标题： 在 $e^+e^-\toτ^+τ^-$ 中检验 $(g-2)_τ$：Belle II 的辐射修正和预测 显示英文标题

标题： Towards testing $(g-2)_τ$ in $e^+e^-\toτ^+τ^-$: radiative corrections and projections for Belle II

摘要： 迄今为止最有希望通过检验标准模型之外的物理方法来测试$\tau$的反常磁矩，是通过在极化电子束存在的情况下，在$e^+e^-\to\tau^+\tau^-$中构建合适的不对称性来实现的。这一计划，假设在超级KEKB$e^+e^-$对撞机上实现了极化升级，可以在贝尔II实验中实现，关键在于仔细考虑辐射修正。在这项工作中，我们展示了完全极化的$e^+e^-\to\tau^+\tau^-$过程的一圈完整结果及其在蒙特卡洛积分器McMule中的实现。作为应用，我们讨论了与贝尔II测量相关的预测，包括有无电子极化的情况，并概述了推广到次次领头阶的必要步骤。 显示英文摘要

摘要： The arguably most promising avenue towards testing physics beyond the Standard Model in the anomalous magnetic moment of the $\tau$ proceeds via suitably constructed asymmetries in $e^+e^-\to\tau^+\tau^-$ in the presence of a polarized electron beam. Such a program, as could be realized at Belle II assuming a polarization upgrade of the SuperKEKB $e^+e^-$ collider, crucially relies on a careful consideration of radiative corrections. In this work, we present the complete one-loop result for the fully polarized $e^+e^-\to\tau^+\tau^-$ process and its implementation in the Monte-Carlo integrator McMule. As an application, we discuss projections relevant for measurements at Belle II, both with and without electron polarization, and outline the necessary steps for a generalization to next-to-next-to-leading order.