# The decay $\tau \rightarrow 3\pi\nu_{\tau}$, as a probe of the mechanism of dynamical chiral symmetry breaking

Abstract : The decays tau --> 3 pi + nu(tau) are analyzed at one loop order in the framework of Generalized Chiral Perturbation Theory, in order to test the sensitivity to the size of spontaneous chiral symmetry breaking parameters, contained in the S-wave. The latter, due to a kinematical suppression, at threshold, of the P-wave, is relatively large enough to be detectable at high-energy machines, through azimuthal left-right asymmetries. This quantity (for the pi(-) pi(-) pi(+) mode), integrated from threshold to Q(2) = 0.35 GeV2, varies from (17 +/- 3)% in the standard case of large condensate up to (40 +/- 5)% in the extreme case of tiny condensate. The feasibility of such measurement at high luminosity colliders (e.g., CLEO) is discussed. This method provides an independent cross-check of forthcoming experimental determination of the two-light-flavor chiral condensate, based on low-energy pi pi scattering
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Journal articles

http://hal.in2p3.fr/in2p3-00006035
Contributor : Suzanne Robert <>
Submitted on : Tuesday, September 12, 2000 - 12:49:10 PM
Last modification on : Wednesday, September 16, 2020 - 4:00:28 PM

### Citation

L. Girlanda, J. Stern. The decay $\tau \rightarrow 3\pi\nu_{\tau}$, as a probe of the mechanism of dynamical chiral symmetry breaking. Nuclear Physics B, Elsevier, 2000, 575, pp.285-312. ⟨in2p3-00006035⟩

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