Articulo
Measurement of the inclusive and fiducial t¯t production cross-sections in the lepton+jets channel in pp collisions at √s = 8 TeV with the ATLAS detector
Autor
Alconada Verzini, María Josefina
Alonso, Francisco
Arduh, Francisco Anuar
Dova, María Teresa
Hoya, Joaquín
Monticelli, Fernando Gabriel
Wahlberg, Hernán Pablo
The ATLAS Collaboration
Institución
Resumen
The inclusive and fiducial t¯t production crosssections are measured in the lepton+jets channel using 20.2 fb−1 of proton–proton collision data at a centre-of-mass energy of 8 TeV recorded with the ATLAS detector at the LHC. Major systematic uncertainties due to the modelling of the jet energy scale and b-tagging efficiency are constrained by separating selected events into three disjoint regions. In order to reduce systematic uncertainties in the most important background, the W+jets process is modelled using Z+jets events in a data-driven approach. The inclusive t¯t cross-section is measured with a precision of 5.7% to be σinc(t¯t) = 248.3±0.7 (stat.)±13.4 (syst.)±4.7 (lumi.) pb, assuming a top-quark mass of 172.5 GeV. The result is in agreement with the Standard Model prediction. The crosssection is also measured in a phase space close to that of the selected data. The fiducial cross-section is σfid(t¯t) = 48.8±0.1 (stat.)±2.0 (syst.)±0.9 (lumi.) pb with a precision of 4.5%. Facultad de Ciencias Exactas