The main fraction of the 24 month of this project was spent on developing the analysis of proton-proton collisions recorded with the ATLAS detector that contain the signature of two hadronically decaying tau leptons and so called missing transverse energy. The latter is a measure of the imbalance of transverse momentum in the detector and a typical signature of a Dark Matter (DM) particle escaping detection. The two tau leptons arise from the decay of the Higgs boson that is assumed to be produced in addition to the DM. In a first step, the latest models describing DM production in hadron collisions were reviewed in the beginning of the project. Two models were chosen as reference points for the analysis. The signature of these models was then simulated using Monte Carlo methods. This signal simulation was employed to develop the analysis strategy. The latter includes the best way to select the signal such that a region with high signal purity is reached. In addition, the best way to trigger the readout of the signal events has been studied. Different ways to estimate the background from Standard Model processes have been explored and the best ones chosen for the final analysis. Furthermore, it was studied which variables yield the best sensitivity for the signal and the statistical interpretation of the data was implemented.
This work was fully integrated in the ATLAS Collaboration with regular reports at internal meetings and a detailed supporting document written for internal use. In addition, contributions to the efforts of the collaboration to statistically combine several DM searches were made in order to exploit this analysis best.
Apart from the scientific work, I invested time in my personal development and the management of this fellowship. I took on coordinating tasks, attended conferences and supervised students. Furthermore, I initialised a network for female researchers at the subatomic group of my host institute. I organised 2 outreach events for high school students and wrote an article for the homepage of our research group. I was also the invited speaker of an event to encourage more researchers at my host institution to apply for external funding.
