The inclusive production of four isolated charged leptons in pp collisions is analysed for the presence of hard double-parton scattering, using 20.2 fb^-1 of data recorded in the ATLAS detector at the LHC at centre-of-mass energy sqrt(s) = 8 TeV. In the four-lepton invariant-mass range of 80<100 GeV, an artificial neural network is used to enhance the separation between single- and double-parton scattering based on the kinematics of the four leptons in the final state. An upper limit on the fraction of events originating from double-parton scattering is determined at 95% confidence level to be fDPS=0.042, which results in an estimated lower limit on the effective cross section at 95% confidence level of 1.0 mb.
Study of the hard double-parton scattering contribution to inclusive four-lepton production in pp collisions at sqrt(s) = 8 TeV with the ATLAS detector
G Chiodini;E Gorini;L Longo;A Mirto;M Reale;E Schioppa;S Spagnolo;A Ventura;and ATLAS Collaboration
2019-01-01
Abstract
The inclusive production of four isolated charged leptons in pp collisions is analysed for the presence of hard double-parton scattering, using 20.2 fb^-1 of data recorded in the ATLAS detector at the LHC at centre-of-mass energy sqrt(s) = 8 TeV. In the four-lepton invariant-mass range of 80<100 GeV, an artificial neural network is used to enhance the separation between single- and double-parton scattering based on the kinematics of the four leptons in the final state. An upper limit on the fraction of events originating from double-parton scattering is determined at 95% confidence level to be fDPS=0.042, which results in an estimated lower limit on the effective cross section at 95% confidence level of 1.0 mb.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.