Search for missing mass in proton-tagged dilepton events with the ATLAS detector and the AFP spectrometer

by Josh Lomas (University of Birmingham (GB))

Wednesday Jul 22, 2026, 1:30 PM → 2:30 PM Europe/London

Small Lecture Theatre (Poynting)

The ATLAS Forward Proton (AFP) spectrometer provides measurements of protons which undergo interactions in the ATLAS detector but remain intact, allowing for a unique type of search for new physics. This talk introduces AFP and presents a recently published search for a missing mass resonance in elastic double photon-exchange interactions using a combination of data from the ATLAS detector and the AFP spectrometer, which allows for the full reconstruction of the "missing mass" in each event. Upper limits are presented for three different signal models, which represent a significant increase in sensitivity over previous searches in this channel.