Search for metastable heavy charged particles with large ionisation energy loss in $pp$ collisions at $\sqrt{s}$ = 8 TeV using the ATLAS experiment

Understand

Many extensions of the Standard Model predict the existence of charged heavy long-lived particles, such as $R$-hadrons or charginos.

• These particles, if produced at the Large Hadron Collider, should be moving non-relativistically and are therefore identifiable through the measurement of an anomalously large specific energy loss in the ATLAS pixel detector.
• Measuring heavy long-lived particles through their track parameters in the vicinity of the interaction vertex provides sensitivity to metastable particles with lifetimes from 0.6 ns to 30 ns.
• A search for such particles with the ATLAS detector at the Large Hadron Collider is presented, based on a data sample corresponding to an integrated luminosity of 18.4 fb$^{-1}$ of $pp$ collisions at $\sqrt{s}$ = 8 TeV.