This book addresses one of the most intriguing mysteries of our universe: the nature of dark matter. The results presented here mark a significant and substantial contribution to the search for new physics, in particular for new particles that couple to dark matter. The first analysis presented is a search for heavy new particles that decay into pairs of hadronic jets (dijets). This pioneering analysis explores unprecedented dijet invariant masses, reaching nearly 7 TeV, and sets constraints on several important new physics models. The two subsequent analyses focus on the difficult low dijet mass region, down to 200 GeV, and employ a novel technique to efficiently gather low-mass dijet events. The results of these analyses transcend the long-standing constraints on dark matter mediator particles set by several existing experiments.

Autorentext

The author became a member of the ATLAS collaboration in 2012 when she was a Master's student in Physics at the University of Manchester. During her Master's degree she worked on measuring the high-mass Drell-Yan differential cross-section in the muon decay channel. She then obtained her DPhil in Particle Physics from the University of Oxford, where her research was focused on the search for exotic new particles in jet final states. Since October 2017 she has been a Junior Research Fellow at St. John's College, University of Oxford.

Inhalt
Theoretical Background.- The ATLAS Experiment.- Physics Object Reconstruction in ATLAS.- Dijet Invariant Mass Spectra.- Searching for Resonances.- Limit Setting.- Conclusion and Outlook.