Evidence for the $\tau\to $Neutrino $\rho\pi$ decay mode

• Main Authors: Alexander, G., Criegee, L., Dehne, H. C., Derikum, K., Devenish, R., Flugge, G., Fox, J. D., Franke, G., Gerke, Christian, Hackmack, E., Harms, P., Horlitz, G., Kahl, T., Knies, G., Lehmann, E., Rossler, M., Schmitz, R., Timm, U., Waloschek, P., Winter, G. G., Wolff, S., Zimmermann, W., Wagner, W., Blobel, V., Garfinkel, A. F., Koppitz, B., Lohrmann, E., Luhrsen, W., Backer, A., Burger, J., Grupen, C., Meyer, H., Wacker, K.
• Format: Report
• Language: English
• Subjects: 6-5 GEV-CM; ANNIHILATION: ELECTRON POSITRON; COLLIDING BEAMS: ELECTRON POSITRON; DESY DORIS STOR; ELECTRON POSITRON > > TAU+ TAU; ELECTRON POSITRON: ANNIHILATION; ELECTRON POSITRON: COLLIDING BEAMS; ELECTRON: FINAL STATE; ELECTROPRODUCTION: HEAVY LEPTON; EXPERIMENTAL RESULTS; FINAL STATE: ELECTRON; FINAL STATE: NEUTRINO; FINAL STATE: PI; HEAVY LEPTON: ELECTROPRODUCTION; HEAVY LEPTON: LEPTONIC DECAY; HEAVY LEPTON: NONLEPTONIC DECAY; HEAVY LEPTON: PAIR PRODUCTION; LEPTONIC DECAY: HEAVY LEPTON; MASS SPECTRUM: (3PI); NEUTRINO: FINAL STATE; NONLEPTONIC DECAY: HEAVY LEPTON; PAIR PRODUCTION: HEAVY LEPTON; PI: FINAL STATE; PLUTO; RHO0; TAU > > ELECTRON 2NEUTRINO; TAU+ > > RHO0 PI NEUTRINO; TAU: BRANCHING RATIO
• ISSN: 1873-2445; 0370-2693
• DOI: 10.3204/pubdb-2017-12303

Annihilation of e + e − into final states with a single electron has been studied with the PLUTO detector at the DORIS storage ring at CMS energies from 3.6 to 5 GeV. In the sample of 4-prong events without any detected photon we observe 21 events which we assign to the reaction e + e − → τ + τ − → νν e + νϱ 0 π . We obtain a branching ratio for τ + → νϱ 0 π + of 0.050 ± 0.015 with an overall systematic uncertainty of 30%. The data are consistent with the ϱπ coming from an A 1 meson.