Measurement of the inclusive t¯t production cross section in the lepton + jets channel in pp collisions at ffiffi ps = 7 TeV with the ATLAS detector using support vector machines

Abstract

A measurement of the top quark pair-production cross section in the lepton þ jets decay channel is presented. It is based on 4.6 fb−1 of ffiffiffisp ¼ 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 ¼ 168.5 0.7ðstatÞ þ6.2 −5.9 ðsystÞ þ3.4 −3.2 ðlumiÞ pb. The result is consistent with the Standard Model prediction based on QCD calculations at next-to-next-to-leading ord