Full simulations

We use full MC simulations right now to study two topics. The combinatorial background from conversions in the detector material and the tracking efficiency fir the low pt electrons. The o2-sim executable is used in both cases to steer the generation of the MC.

Inputs for the conversion studies.

PYTHIA8 Pb-Pb events are generated with:

o2-sim -e TGeant3 -n 5000 -g pythia8hi -m A3IP TRK

for cross checks with previous studies we also use hijing with:

o2-sim -e TGeant3 -n 5000 -m A3IP TRK -g external --configKeyValues 'GeneratorExternal.fileName=./input/hijing.C'

The produced files can get large.

For more details on HIJING (https://alice.its.cern.ch/jira/browse/AOGM-246)[https://alice.its.cern.ch/jira/browse/AOGM-246]

Conversions

A simple macro ana.C is used to analise the kinematics files from the full simulation o2

A smearing based on look up tables produced with DelphesO2 is used to mimic a realistic detector response for the impact parameter and can be found here:

• For ALICE 3: https://cernbox.cern.ch/index.php/s/SEbT2rl9eg9Xinw
• For ITS 3: https://cernbox.cern.ch/index.php/s/pTI8MiUdUYbqLHN

Low pt tracking

We for now have a collection of scripts to steer the tracking. Thanks to David for sharing his code. runbatch.sh: The "master script" for running this. It needs an argument which is the job number, and it will create an output directory with name job_N (where N is the argument it received). It is like this so that you can conveniently run with stuff like GNU parallel or even some other bash script.

run_simulation.sh: The simulation script. You will want to edit this to change generator type and change the number of events being generated and things like that.

trigger_multiplicity.C is an auxiliary file for the generator. We ask that the simulation triggers on the presence of an electron. This can also be used to trigger on the event multiplicity.

run_strangenesstracking_01.C: This does the tracking itself and saves a file called treeouput.root which saves per-track properties.

config.ini and transport.C: Not used right now, should make it possible to select events with certain impact parameters. This could help to implement an easy centrality selection on the generator level.