Measurements of four-lepton production at the Z resonance in pp collisions at √s = 7 and 8 TeV with ATLAS

Measurements of four-lepton (4ℓ, ℓ =e,μ) production cross sections at the Z resonance in pp collisions at the LHC with the ATLAS detector are presented. For dilepton and four-lepton invariant mass regions m<SUB>ℓ+ℓ-</SUB> > 5 GeV and 80 < m<SUB>4ℓ</SUB> < 100 GeV, th...

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Autores principales: Alconada Verzini, María Josefina, Alonso, Francisco, Anduaga, Xabier Sebastián, Dova, María Teresa, Monticelli, Fernando Gabriel, Tripiana, Martín Fernando, The ATLAS Collaboration
Formato: Articulo
Lenguaje:Inglés
Publicado: 2014
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Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/85175
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Sumario:Measurements of four-lepton (4ℓ, ℓ =e,μ) production cross sections at the Z resonance in pp collisions at the LHC with the ATLAS detector are presented. For dilepton and four-lepton invariant mass regions m<SUB>ℓ+ℓ-</SUB> > 5 GeV and 80 < m<SUB>4ℓ</SUB> < 100 GeV, the measured cross sections are 76 ± 18 (stat) ± 4 (syst) ± 1.4 (lumi) fb and 107 ± 9 (stat )± 4 (syst) ± 3.0 (lumi) fb at √s = 7 and 8 TeV, respectively. By subtracting the nonresonant 4ℓ production contributions and normalizing with Z→ μ<SUP>+</SUP>μ<SUP>-</SUP> events, the branching fraction for the Z boson decay to 4ℓ is determined to be (3.20 ± 0.25 (stat) ± 0.13 (syst)) × 10<SUP>-6</SUP>, consistent with the standard model prediction.