Measurement of the inclusive tt¯ production cross section in the lepton+jets channel in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector using support vector machines

A measurement of the top quark pair-production cross section in the lepton+jets decay channel is presented. It is based on 4.6 fb−1 of sqrt(s) = 7 TeV pp collision data collected during 2011 by the ATLAS experiment at the CERN Large Hadron Collider. A three-class, multidimensional event classifier based on support vector machines is used to differentiate t¯t events from backgrounds. The t¯t production cross section is found to be σt¯t= 168.5±0.7(stat)+6.2−5.9(syst)+3.4−3.2(lumi) pb. The result is consistent with the Standard Model prediction based on QCD calculations at next-to-next-to-leading order.