Inclusive Dark Photon Search at LHCb

TL;DR

This paper proposes a novel, data-driven inclusive search for dark photons at LHCb, exploiting prompt and displaced di-muon resonances to explore new parameter space with high precision.

Contribution

It introduces an innovative inclusive search strategy for dark photons at LHCb, utilizing off-shell photon rates for a fully data-driven approach and targeting unexplored mass regions.

Findings

Sensitivity to large regions of dark-photon parameter space

Effective use of LHCb's invariant-mass and vertex resolution

Potential to explore 210-520 MeV and 10-40 GeV mass ranges

Abstract

We propose an inclusive search for dark photons $A'$ at the LHCb experiment based on both prompt and displaced di-muon resonances. Because the couplings of the dark photon are inherited from the photon via kinetic mixing, the dark photon $A' \to \mu^+ \mu^-$ rate can be directly inferred from the off-shell photon $\gamma^* \to \mu^+ \mu^-$ rate, making this a fully data-driven search. For Run 3 of the LHC, we estimate that LHCb will have sensitivity to large regions of the unexplored dark-photon parameter space, especially in the 210-520 MeV and 10-40 GeV mass ranges. This search leverages the excellent invariant-mass and vertex resolution of LHCb, along with its unique particle-identification and real-time data-analysis capabilities.