We present a new measurement of the tau neutrino helicity h(nu tau) and the tau Michel parameters rho, eta, xi, and the product delta xi. The analysis exploits the highly polarized SLC electron beam to extract these quantities directly from a measurement of the tau decay spectra, using the 1993-1995 SLD data sample of 4328 e(+)e(-) --> Z(0) --> tau(+)tau(-) events. From the decays tau --> pi nu(tau) and tau --> rho nu(tau) we obtain a combined value h(nu tau) = -0.93 +/- 0.10 +/- 0.04. The leptonic decay channels yield combined values of rho = 0.72 +/- 0.09 +/- 0.03, xi = 1.05 +/- 0.35 +/- 0.04, and delta xi = 0.88 +/- 0.27 +/- 0.04.

Measurement of the tau neutrino helicity and Michel parameters in polarized e(+)e(-) collisions

BISELLO, DARIO;
1997

Abstract

We present a new measurement of the tau neutrino helicity h(nu tau) and the tau Michel parameters rho, eta, xi, and the product delta xi. The analysis exploits the highly polarized SLC electron beam to extract these quantities directly from a measurement of the tau decay spectra, using the 1993-1995 SLD data sample of 4328 e(+)e(-) --> Z(0) --> tau(+)tau(-) events. From the decays tau --> pi nu(tau) and tau --> rho nu(tau) we obtain a combined value h(nu tau) = -0.93 +/- 0.10 +/- 0.04. The leptonic decay channels yield combined values of rho = 0.72 +/- 0.09 +/- 0.03, xi = 1.05 +/- 0.35 +/- 0.04, and delta xi = 0.88 +/- 0.27 +/- 0.04.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/2520388
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