Measurements of four-lepton (4, =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+->5GeV and 80<m4<100GeV, 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 4 production contributions and normalizing with Z→μ+μ- events, the branching fraction for the Z boson decay to 4 is determined to be (3.20±0.25(stat)±0.13(syst))×10-6, consistent with the standard model prediction.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)