论文标题
使用辐射回报在ILC 250的$ a_ {lr} $的测量
Measurement of $A_{LR}$ using radiative return at ILC 250
论文作者
论文摘要
对于ILC 250的精确研究，$ a_ {lr} $的测量很重要，因为它可以约束SMEFT参数。当前最佳测量的$ a_ {lr} $ value是$ a_ {lr} = 0.1514 \ pm 0.0019 \，（stat）\ pm 0.0011 \，（syst）$，在SLC上测量，并且需要更精确的值才能在Tev-Scale中进行全球物理搜索。在ILC，我们可以使用$ e^+ e^ - \到γz$进程来评估$ a_ {lr} $。我们对250 GEV的质量中心能量进行了$ e^+ e^ - \至γz$过程的完整模拟研究，并评估了我们可以提高可观察到的精度的程度。 $ a_ {lr} $在ILC 250上的统计错误结果为$ 1.8 \ times 10^{ - 4} $。系统误差的主要来源是光束极化中的误差。作为系统误差的其他来源，每种极化组合的光度和选择效率的乘积误差的不相关部分都会促进。包括那些系统的错误，$ a_ {lr} $上的总绝对错误估计为0.00025，精度是SLC（0.00219）的精度8.8倍。
For the precision study at the ILC 250, measurement of $A_{LR}$ is important as it can constrain SMEFT parameters. The current best measured $A_{LR}$ value is $A_{LR} = 0.1514 \pm 0.0019\,(stat) \pm 0.0011\,(syst)$ which was measured at the SLC, and a more precise value is required for the global fit for the new physics search in TeV-scale. At the ILC, we can use the $e^+ e^- \to γZ$ process to evaluate the $A_{LR}$. We performed a full simulation study of the $e^+ e^- \to γZ$ process at the center-of-mass energy of 250 GeV and evaluated how much we can improve the precision of this observable. The statistical error on $A_{LR}$ at the ILC 250 turned out to be $1.8 \times 10^{-4}$. Major source of the systematic error was error from the beam polarization. As other sources of the systematic error, the uncorrelated parts of error on the product of luminosity and selection efficiency for each polarization combination contribute. Including those systematic errors, total absolute error on $A_{LR}$ was estimated to be 0.00025, 8.8 times better precision than that from the SLC (0.00219).
