Abstract

Measurement of the effective weak mixing angle \({\theta_{\textrm{eff}}}\) in an experiment at the Super Charm Tau Factory is discussed for the case of a longitudinal polarization of electrons. A method for measuring the average electron beam polarization by means of analyzing the differential cross section for the decay process \({{J/\psi}}\to[\Lambda\to p\pi^{-}][{\bar{\Lambda}}\to{\bar{p}}\pi^{+}]\) is proposed. At a collider luminosity of \(10^{35}\textrm{cm}^{-2}\textrm{s}^{-1}\) and a polarization degree of \(0.8\), the parameter \({\sin^{2}{{\theta_{\textrm{eff}}}}}\) can be measured to a relative precision better than \(1\%\), which will be sufficient for observing the deviation of \({\sin^{2}{{\theta_{\textrm{eff}}}}}\) from its value at the \(Z\)-boson peak.

中文翻译：

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在超级魅力头工厂的偏振光束实验中测量温伯格角

摘要

有效弱混角的测量\（{\ THETA _ {\ TEXTRM {EFF}}} \）在超级魅力头厂的实验是为电子的纵向极化的情况下讨论的。一种用于通过分析所述差分截面的衰变过程来测量的平均电子束偏振法[{\巴- \（{{焦耳/ \ PSI}} \到[{} \ LAMBDA \至p \ PI ^]建议{\ Lambda}}到{\ bar {p}} \ pi ^ {+}] \）。在对撞机亮度\（10 ^ {35} \ textrm {cm} ^ {-2} \ textrm {s} ^ {-1} \）和偏振度\（0.8 \）下，参数\（{ \ sin ^ {2} {{\\ t​​heta _ {\ textrm {eff}}}}}} \）的相对精度可以优于\（1 \％\），这足以观察\（{\ sin ^ {2} {{\ theta _ {\ textrm {eff}}}}}} \）与\（Z \）-玻色子峰值处的值的偏差。