Study of the four fermion final state at the Z resonance

UNSPECIFIED (1995) Study of the four fermion final state at the Z resonance. Zeitschrift für Physik C Particles and Fields, 66 (1-2). pp. 3-18. ISSN 0170-9739

Abstract

The process e+e−→, where l is a charged or a neutral lepton and f any charged fermion, is analyzed. The study uses the ALEPH data collected at LEP from 1989 to 1993 at centre-of-mass energies between 88 and 95 GeV, corresponding to almost two million hadronic Z decays and to a total integrated luminosity of 79 pb−1. For all channels, the data agree well with the standard model expectation both in shape and normalization. The indication of an excess in the e+e−→τ+τ−ffˉ channel, reported by ALEPH in 1991, is not confirmed.