PT Journal AU ATLAS Collaboration (Aaboud, Mea Alvarez Piqueras, D Barranco Navarro, L Cabrera Urban, S Castillo Gimenez, V Cerda Alberich, L Costa, MJ Estrada Pastor, O Fernandez Martinez, P Ferrer, A Fiorini, L Fuster, J Garcia, C Garcia Navarro, JE Gonzalez de la Hoz, S Higon-Rodriguez, E Jimenez Pena, J Lacasta, C Madaffari, D Mamuzic, J Marti-Garcia, S Melini, D Mitsou, VA Pedraza Lopez, S Rodriguez Bosca, S Rodriguez Rodriguez, D Romero Adam, E Salt, J Sanchez Martinez, V Soldevila, U Sanchez, J Valero, A Valls Ferrer, JA Vos, M TI Search for new phenomena in a lepton plus high jet multiplicity final state the ATLAS experiment using root S=13 TeV proton-proton collision data SO Journal of High Energy Physics JI J. High Energy Phys. PY 2017 BP 088 EP 50pp VL 09 IS 9 DI 10.1007/JHEP09(2017)088 LA English DE Beyond Standard Model; Hadron-Hadron scattering (experiments) AB A search for new phenomena in final states characterized by high jet multiplicity, an isolated lepton ( electron or muon) and either zero or at least three b-tagged jets is presented. The search uses 36.1 fb(-1) of root s = 13TeV proton-proton collision data collected by the ATLAS experiment at the Large Hadron Collider in 2015 and 2016. The dominant sources of background are estimated using parameterized extrapolations, based on observables at medium jet multiplicity, to predict the b-tagged jet multiplicity distribution at the higher jet multiplicities used in the search. No significant excess over the Standard Model expectation is observed and 95% confidence-level limits are extracted constraining four simplified models of R-parity-violating supersymmetry that feature either gluino or top-squark pair production. The exclusion limits reach as high as 2.1TeV in gluino mass and 1.2TeV in top-squark mass in the models considered. In addition, an upper limit is set on the cross-section for Standard Model t (t) over bart (t) over bar production of 60 fb (6.5 x the Standard Model prediction) at 95% confidence level. Finally, model-independent limits are set on the contribution from new phenomena to the signal-region yields. ER