The branching fractions ratio between muon and tau lepton decay modes has shown intriguing discrepancies between the Standard Model prediction and measurements performed at BaBar, Belle, and LHCb experiments, a possible sign of beyond the Standard Model physics. Theoretical studies show how observables related to the differential decay distribution can be used to further constrain New Physics contributions, but their experimental measurements are lacking to date. This article proposes the measurement of angular and -violating observables at hadron collider experiments, by exploiting approximate reconstruction algorithms using information from detectable final-state particles only. The resolution on the phase space variables is studied using decays simulated in a forward detector geometry like LHCb. A method to correct the observable values for the reconstruction inaccuracies based on detector simulation is successfully tested on simulated data and the decrease in precision with respect to a perfect reconstruction is evaluated. The longitudinal polarization fraction and the -violating observable can be measured losing a factor of 2 and 5 in precision, respectively. The extraction of angular distributions from the template fit selecting decays and associated systematic uncertainties are also discussed.

中文翻译：

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强子对撞机实验中的角度和CP破坏分析

的 μ子和tau轻子衰减模式之间的分支分数比率显示出标准模型预测与在BaBar，Belle和LHCb实验中进行的测量之间的有趣差异，这可能是超出标准模型物理学的可能迹象。理论研究表明，可观测值与差分衰减分布可用于进一步限制“新物理学”的贡献，但迄今为止尚缺乏它们的实验测量。本文提出了测量角和-在强子对撞机实验违反可观测量，通过利用使用从唯一可检测到最终状态的颗粒信息近似重建算法。使用以下方法研究相空间变量的分辨率在LHCb等前向检测器几何中模拟的衰减。在模拟数据上成功测试了一种基于检测器仿真的可纠正重构误差的可观察值的方法，并评估了相对于完美重构的精度下降。的纵向极化馏分和-violating可观察到的，可以分别测量精度失去2和5倍。从模板拟合选择中提取角度分布 衰减和相关的系统不确定性也进行了讨论。