Search for stable hadronising squarks and gluinos with the ATLAS experiment at the LHC

TL;DR

This paper reports a search for long-lived charged particles like squarks and gluinos at the LHC using the ATLAS detector, setting new mass limits and finding no deviations from the Standard Model.

Contribution

First search at the LHC for stable hadronising squarks and gluinos, establishing the most stringent mass limits to date for these particles.

Findings

No deviations from Standard Model expectations were observed.

Lower mass limits for stable sbottoms and stops are 294 and 309 GeV.

Lower mass limit for a stable gluino is between 562 and 586 GeV.

Abstract

Hitherto unobserved long-lived massive particles with electric and/or colour charge are predicted by a range of theories which extend the Standard Model. In this paper a search is performed at the ATLAS experiment for slow-moving charged particles produced in proton-proton collisions at 7 TeV centre-of-mass energy at the LHC, using a data-set corresponding to an integrated luminosity of 34 pb-1. No deviations from Standard Model expectations are found. This result is interpreted in a framework of supersymmetry models in which coloured sparticles can hadronise into long-lived bound hadronic states, termed R-hadrons, and 95% CL limits are set on the production cross-sections of squarks and gluinos. The influence of R-hadron interactions in matter was studied using a number of different models, and lower mass limits for stable sbottoms and stops are found to be 294 and 309 GeV respectively. The lower mass limit for a stable gluino lies in the range from 562 to 586 GeV depending on the model assumed. Each of these constraints is the most stringent to date.