Search for Magnetic Monopole Pair Production in Ultraperipheral Pb + Pb Collisions at √sNN=5.36 TeV with the ATLAS Detector at the LHC

Abstract

This Letter presents a search for highly ionizing magnetic monopoles in 262 μb-1 of ultraperipheralPb + Pb collision data atSQUARE ROOTsNN = 5.36 TeV collected by the ATLAS detector at the LHC. A newmethodology that exploits the properties of clusters of hits reconstructed in the innermost silicon detectorlayers is introduced to study highly ionizing particles in heavy-ion data. No significant excess above thebackground, which is estimated using a data-driven technique, is observed. Using a nonperturbativesemiclassical model, upper limits at 95% confidence level are set on the cross section for pair production ofmonopoles with a single Dirac magnetic charge in the mass range of 20-150 GeV. Depending on the model, monopoles with a single Dirac magnetic charge and mass below 80-120 GeV are excluded.