Measurement of the {tau}{sup -}{yields}{eta}{pi}{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}} branching fraction and a search for a second-class current in the {tau}{sup -}{yields}{eta}{sup '}(958){pi}{sup -}{nu}{sub {tau}} decay

Journal Article · Sun Jun 01 00:00:00 EDT 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.77.112002· OSTI ID:21205042

Aubert, B; Bona, M; Boutigny, D; Karyotakis, Y; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A ^[1]; Tico, J Garra; Grauges, E ^[2]; Lopez, L; Palano, A; Pappagallo, M ^[3]; Eigen, G; Stugu, B; Sun, L ^[4]; Abrams, G S; Battaglia, M; Brown, D N ^[5]

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1. Laboratoire de Physique des Particules, IN2P3/CNRS et Universite de Savoie, F-74941 Annecy-Le-Vieux (France)
2. Universitat de Barcelona, Facultat de Fisica, Departament ECM, E-08028 Barcelona (Spain)
3. Universita di Bari, Dipartimento di Fisica and INFN, I-70126 Bari (Italy)
4. University of Bergen, Institute of Physics, N-5007 Bergen (Norway)
5. Lawrence Berkeley National Laboratory and University of California, Berkeley, CA 94720 (United States)

The {tau}{sup -}{yields}{eta}{pi}{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}} decay with the {eta}{yields}{gamma}{gamma} mode is studied using 384 fb{sup -1} of data collected by the BABAR detector. The branching fraction is measured to be (1.60{+-}0.05{+-}0.11)x10{sup -4}. It is found that {tau}{sup -}{yields}f{sub 1}(1285){pi}{sup -}{nu}{sub {tau}}{yields}{eta}{pi}{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}} is the dominant decay mode with a branching fraction of (1.11{+-}0.06{+-}0.05)x10{sup -4}. The first error on the branching fractions is statistical and the second systematic. Note that no particle identification algorithm is applied to the charged tracks to distinguish pions from kaons. In addition, a 90% confidence level upper limit on the branching fraction of the {tau}{sup -}{yields}{eta}{sup '}(958){pi}{sup -}{nu}{sub {tau}} decay is measured to be 7.2x10{sup -6}. This last decay proceeds through a second-class current and is expected to be forbidden in the limit of isospin symmetry.

• OSTI ID: 21205042
• Journal Information: Physical Review. D, Particles Fields, Vol. 77, Issue 11; Other Information: DOI: 10.1103/PhysRevD.77.112002; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ALGORITHMS
BRANCHING RATIO
DECAY
ETA MESONS
ISOSPIN
PARTICLE DECAY
PARTICLE IDENTIFICATION
PARTICLE TRACKS
PIONS MINUS
PIONS NEUTRAL
PIONS PLUS
SECOND-CLASS CURRENTS
SYMMETRY
TAU NEUTRINOS
TAU PARTICLES