Search for heavy, long-lived, charged particles with large ionisation energy loss in $pp$ collisions at $\sqrt{s} = 13~\text{TeV}$ using the ATLAS experiment and the full Run 2 dataset

The collaboration
CERN-EP-2022-029, 2022.

Abstract (data abstract)
This paper presents a search for hypothetical massive, charged, long-lived particles with the ATLAS detector at the LHC using an integrated luminosity of $139 \mathrm{fb^{-1}}$ of proton--proton collisions at $\sqrt{s}=13 \text{TeV}$. These particles are expected to move significantly slower than the speed of light and should be identifiable by their high transverse momenta and anomalously large specific ionisation losses, $dE/dx$. Trajectories reconstructed solely by the inner tracking system and a $dE/dx$ measurement in the pixel detector layers provide sensitivity to particles with lifetimes down to ${\cal O}(1) \text{ns}$ with a mass, measured using the Bethe--Bloch relation, ranging from $100 \text{GeV}$ to 3 $\text{TeV}$. Interpretations for pair-production of $R$-hadrons, charginos and staus in scenarios of supersymmetry compatible with these particles being long-lived are presented, with mass limits extending considerably beyond those from previous searches in broad ranges of lifetime.