https://doi.org/10.1007/BF01245795
Multi-photon final states in e+e− collisions at ∝s =130-172 GeV
14
School of Physics and Space Research, University of Birmingham, B15 2TT, Birmingham, UK
7
Dipartimento di Fisica dell' Università di Bologna and INFN, I-40126, Bologna, Italy
12
Physikalisches Institut, Universität Bonn, D-53115, Bonn, Germany
23
Department of Physics, University of California, 92521, Riverside, CA, USA
4
Cavendish Laboratory, CB3 0HE, Cambridge, UK
20
Ottawa-Carleton Institute for Physics, Department of Physics, Carleton University, K1S 5B6, Ottawa, Ontario, Canada
29
Centre for Research in Particle Physics, Carleton University, K1S 5B6, Ottawa, Ontario, Canada
1
CERN, European Organisation for Particle Physics, CH-1211, Geneva 23, Switzerland
5
Enrico Fermi Institute and Department of Physics, University of Chicago, 60637, Chicago, IL, USA
17
Fakultät für Physik, Albert Ludwigs Universität, D-79104, Freiburg, Germany
18
Physikalisches Institut, Universität Heidelberg, D-69120, Heidelberg, Germany
6
Department of Physics, Indiana University, Swain Hall West 117, 47405, Bloomington, IN, USA
21
Queen Mary and Westfield College, University of London, E1 4NS, London, UK
13
III Physikalisches Institut, Technische Hochschule Aachen, Sommerfeldstrasse 26-28, D-52056, Aachen, Germany
24
University College London, WC1E 6BT, London, UK
3
Department of Physics, Schuster Laboratory, The University, M13 9PL, Manchester, UK
11
Department of Physics, University of Maryland, 20742, College Park, MD, USA
9
Laboratoire de Physique Nucléaire, Université de Montréal, H3C 3J7, Montréal, Quebec, Canada
36
Department of Physics, University of Oregon, 97403, Eugene, OR, USA
15
Rutherford Appleton Laboratory, OX11 0QX, Chilton, Didcot, Oxfordshire, UK
25
Department of Physics, Technion-Israel Institute of Technology, 32000, Haifa, Israel
2
Department of Physics and Astronomy, Tel Aviv University, 69978, Tel Aviv, Israel
8
International Centre for Elementary Particle Physics and Department of Physics, University of Tokyo, Tokyo, 113, Japan
32
Brunel University, U138 3PH, Uxbridge, Middlesex, UK
30
Particle Physics Department, Weizmann Institute of Science, 76100, Rehovot, Israel
16
II Institut für Experimental Physik, Universität Hamburg/DESY, Notkestrasse 85, D-22607, Hamburg, Germany
33
Department of Physics, University of Victoria, P O Box 3055, V8W 3P6, Victoria, BC, Canada
35
Department of Physics, University of British Columbia, V6T 1Z1, Vancouver, BC, Canada
26
Department of Physics, University of Alberta, T6G 2J1, Edmonton, AB, Canada
37
Dept of Physics, Duke University, 27708-0305, Durham, NC, USA
31
Research Institute for Particle and Nuclear Physics, P O Box 49, H-1525, Budapest, Hungary
27
Institute of Nuclear Research, P O Box 51, H-4001, Debrecen, Hungary
19
Sektion Physik, Ludwigs-Maximilians-Universitat München, Am Coulombwall 1, D-85748, Garching, Germany
10
TRIUMF, V6T 2A3, Vancouver, Canada
22
Royal Society University Research Fellow, Canada
34
Institute of Nuclear Research, Debrecen, Hungary
28
Department of Experimental Physics, Lajos Kossuth University, Debrecen, Hungary
38
Department of Physics, New York University, 1003, NY, USA
Received:
11
August
1997
Published online:
27
February
2005
The process e+e− →, γγ(γ) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 25.38 pb−1 taken at centre-of-mass energies of 130–172 GeV. The measured cross-sections agree well with the expectation from QED. In a combined fit using data from all centre-of-mass energies, the angular distribution is used to obtain improved limits on the cut-off parameters: Λ+ > 195 GeV and Λ− > 210 GeV (95% CL). In addition, limits on nonstandard e+e−γ couplings and contact interactions, as well as a 95% CL mass limit for an excited electron,Me*= > 194 GeV for an e+e−γ coupling κ = 1, are determined.
© Springer-Verlag, 1998