  A search for an excess of events with multiple high transverse momentum
objects including charged leptons and jets is presented, using 20.3 fb^-1 of
proton-proton collision data recorded by the ATLAS detector at the Large Hadron
Collider in 2012 at a centre-of-mass energy of sqrt(s) = 8 TeV. No excess of
events beyond Standard Model expectations is observed. Using extra-dimensional
models for black hole and string ball production and decay, exclusion contours
are determined as a function of the mass threshold for production and the
fundamental gravity scale for two, four and six extra dimensions. For six extra
dimensions, mass thresholds of 4.8-6.2 TeV are excluded at 95% confidence
level, depending on the fundamental gravity scale and model assumptions. Upper
limits on the fiducial cross-sections for non-Standard Model production of
these final states are set.
