The beam energy of the circular electron-positron collider should be measured precisely to the order of 1 MeV, in order to decrease the uncertainty of the Higgs/W/Z bosons' mass measurement. For this purpose, a lepton bunch is extracted from the collider and collides with an Yttrium-Aluminum-Garnet laser pulse. After the inverse Compton scattering, the main beam and the scattered beam pass through an analytical magnetic field and are deflected to different angles. At the end of the drift beam pipes, the deflecting distances are detected with the spatial resolution of several microns. The systematic uncertainties caused by the detector arrangement, the magnetic field, the angle between the detector plane and the incident beam, and the synchrotron radiation are discussed in detail. The simulations of the statistical errors are given with a toy Monte Carlo sample. With some proper corrections, the beam energy uncertainty of the Higgs mode is around 2 MeV. Our method is applicable to different operating modes of the collider.

中文翻译：

---

基于康普顿散射和束流跟踪方法的圆形正负电子对撞机束能量测量

圆形电子-正电子对撞机的束能量应精确测量到 1 MeV 量级，以降低希格斯/W/Z 玻色子质量测量的不确定性。为此，从对撞机中提取轻子束并与钇-铝-石榴石激光脉冲碰撞。在逆康普顿散射之后，主光束和散射光束通过一个解析磁场并偏转到不同的角度。在漂移束管的末端，偏转距离以几微米的空间分辨率被检测到。详细讨论了由探测器布置、磁场、探测器平面与入射光束之间的角度以及同步辐射引起的系统不确定性。统计误差的模拟是用一个玩具蒙特卡罗样本给出的。通过一些适当的修正，希格斯模式的束能量不确定性约为 2 MeV。我们的方法适用于对撞机的不同工作模式。