当前位置: X-MOL 学术Phys. Rev. C › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
How analytic choices can affect the extraction of electromagnetic form factors from elastic electron scattering cross section data
Physical Review C ( IF 3.1 ) Pub Date : 2020-07-10 , DOI: 10.1103/physrevc.102.015205
Scott K. Barcus , Douglas W. Higinbotham , Randall E. McClellan

Scientists often try to incorporate prior knowledge into their regression algorithms, such as a particular analytic behavior or a known value at a kinematic endpoint. Unfortunately, there is often no unique way to make use of this prior knowledge, and thus, different analytic choices can lead to very different regression results from the same set of data. To illustrate this point in the context of the proton electromagnetic form factors, we use the Mainz elastic data with its 1422 cross section points and 31 normalization parameters. Starting with a complex unbound non-linear regression, we will show how the addition of a single theory-motivated constraint removes an oscillation from the magnetic form factor and shifts the extracted proton charge radius. We then repeat both regressions using the same algorithm, but with a rebinned version of the Mainz dataset. These examples illustrate how analytic choices, such as the function that is being used or even the binning of the data, can dramatically affect the results of a complex regression. These results also demonstrate why it is critical when using regression algorithms to have either a physical model in mind or a firm mathematical basis

中文翻译:

分析选择如何影响从弹性电子散射截面数据中提取电磁形状因子

科学家们经常尝试将先验知识整合到他们的回归算法中,例如特定的分析行为或运动学端点的已知值。不幸的是,通常没有独特的方法来利用这种先验知识,因此,不同的分析选择可能会导致来自同一组数据的非常不同的回归结果。为了在质子电磁形状因子的上下文中说明这一点,我们使用 Mainz 弹性数据及其 1422 个横截面点和 31 个归一化参数。从复杂的未绑定非线性回归开始,我们将展示添加单个理论驱动的约束如何消除磁性形状因子的振荡并改变提取的质子电荷半径。然后我们使用相同的算法重复两个回归,但使用美因茨数据集的重新组合版本。这些示例说明了分析选择(例如正在使用的函数甚至数据的分箱)如何显着影响复杂回归的结果。这些结果还说明了为什么在使用回归算法时考虑物理模型或牢固的数学基础是至关重要的
更新日期:2020-07-10
down
wechat
bug