Look at the dark side: dark sector and jet physics with the ATLAS experiment

Name: Look at the dark side: dark sector and jet physics with the ATLAS experiment
Start: 2021-08-24T11:00:00+02:00
End: 2021-08-24T12:00:00+02:00
Location: No location set

by Jannik Geisen

Tuesday 24 Aug 2021, 11:00 → 12:00 Europe/Stockholm

Description

The Large Hadron Collider (LHC) at CERN, Switzerland reached the conclusion of its second data taking period from 2015 to 2018, and with that produced the largest proton-proton collision particle physics dataset to date. These data are being analysed by the ATLAS experiment with ever increasing precision and even more sophisticated strategies. In particular, discovering the nature of Dark Matter in high energy proton-proton collisions is one of the experiment’s major goals.

I will present a new approach to search for Dark Matter in the full Run-2 dataset with the ATLAS experiment. Similar to the Standard Model (SM), a Dark Sector could exist in the Universe, containing new particles as well as new interactions such as a dark version of Quantum Chromodynamics (QCD). Dark QCD includes dark quarks which could be produced at the LHC. These dark quarks undergo a dark showering and hadronisation process inside the ATLAS detector producing a large number of dark and/or SM hadrons bundled together into jets. The searches that I will present exploit the internal structure of such dark jets. Furthermore, since the dark sector could be manifested in different ways resulting in different detector signatures, I will highlight the phenomenological studies which depict these features and offer optimisation strategies.

As interactions between the dark sector and the SM are rare, the expected amount of signal data at the LHC is small, buried under a large SM background. To overcome this challenge, an alternative strategy is to study a much larger amount of collision data recorded by ATLAS using only information about the data during the selection for recording to storage. This offers a significantly increased statistical power over traditional techniques. I will illustrate how to employ such a Trigger-Level-Analysis on detector signatures involving jets with the ATLAS experiment to help in the search for Dark Matter.

To ensure these reconstructed jets are of the highest quality, new advances in data quality monitoring of jets will be shown for the Run-2 architecture as well as on-going preparations towards Run-3 which is scheduled to start in 2022.