通过τ→a_1v→π~±π~0π~0v道测量由Z^0衰变的τ的极化不对称性

Measurement of the τ Polarization Asymmetry in τ→a_1 v→π~± π~0 π~0 v Decay at Z^0 Peak

利用L3合作组1992年和1993年的数据，通过τ→a1v→π±π0π0v道测量了由Z0衰变的τ的极化不对称性A(pol)＝－0．239±0．126±0．100，其中第一项误差为统计误差，第二项误差为系统误差．由此推断有效电弱混合角sin2θw＝0．2197±0．0219．

The τ polarization asymmetry in τ→a1 v→π±π0 π0 v decay at Z0 peak is measured using data collected by L3 detector at LEP in 1992 and 1993, Apol=-0.239± 0.126±0.100, where the first error is statistical and the second systematic. And the effective electroweak mixing angle sin2θw = 0.2197 ±0.0219 is derived.