https://doi.org/10.1007/BF01245797
Search for unstable heavy and excited leptons in e+e− collisions at ∝s = 170-172 GeV
15
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
13
Physikalisches Institut, Universitdt Bonn, D-53115, Bonn, Germany
23
Department of Physics, University of California, 92521, Riverside, CA, USA
4
Cavendish Laboratory, CB3 0HE, Cambridge, UK
21
Ottawa-Carleton Institute for Physics, Department of Physics, Carleton University, KIS 5136, Ottawa, Ontario, Canada
28
Centre for Research in Particle Physics, Carleton University, KlS 5136, 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
18
Fakultät für Physik, Albert Ludwigs Universität, D-79104, Freiburg, Germany
19
Physikalisches Institut, Universität Heidelberg, D-69120, Heidelberg, Germany
6
Department of Physics, Indiana University, Swain Hall West 117, 47405, Bloomington, IN, USA
22
Queen Mary and Westfield College, University of London, El 4NS, London, UK
14
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
12
Department of Physics, University of Maryland, 20742, College Park, MD, USA
11
Laboratoire de Physique Nucléaire, Université de Montréal, H3C 3J7, Montreal, Quebec, Canada
33
Department of Physics, University of Oregon, 97403, Eugene, OR, USA
16
Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, 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, 113, Tokyo, Japan
9
Kobe University, 657, Kobe, Japan
31
Brunel University, UB8 3PH, Uxbridge, Middlesex, UK
29
Particle Physics Department, Weizmann Institute of Science, 76100, Rehovot, Israel
17
II Institut für Experimental Physik, Universität Hamburg/DESY, Notkestrasse 85, D-22607, Hamburg, Germany
32
Department of Physics, University of Victoria, P O Box 3055, V8W 3P6, Victoria, BC, Canada
10
Department of Physics, University of British Columbia, V6T 1Z1, Vancouver, BC, Canada
26
Department of Physics, University of Alberta, T6G 2J1, Edmonton, AB, Canada
34
Dept of Physics, Duke University, 27708-0305, Durham, NC, USA
30
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
20
Sektion Physik, Ludwigs-Maximilians-Universität München, Am Coulombwall 1, D-85748, Garching, Germany
Received:
9
September
1997
Published online:
27
February
2005
We have searched for unstable neutral and charged heavy leptons, N and L±, and for excited states of neutral and charged leptons, ν* e*, μ* and τ*, in e+e− collisions at centre-of-mass energies of 170 and 172 GeV using the OPAL detector at LEP. No evidence for their existence was found. From the analysis of charged-current decays of pair-produced unstable heavy leptons, and of charged-current and photonic decays of pair-produced excited leptons, lower limits on their masses are derived. From the analysis of charged-current and photonic decays of singly-produced excited leptons, upper limits on the ratio of the coupling to the compositeness scale, ϕ/λ, are determined for masses up to the kinematic limit.
© Springer-Verlag, 1998
