of the electromagnetic compartments of the ATLAS calorimetry.

In this talk discuss mostly the frozen shower algorithms and their
performance, but we also include a discussion of alternate approaches
to fast shower simulation (e.g. Parameterization) that can have been
applied in ATLAS.

Primary authors

Prof. Adele Rimoldi (University di Pavia and INFN) Dr Alexander Glazov (DESY) Dr Andrea Dell'Acqua (CERN) Dr Andrea DiSimone (CERN) Mr Anthony Waugh (University of Sydney) Dr Bart Butler (SLAC) Dr Charles Young (SLAC) Dr Elisabetta Barberio (University of Melbourne) Ms Emlyn Hughes (Columbia University) Dr James Mueller (University of Pittsburgh) Dr Joseph Boudreau (University of Pittsburgh) Dr Manuel Venancio Gallas (CERN) Dr Pierre Savard (University of Toronto) Dr Ringaile Placakyte (DESY) Mr Sing Leung Cheung (University of Toronto) Mr Vakhtang Tsulaia (University of Pittsburgh) Dr Wolfgang Ehrenfeld (DESY) Mr Zachary Marshall (Columbia University)

Presentation materials