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Published on: November 15, 2013
在全球PDF合适的LO顺序中初次确定强合在近似顺序中
T Cridge1, L A Harland-Lang2, R S Thorne2
1Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.
我们使用质子和分子分布函数 (PDF) 确定了强连接常数,以大致的下一个领先顺序. 该值与以前的NNLO结果一致,显示出良好的趋同,并提供更准确的不确定性.
科学领域:
- 高能物理 高能物理
- 量子色态动力学 (QCD) 是一个
- 帕顿分布函数 (PDF) 的使用方法
背景情况:
- 强合常数 ($\alpha_s$) 是QCD的一个基本参数.
- 以前的确定通常依赖于NNLO计算.
- 理论计算的进步使得近似的NLO顺序适合.
研究的目的:
- 为了确定强合常数 ($\alpha_s$) 的值,使用全球适合的质子PDFs.
- 在MSHT框架内以近似的NLO顺序执行此确定.
- 分析不同数据集,特别是二次流与包容性喷气数据对强合值的影响.
主要方法:
- 质子部分分布函数 (PDF) 的同时全球合适.
- 使用MSHT全球PDF安装框架.
- 在QCD中以近似的NLO (aNLO) 顺序执行匹配,并纳入最近的理论进展.
主要成果:
- 强连接常数被确定为 $\alpha_s(M_Z^2) = 0.1184 \pm 0.0015$ (aNLO).
- 这个值与NNLO的$\alpha_s(M_Z^2) = 0.1172 \pm 0.0007$的确定非常一致.
- 在aNLO的不确定性较大,但由于包含缺失的更高阶理论不确定性,因此更准确.
结论:
- 在aNLO和NNLO之间观察到强合常数的良好扰动趋同.
- aNLO的确定提供了更准确的不确定性评估.
- 在dijet和inclusive喷气数据之间做出选择具有不可忽视的影响,但整体一致性得到维护,特别是在aNLO.
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