Searching for Axionlike Particles with Ultraperipheral Heavy-Ion Collisions

We show that ultraperipheral heavy-ion collisions at the Large Hadron Collider (LHC) can be used to search for axionlike particles with mass below 100 GeV. The Z⁴ enhanced photon-photon luminosity from the ions provides a large exclusive production rate, with a signature of a resonant pair of back-to-back photons and no other activity in the detector. In addition, we present both new and updated limits from recasting multiphoton searches at LEP II and the LHC, which are more stringent than those currently in the literature for the mass range 100 MeV to 100 GeV.