1. A search for the electric dipole moment of the τ-lepton
- Author
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H. Albrecht, T. Hamacher, R.P. Hofmann, T. Kirchhoff, R. Mankel, A. Nau, S. Nowak, D. Reßing, H. Schröder, H.D. Schulz, M. Walter, R. Wurth, C. Hast, H. Kapitza, H. Kolanoski, A. Kosche, A. Lange, A. Lindner, M. Schieber, T. Siegmund, H. Thurn, D. Töpfer, D. Wegener, C. Frankl, J. Graf, M. Schmidtler, M. Schramm, K.R. Schubert, R. Schwierz, B. Spaan, R. Waldi, K. Reim, H. Wegener, R. Eckmann, H. Kuipers, O. Mai, R. Mundt, T. Oest, R. Reiner, A. Rohde, W. Schmidt-Parzefall, J. Stiewe, S. Werner, K. Ehret, W. Hofmann, A. Hüpper, K.T. Knöpfle, J. Spengler, P. Krieger, D.B. MacFarlane, J.D. Prentice, P.R.B. Saull, K. Tzamariudaki, R.G. Van de Water, T.-S. Yoon, M. Schneider, S. Weseler, M. Bračko, G. Kernel, P. Križan, E. Križnič, G. Medin, T. Podobnik, T. Živko, V. Balagura, S. Barsuk, I. Belyaev, R. Chistov, M. Danilov, V. Eiges, L. Gershtein, Yu. Gershtein, A. Golutvin, O. Igonkina, I. Korolko, G. Kostina, D. Litvintsev, P. Pakhlov, S. Semenov, A. Snizhko, I. Tichomirov, and Yu. Zaitsev
- Subjects
Systematic error ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Argus ,010308 nuclear & particles physics ,FOS: Physical sciences ,Observable ,01 natural sciences ,High Energy Physics - Experiment ,High Energy Physics - Experiment (hep-ex) ,Dipole ,Electric dipole moment ,0103 physical sciences ,CP violation ,010306 general physics ,computer ,Storage ring ,Lepton ,computer.programming_language - Abstract
Using the ARGUS detector at the e+e- storage ring DORIS II, we have searched for the real and imaginary part of the electric dipole formfactor d_tau of the tau lepton in the production of tau pairs at q^2=100 GeV^2. This is the first direct measurement of this CP violating formfactor. We applied the method of optimised observables which takes into account all available information on the observed tau decay products. No evidence for CP violation was found, and we derive the following results: Re(d_tau)=(1.6+-.9)*10^(-16) ecm and Im(d_tau)=(-0.2+-0.8)*10^(-16) ecm, where statistical and systematic errors have been combined., 8 pages, 5 figures (10 subfigures)
- Published
- 2000