Four-fermion production in e+e- collisions at centre-of-mass energies of 130 and 136 GeV

European Organization for Nuclear Research
Sezione di Milano Istituto Nazionale di Fisica Nucleare
Sezione di Bari Istituto Nazionale di Fisica Nucleare
Service de Physique des Particules
Santa Cruz Institute for Particle Physics
Laboratoire de l'Accélérateur Linéaire
University of Wisconsin Madison
Johannes Gutenberg Universität Mainz
Deutsche Elektronen-Synchrotron
The State University of New Jersey Rutgers
Università di Pisa
Institute of High Energy Physics Chinese Academy of Science
Universita del Salento
IN2P3 Institut National de Physique Nucleaire et de Physique des Particules
Lancaster University
Universität Siegen
Universitat Autònoma de Barcelona
Rutherford Appleton Laboratory
Consiglio Nazionale delle Ricerche
Università degli Studi di Firenze

Abstract

Four-fermion events have been selected in a data sample of 5.8 pb−1 collected with the aleph detector at centre-of-mass energies of 130 and 136 GeV. The final states ℓ+ℓ−qq, ℓ+ℓ−ℓ+ℓ−, ννqq, and ννℓ+ℓ− have been examined. Five events are observed in the data, in agreement with the Standard Model predictions of 6.67±0.38 events from four-fermion processes and 0.14−0.05+0.19 from background processes.