Barry P C, Ji Chueng-Ryong, Sato N, Melnitchouk W
Jefferson Lab, Newport News, Virginia 23606, USA.
Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA.
Phys Rev Lett. 2021 Dec 3;127(23):232001. doi: 10.1103/PhysRevLett.127.232001.
We perform the first global QCD analysis of pion valence, sea quark, and gluon distributions within a Bayesian Monte Carlo framework with threshold resummation on Drell-Yan cross sections at next-to-leading log accuracy. Exploring various treatments of resummation, we find that the large-x asymptotics of the valence quark distribution ∼(1-x)^{β_{v}} can differ significantly, with β_{v} ranging from ≈1 to >2.5 at the input scale. Regardless of the specific implementation, however, the resummation induced redistribution of the momentum between valence quarks and gluons boosts the total momentum carried by gluons to ≈40%, increasing the gluon contribution to the pion mass to ≈40 MeV.
我们在贝叶斯蒙特卡罗框架内，对π介子价夸克、海夸克和胶子分布进行了首次全球量子色动力学分析，在次领先对数精度下对德雷尔-杨截面进行阈值重整化。通过探索重整化的各种处理方法，我们发现价夸克分布的大x渐近行为∼(1 - x)^β_v可能有显著差异，在输入尺度下β_v的范围从约1到大于2.5。然而，无论具体的实现方式如何，重整化引起的价夸克和胶子之间动量的重新分布将胶子携带的总动量提高到约为40%，使胶子对π介子质量的贡献增加到约40 MeV。
