论文标题
在CEPC上测量光度测量的光束扩展
Beam-spread determination for luminosity measurement at CEPC
论文作者
论文摘要
碰撞光束能量的任何不对称性都将导致撞击颗粒的质量中心框架的纵向增强W.R.T.由于巴巴最终状态的结合性丧失，实验室框架以及腔计的计数损失。在Z0极点运行的CEPC时，碰撞梁的能量的不对称性以及梁孔的12.5％，以控制Bhabha计数的不确定性，水平为0.01％。在这里，我们讨论了最初为FCCEE提出的方法，以从$ e^+e^ - \ toμ^+μ^ - $ collisions中的有效质量中心能量从测量有效的质量中心能量中的变化。
Any asymmetry in energy of the colliding beams will lead to a longitudinal boost of the center-of-mass frame of colliding particles w.r.t. the laboratory frame and consequently to the counting loss in luminometer due to the loss of colinearity of Bhabha final states. At CEPC running at the Z0 pole, asymmetry in energy of the colliding beams should be known as well as 12.5% of the beam-spread, in order to control the uncertainty of Bhabha count at the level of 0.01%. Here we discuss the method, initially proposed for FCCee, to determine variation of the beam-spread from the measurement of the effective center-of-mass energy in $e^+e^- \to μ^+μ^-$ collisions.
