A measurement of the production cross-section for top quark pairs (tt ??) in pp collisions at ???s = 7 TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two dif- ferent topologies: single lepton (electron e or muon ??) with large missing transverse energy and at least four jets, and dilepton (ee, ???? or e??) with large missing transverse en- ???1 ergy and at least two jets. In a data sample of 2.9 pb , 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding ex- pected backgrounds from non-tt ?? Standard Model processes are estimated using data-driven methods and determined to be 12.2 ± 3.9 events and 2.5 ± 0.6 events, respectively. The kinematic properties of the selected events are consistent with SM tt ?? production. The inclusive top quark pair pro- duction cross-section is measured to be +42 ??tt ?? = 145 ± 31(stat.)???27(syst.) pb. The measurement agrees with perturbative QCD calcula- tions.
Measurement of the top quark-pair production cross section with ATLAS in pp collisions at $\sqrt{s}=7$ TeV / Aad, G., Aloisio, A., Alviggi, M., Canale, V., Cevenini, F., Chiefari, G., DELLA VOLPE, D., Merola, L., Patricelli, S., Conventi, F., DELLA PIETRA, M., Giordano, R., Musto, E., Rossi, E., Sanchez, A., Carlino, G., de Asmundis, R., Doria, A., Izzo, V., Sekhniaidze, G.. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - 71:(2011), pp. 1577-1612. [10.1140/epjc/s10052-011-1577-6]
Measurement of the top quark-pair production cross section with ATLAS in pp collisions at $\sqrt{s}=7$ TeV
ALOISIO, ALBERTO;ALVIGGI, MARIAGRAZIA;CANALE, VINCENZO;CEVENINI, FRANCESCO;CHIEFARI, GIOVANNI;DELLA VOLPE, DOMENICO;MEROLA, LEONARDO;PATRICELLI, SERGIO;DELLA PIETRA, MASSIMO;GIORDANO, RAFFAELE;Rossi E.;
2011
Abstract
A measurement of the production cross-section for top quark pairs (tt ??) in pp collisions at ???s = 7 TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two dif- ferent topologies: single lepton (electron e or muon ??) with large missing transverse energy and at least four jets, and dilepton (ee, ???? or e??) with large missing transverse en- ???1 ergy and at least two jets. In a data sample of 2.9 pb , 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding ex- pected backgrounds from non-tt ?? Standard Model processes are estimated using data-driven methods and determined to be 12.2 ± 3.9 events and 2.5 ± 0.6 events, respectively. The kinematic properties of the selected events are consistent with SM tt ?? production. The inclusive top quark pair pro- duction cross-section is measured to be +42 ??tt ?? = 145 ± 31(stat.)???27(syst.) pb. The measurement agrees with perturbative QCD calcula- tions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
