https://doi.org/10.1007/BF01245798
Three-prong τ decays with charged kaons
1
Laboratoire de Physique des Particules (LAPP), INP-CNRS, F-74019, Annecy-le-Vieux Cedex, France
2
Institut de Física d'Altes Energies, Universitat Autònoma de Barcelona, E-08193, Bellaterra (Barcelona), Spain
3
Dipartimento di Fisica, INFN Sezione di Bari, I-70126, Bari, Italy
4
Institute of High-Energy Physics, Academia Sinica, Beijing, The People's Republic of China
5
European Laboratory for Particle Physics (CERN), CH-1211, Geneva, 23, Switzerland
6
Laboratoire de Physique Corpusculaire, Université Blaise Pascal, Clermont-Ferrand, INP-CNRS, F-63177, Aubière, France
7
Niels Bohr Institute, DK-2100, Copenhagen, Denmark
8
Nuclear Research Center Demokritos (NRCD), Athens, Greece
9
Laboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, INP-CNRS, F-91128, Palaiseau Cedex, France
10
Department of Physics, University of Edinburgh, EH9 3JZ, Edinburgh, UK
11
Dipartimento di Fisica, Università di Firenze, INFN Sezione di Firenze, I-50125, Firenze, Italy
12
Supercomputer Computations Research Institute, Florida State University, FL 32306-4052, Tallahassee, USA
14
Laboratori Nazionali dell'INFN (LNF-INFN), I-00044, Frascati, Italy
15
Department of Physics and Astronomy, University of Glasgow, G12 8QQ, Glasgow, UK
16
Institut für Hochenergiephysik, Universität Heidelberg, D-69120, Heidelberg, Germany
18
Department of Physics, Imperial College, SW7 2BZ, London, UK
19
Institut für Experimentalphysik, Universität Innsbruck, A-6020, Innsbruck, Austria
20
Department of Physics, University of Lancaster, LA1 4YB, Lancaster, UK
21
Institut für Physik, Universität Mainz, D-55099, Mainz, Germany
22
Centre de Physique des Particules, Faculté des Sciences de Luminy, INP-CNRS, F-13288, Marseille, France
23
Dipartimento di Fisica, Università di Milano e INFN Sezione di Milano, I-20133, Milano, Italy
25
Max-Planck-Institut für Physik, Werner-Heisenberg-Institut, D-80805, München, Germany
26
Laboratoire de l'Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405, Orsay Cedex, France
27
Dipartimento di Fisica dell'Università, INFN Sezione di Pisa, e Scuola Normale Superiore, I-56010, Pisa, Italy
28
Department of Physics, Royal Holloway & Bedford New College, University of London, TW20 OEX, Surrey, UK
29
Particle Physics Department, Rutherford Appleton Laboratory, OX11 OQX, Chilton, Didcot, Oxon, UK
30
CEA, DAPNIA/Service de Physique des Particules, CE-Saclay, F-91191, Gif-sur-Yvette Cedex, France
31
Institute for Particle Physics, University of California at Santa Cruz, 95064, Santa Cruz, CA, USA
32
Department of Physics, University of Sheffield, S3 7RH, Sheffield, UK
33
Fachbereich Physik, Universität Siegen, D-57068, Siegen, Germany
34
Dipartimento di Fisica, Università di Trieste e INFN Sezione di Trieste, I-34127, Trieste, Italy
35
Experimental Elementary Particle Physics, University of Washington, WA 98195, Seattle, USA
36
Department of Physics, University of Wisconsin, WI 53706, Madison, USA
Received:
24
June
1997
Published online:
27
February
2005
Final states with charged kaons in three-prong τ decays are studied by exploiting the particle identification from the dE/dx measurement. The results are based on a sample of about 1.6 × 105 detected τ pairs collected with the ALEPH detector between 1991 and 1995 around the Z peak. The following branching ratios have been measured: B(τ- → K−K+π−ντ) = (1.63 ± 0.21 ± 0.17) × 10−3, B(τ− → K−π+π−ντ) = (2.14 ± 0.37 ± 0.29) × 10−3, B(τ− → K−K+π−π0ντ) = (0.75 ± 0.29 ± 0.15) × 10−3, and B(τ− → K−π+π−π0ντ) = (0.61 ± 0.39 ± 0.18) × 10−3. The first two measurements are more precise than the current world averages, while the last two channels are investigated for the first time. The 95% C.L. upper limit on the branching ratio for the decay τ− → K−K+K−ντ is 0.19 × 10−3. A study of intermediate states occurring in the K−K+π−ντ and K−π+π−ντ decays is also presented.
© Springer-Verlag, 1998