Study of Vertex Reconstructions with Di-Photon Events and First Determination of Time Resolution and Efficiency of the Time-of-Fight (ToF) Detector with LHC Run-3 Data

In summer 2022, first LHC Run-3 pp collision data were recorded with the ATLAS central detector and the ATLAS Forward Proton (AFP) detectors at the Large Hadron Collider. A first analysis of this new data was performed. Efficiencies and resolutions for the Time-of-Flight (ToF) detector were studied with different meth- ods. In addition, we conducted vertex reconstruction studies in this project. They were performed based on data taken in 2017. Different techniques of vertex recon- struction were compared, and the most appropriate one for future di-photon studies was determined. The potential of ToF data for an improved vertex reconstruction and thus reduction of background in an Axion-Like-Particle search using AFP data was demonstrated.