Search for Quantum Black Holes in Lepton+Jet Final State Using pp-Collisions at $\sqrt{s}$ = 8 TeV with the ATLAS

Search for quantum black holes (QBHs) was performed with proton-proton collision data collected by the ATLAS detector at the LHC in 2012 at a center-of-mass energy $\sqrt{s}$ = 8 TeV with the integrated luminosity of 20.3 fb$^{-1}$. The QBH production is modeled with the ADD-model with the number of large extra dimensions $n$ = 6. The QBH is assumed to decay into a final state with a lepton (electron or muon) and a jet. This final state is preferred in the above model and it is assumed to be sensitive to the TeV scale gravity. There are no events with a lepton-jet invariant mass of 3.5 TeV or more in both electron and muon channel. The measurement is consistent with the expected background. The combined 95\% confidence level upper limit on product of the QBH production cross sections and the branching fractions of decay into the lepton+jet is equal to 0.18 fb. The upper limit constrains the threshold quantum black-hole mass to be above 5.3 TeV in the model considered.