# Search for the Decay $\tau^- \to 3\pi^- 2\pi^+ 2\pi^0 \nu_\tau$

Abstract : A search for the decay of the tau lepton to five charged and two neutral pions is performed using data collected by the BABAR detector at the PEP-II asymmetric-energy e+e- collider. The analysis uses 232 fb-1 of data at center-of-mass energies on or near the Y(4S) resonance. We observe 10 events with an expected background of 6.5^{+2.0}_{-1.4} events. In the absence of a signal, we set the limit on the branching ratio B(tau- --> 3pi- 2pi+ 2pi0 nu_tau) < 3.4x10^{-6} at the 90% confidence level. This is a significant improvement over the previously established limit. In addition, we search for the decay mode tau- --> 2omega pi- nu_tau. We observe 1 event with an expected background of 0.4^{+1.0}_{-0.4} events and calculate the upper limit B(tau- --> 2omega pi- nu_tau) < 5.4x10^{-7} at the 90% confidence level. This is the first upper limit for this mode.
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http://hal.in2p3.fr/in2p3-00084548
Contributor : Claudine Bombar <>
Submitted on : Thursday, January 11, 2007 - 2:47:50 PM
Last modification on : Wednesday, September 16, 2020 - 4:25:14 PM

### Citation

B. Aubert, R. Barate, D. Boutigny, F. Couderc, Y. Karyotakis, et al.. Search for the Decay $\tau^- \to 3\pi^- 2\pi^+ 2\pi^0 \nu_\tau$. Physical Review D, American Physical Society, 2006, 73, pp.112003. ⟨10.1103/PhysRevD.73.112003⟩. ⟨in2p3-00084548⟩

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