Borsa Ignacio, Stratmann Marco, Vogelsang Werner, de Florian Daniel, Sassot Rodolfo
Institute for Theoretical Physics, <a href="https://ror.org/03a1kwz48">University of Tübingen</a>, Auf der Morgenstelle 14, 72076 Tübingen, Germany.
<a href="https://ror.org/05e6n8h53">International Center for Advanced Studies (ICAS)</a>, ICIFI and ECyT-<a href="https://ror.org/00v29jp57">UNSAM</a>, 25 de Mayo y Francia, (1650) Buenos Aires, Argentina.
Phys Rev Lett. 2024 Oct 11;133(15):151901. doi: 10.1103/PhysRevLett.133.151901.
We present a next-to-next-to-leading order (NNLO) global QCD analysis of the proton's helicity parton distribution functions, the first of its kind. To obtain the distributions, we use data for longitudinal spin asymmetries in inclusive and semi-inclusive lepton-nucleon scattering as well as in weak-boson and hadron or jet production in proton-proton scattering. We analyze the data using QCD perturbation theory at NNLO accuracy, employing approximations provided by the threshold resummation formalism in cases where full NNLO results for partonic hard-scattering functions are not readily available. Our numerical results suggest a remarkable perturbative stability of the extracted helicity parton distribution functions.
我们首次展示了对质子螺旋度部分子分布函数的次下一个领头阶（NNLO）全局量子色动力学（QCD）分析。为了获得这些分布，我们使用了在包容性和半包容性轻子 - 核子散射以及质子 - 质子散射中的弱玻色子和强子或喷注产生过程中纵向自旋不对称性的数据。我们在NNLO精度下使用QCD微扰理论分析数据，在部分子硬散射函数的完整NNLO结果不易获得的情况下，采用阈值重整化形式提供的近似。我们的数值结果表明，提取的螺旋度部分子分布函数具有显著的微扰稳定性。
