The decay of the muon has been studied at PSI with several precision measurements: The longitudinal polarization PL(E) with the muon decay parameters ξ′, ξ′′, the Time- Reversal Invariance (TRI) conserving transverse polarization PT1(E) with the muon de- cay parameters η, η′′, the TRI violating transverse polarization PT2(E), with α′/A, β′/A and the muon decay asymmetry with Pμξ. The detailed theoretical analysis of all mea- surements of normal and inverse muon decay has led for the first time to a lower limit |g V | > 0.960 ("V − A") and upper limits for nine other possible complex couplings, espe- cially the scalar coupling |g S | < 0.550 which had not been excluded before.

中文翻译：

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介子衰变

已经在 PSI 研究了 μ 子的衰变，并进行了多项精确测量：具有 μ 子衰变参数 ξ'、ξ'' 的纵向偏振 PL(E)，具有横向偏振 PT1(E) 的时间反转不变性 (TRI) μ子衰变参数η，η''，TRI违反横向极化PT2(E)，具有α'/A，β'/A，μ子衰变与Pμξ不对称。对正常和反介子衰变所有测量的详细理论分析首次导致了下限 |g V | > 0.960（“V - A”）和其他九种可能的复杂耦合的上限，特别是标量耦合 |g S | < 0.550 之前没有被排除在外。