Measurement of the weak dipole moments of the tau lepton

Using the data collected by the L3 experiment at LEP from 1991 to 1995 at energies around the Z mass, a measurement of the weak anomalous magnetic dipole moment, a w τ , and of the weak electric dipole moment, d w τ , of the τ lepton is performed. These quantities are obtained from angular distributions in e + e − →τ + τ − →h + ν ̄ τ h − ν τ , where h is a π or a ρ . The results are: Re ( a w τ )=(0.0±1.6±2.3)×10 −3 , Im ( a w τ )=(−1.0±3.6±4.3)×10 −3 and Re ( d w τ )=(−0.44±0.88±1.33)×10 −17 e ·cm. This is the first direct measurement of a w τ .

electron positron: colliding beams
electron positron: annihilation
Z0: electroproduction
tau: pair production
tau: magnetic moment
tau: electric moment
weak interaction: moment
tau: semileptonic decay
L3
experimental results

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Figures(0)

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