  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 $\sqrt{s}$ = 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 $\ell\ell
q q$ contact interaction scale $\Lambda$ 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.
