The European Physical Journal C > 2015 > 75 > 9 > 1-25
Search for metastable heavy charged particles with large ionisation energy loss in pp collisions at $$\varvec{\sqrt{s} = 8}$$ s = 8 TeV using the ATLAS experiment
Source
Abstract
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 $$18.4$$ 18.4 fb $$^{-1}$$ - 1 of pp collisions at $$\sqrt{s} = 8$$ s = 8 TeV. No significant deviation from the Standard Model background expectation is observed, and lifetime-dependent upper limits on R-hadrons and chargino production are set. Gluino R-hadrons with 10 ns lifetime and masses up to 1185 GeV are excluded at 95 $$\%$$ % confidence level, and so are charginos with 15 ns lifetime and masses up to 482 GeV.
Identifiers
journal ISSN : | 1434-6044 |
journal e-ISSN : | 1434-6052 |
DOI | 10.1140/epjc/s10052-015-3609-0 |