Prof. Dr. Michael Klasen
Westfälische Wilhelms-Universität, Münster
T a l k: 11. May 2023
Dark photon constraints and discovery prospects at the LHC and FPF
Hidden sectors are ubiquitous in supergravity theories, in strings and in branes. Well motivated models such as the Stueckelberg hidden sector model could provide a candidate for dark matter. In such models, the hidden sector communicates with the visible sector via the exchange of a dark photon (or Z' boson), while dark matter is constituted of Dirac fermions in the hidden sector. Using data from collider searches and precision measurements of SM processes as well as the most recent limits from dark matter direct and indirect detection experiments, we perform a comprehensive scan over a wide range of the dark photon mass and set exclusion bounds on the parameter space from sub-GeV to several TeV. We then discuss the discovery potential of an O(TeV) scale Z' boson at the HL-LHC and the ability of future forward detectors to probe very weakly interacting sub-GeV dark photons. Our analysis shows that the parameter space in which a Z' boson can decay to hidden sector dark matter is severely constrained, whereas limits become much weaker for a Z' with no dark decays. The analysis also favors a self-thermalized dark sector, which is necessary to satisfy the dark matter relic density.