Search for heavy long-lived multi-charged particles in the full LHC Run 2 Collision Data at TeV using the ATLAS detector

A search for heavy long-lived multi-charged particles is performed using the ATLAS detector at the LHC. Data collected in 2015–2018 at $\sqrt{s}=13$ TeV from pp collisions corresponding to an integrated luminosity of 139 fb$^{−1}$ are examined. Particles producing anomalously high ionization, consistent with long-lived spin-½ massive particles with electric charges from $|q|=2e$ to $|q|=7e$ are searched for. No statistically significant evidence of such particles is observed, and 95% confidence level cross-section upper limits are calculated and interpreted as the lower mass limits for a Drell–Yan plus photon-fusion production mode. The least stringent limit, 1060 GeV, is obtained for $|q|=2e$ particles, and the most stringent one, 1600 GeV, is for $|q|=6e$ particles.