Parallelising the ATLAS Trigger and Analysis on the Higgs Boson

The first part of the project is to optimise, validate and commission the new ATLAS High Level Trigger software that is being re-written utilizing modern software techniques to fully exploit new computing architectures. The ATLAS High Level Trigger decides which collision events are to be recorded for analysis offline and which are to be discarded. Only 1 in a 100 events can be kept. The High Level Trigger does this by reconstructing features characteristic of, for example, electrons, muons, tau-leptons or groups of nearby particle (jets) using software algorithms that run on a farm of computers. The software has to be fast so that the farm can process 100,000 events per second, so each event must take less than one fifth of a second. At the moment, each computer processor core works on its own set of events running algorithms sequentially. The software is being upgraded to be fully multi-threaded so that algorithms can run in parallel. You will optimise and validate the software and help to commission the trigger to ensure it is ready for use online in 2021 when the LHC restarts after the current shutdown.
The other part of the project is a physics analysis of ATLAS data where the student will investigate properties of the Higgs boson in the ditau final state. The analysis focuses on boosted Higgs boson decays to search for deviations arising from additional couplings of the Higgs boson to unknown particles.