Abstract
The total cross section and the forward-backward asymmetry for the process e+e- → μ+μ- (nγ) are measured in the energy range 20-136 GeV by reconstructing the effective centre-of-mass energy after initial state radiation. The analysis is based on the data recorded with the ALEPH detector at LEP between 1990 and 1995, corresponding to a total integrated luminosity of 143.5 pb-1. Two different approaches are used: in the first one an exclusive selection of events with hard initial state radiation in the energy range 20-88 GeV is directly compared with the Standard Model predictions showing good agreement. In the second one, all events are used to obtain a precise measurement of the energy dependence of σ0 and A0FB from a model independent fit, enabling constraints to be placed on models with extra Z bosons.
Original language | English (US) |
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Pages (from-to) | 329-341 |
Number of pages | 13 |
Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
Volume | 399 |
Issue number | 3-4 |
DOIs | |
State | Published - May 1 1997 |
Funding
Forschung und Technologie, Germany. l7 Supported by the Direction des Sciences de la Mat&e, C.E.A. ls Supported by Fonds zur Fiirdemng der wissenschaftlichen Forschung, Austria. lg Permanent address: Kangnung National University, Kangnung, Korea. zo Also at Istituto di Matematica e Fisica, Universita di Sassari, Sassari, Italy. ” Also at CERN, 1211 Geneva 23, Switzerland. 22 Supported by the US Department of Energy, grant DE-FGOS-92ER40689. 23 Now at Harvard University, Cambridge, MA 02138, USA. 2p,N ow at Max-Plank-Instittit fiir Kcmphysik, Heidelberg, Germany. 25 Now at Dragon Systems, Newton, MA 02160, USA. 1 Now at DESY, Hamburg, Germany. 2 Supported by Direccidn General de Investigacibn Cientifica y T&nica, Spain. 3 Also at Dipartimento di Fisica, INFN Sezione di Catania, Cata-nia, Italy. 4 Also Istituto di Fisica Generale, Universiti di Torino, Torino, Italy. 5 Also Istituto di Cosmo-Geofisica de1 C.N.R., Torino, Italy. 6 Supported by the Commission of the European Communities, contract ERBCHBICT941234. 7 Supported by CICYT, Spain. * Supported by the National Science Foundation of China. 9 Supported by the Danish Natural Science Research Council. lo Supported by the UK Particle Physics and Astronomy Research Council. l1 Supported by the US Department of Energy, grant DE-FG0295-ER40896. l2 Now at The Johns Hopkins University, Baltimore, MD 21218, USA. l3 Supported by the US Department of Energy, contract DE-FGOS-92ER40742. l4 Supported by the US Department of Energy, contract DE-FCOS-85ER250000. l5 Permanent address: Universitat de Barcelona, 08208 Barcelona, Spain. l6 Supported by the Bundesministerium fdr Bildung, Wissenschaft,
ASJC Scopus subject areas
- Nuclear and High Energy Physics