Searches for heavy long-lived charged particles with the ATLAS detector in proton-proton collisions at $\sqrt{s}$ = 8 TeV

TL;DR

This paper reports on searches for heavy long-lived charged particles in proton-proton collisions at 8 TeV using the ATLAS detector, setting new limits on their masses across various supersymmetric models with no observed excess.

Contribution

First comprehensive search for heavy long-lived charged particles at 8 TeV with ATLAS, providing new mass exclusion limits in multiple supersymmetric scenarios.

Findings

Excluded long-lived tau slepton masses up to 440 GeV.

Excluded squark and gluino masses up to 1500 GeV and 1360 GeV.

Excluded charginos up to 620 GeV.

Abstract

Searches for heavy long-lived charged particles are performed using a data sample of 19.8 fb$^{-1}$ from proton-proton collisions at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV collected by the ATLAS detector at the Large Hadron Collider. No excess is observed above the estimated background and limits are placed on the mass of long-lived particles in various supersymmetric models. Long-lived tau sleptons in models with gauge-mediated symmetry breaking are excluded up to masses between 440 and 385 GeV for $\tan\beta$ between 10 and 50, with a 290 GeV limit in the case where only direct tau slepton production is considered. In the context of simplified LeptoSUSY models, where sleptons are stable and have a mass of 300 GeV, squark and gluino masses are excluded up to a mass of 1500 and 1360 GeV, respectively. Directly produced charginos, in simplified models where they are nearly degenerate to the lightest neutralino, are excluded up to a mass of 620 GeV. $R$-hadrons, composites containing a gluino, bottom squark or top squark, are excluded up to a mass of 1270, 845 and 900 GeV, respectively, using the full detector; and up to a mass of 1260, 835 and 870 GeV using an approach disregarding information from the muon spectrometer.