Measurements of Four-Lepton Production at the Z Resonance in pp Collisions at s√=7 and 8 TeV with

F. MONTICELLI; ATLAS COLLABORATION

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Lugar: New York; Año: 2014

0031-9007

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 mℓ+ℓ->5  GeV and 80<m4ℓ<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+μ- events, the branching fraction for the Z boson decay to 4ℓ is determined to be (3.20±0.25(stat)±0.13(syst))×10-6, consistent with the standard model prediction.