PHYSICS AT THE HL-LHC WITH PROTON TAGGING^∗

The High-Luminosity Large Hadron Collider (HL-LHC), a major upgrade of the LHC, is set to operate in 2029. The HL-LHC aims to achieve higher instantaneous luminosities to allow exploration of the rarest production processes of the Standard Model (SM). The central exclusive production (CEP) process in proton–proton collisions at the HL-LHC can only be explored using a forward proton spectrometer (FPS), a set of near-beam detectors located a few hundred meters from the proton–proton interaction point. During LHC Run 2, the ATLAS and CMS collaborations installed FPSs delivering a broad range of physics results. The accelerator complex will be rearranged for the HL-LHC, and a new FPS detector design is under development. The CEP study offers a unique opportunity to observe the rarest SM processes and search for physics beyond the SM, including axion-like particles or anomalous gauge couplings.