全球PDF的压力测试符合:关闭测试MSHT的PDF,并与神经网络方法进行首次直接比较
L A Harland-Lang1, T Cridge2, R S Thorne1
1Department of Physics and Astronomy, University College London, London, WC1E 6BT UK.
The European physical journal. C, Particles and fields
|March 21, 2025
概括
MSHT20参数化准确地重现了闭合测试中的数据,没有显示任何不灵活性. 与NNPDF相适应的直接比较揭示了MSHT.
科学领域:
- 高能物理 高能物理
- 量子色态动力学 量子色态动力学
- 粒子物理学 粒子物理学
背景情况:
- 全球帕顿分布函数 (PDF) 匹配对于理解质子结构至关重要.
- MSHT和NNPDF的合作代表了PDF确定的主要方法.
- 评估参数化选择和合适方法的影响对于稳固的PDF结果至关重要.
研究的目的:
- 执行MSHT固定的参数化方法的第一个全球关闭测试.
- 进行MSHT和NNPDF安装方法之间的直接,相似的比较.
- 调查参数化灵活性和容忍标准对PDF安装结果的影响.
主要方法:
- 使用MSHT20固定的参数化进行了全球关闭测试.
- 使用NNPDF4.0数据和理论输入生成了一个新的匹配,但使用MSHT固定的参数化.
- 在方法之间比较了匹配的质量,PDF的不确定性和基准横截面.
主要成果:
- 默认的MSHT20参数化在预期的不确定性范围内成功地重现了关闭测试中的输入数据.
- 当应用到NNPDF数据时,MSHT参数化产生了比标准NNPDF4.0匹配更好的匹配质量.
- 观察到MSHT和NNPDF之间不确定性估计的差异,突出了装配公差的潜在不一致性.
结论:
- 在MSHT20中参数化的不灵活性在测试数据区域内不是一个重要的问题.
- 选择合适的方法和参数化显著影响PDF的确定和相关的不确定性.
- 为了获得一致可靠的结果,需要对全球PDF匹配中的耐受性标准进行批判性评估.
相关概念视频
01:13Multiple Comparison Tests
Multiple comparison test, abbreviated as MCT, is a post hoc analysis generally performed after comparing multiple samples with one or more tests. An MCT will help identify a significantly different sample among multiple samples or a factor among multiple factors.
It would be easy to compare two samples using a significance alpha level of 0.05. In other words, there is only one sample pair to be compared. However, it would be difficult to identify a significantly different sample if the number...
It would be easy to compare two samples using a significance alpha level of 0.05. In other words, there is only one sample pair to be compared. However, it would be difficult to identify a significantly different sample if the number...
01:12Non-destructive Tests for Concrete Strength
The rebound hammer test, also known as the Schmidt hammer test, is a non-destructive technique for evaluating the hardness of concrete and, indirectly, the strength of concrete. It operates on the principle that the rebound of a spring-driven mass from a concrete surface correlates to the surface's hardness. The device comprises a mass within a tubular housing, a spring mechanism, and a plunger that strikes the concrete. Upon release, the energy imparted to the mass by the spring causes it to...