Searches for Dark Photons at LHCb during Run 3

by Adrian Casais Vidal (Massachusetts Institute of Technology (MIT))

Monday 10 Feb 2025, 11:00 → 12:00 Europe/Zurich

BSP 626 / Zoom

A dark photon is a massive dark-sector force mediator. This dark-sector could be weakly-interacting with the regular matter, whereas the dark photon, even if, in the minimal model, not coupling directly to the Standard Model particles, could kinetically mix to the regular photon via a suppression factor.

LHCb is a spectrometer in the forward region. It was originally designed as a heavy-flavor detector although it has been shown for long now its potential as a general purpose experiment. Specifically, LHCb has been able to show its sensitivity to dark sectors in pp collisions in a complementary way with respect to, for instance, ATLAS and CMS. LHCb has conducted a search for a massive dark photon decaying to two muons in the mass range [211 MeV, 70 GeV] using the full Run 2 data delivered by the LHC. Right now, LHCb is collecting the Run 3 data with the upgraded detector and trigger system. The removal of the hardware trigger and the incorporation of a triggerless readout and a GPU based software trigger in the first selection layer, allows to implement neural metwork based electron and muon identification algorithms. This not only optimizes the sensitivity to the dimuon final state but also enables a more challenging dielectron search, below the dimuon threshold.

CasaisDPEPFL.pdf