Search for Contact Interactions and Large Extra Dimensions in the Dilepton Channel Using Proton−Proton Collisions at √s = 8 TeV with the ATLAS Detector


A search is conducted for non-resonant new phenomena in dielectron and dimuon final states, originating from either contact interactions or large extra spatial dimensions. The LHC 2012 proton−proton collision dataset recorded by the ATLAS detector is used, corresponding to 20 fb⁻¹ at √s = 8 TeV. The dilepton invariant mass spectrum is a discriminating variable in both searches, with the contact interaction search additionally utilizing the dilepton forward-backward asymmetry. No significant deviations from the Standard Model expectation are observed. Lower limits are set on the ℓℓqq contact interaction scale Λ between 15.4 TeV and 26.3 TeV, at the 95% credibility level. For large extra spatial dimensions, lower limits are set on the string scale M(s) between 3.2 TeV to 5.0 TeV.



Leptons (Nuclear physics), Muons, Mass (Physics), Proton-proton interactions, Standard model (Nuclear physics)


CC BY 4.0 (Attribution), ©2014 CERN, for the ATLAS Collaboration