"Figure 8 (the ratio of simulation and data)" of "Longitudinal double-spin asymmetry for inclusive jet and dijet production in $pp$ collisions at $\sqrt{s} = 510$ GeV"

We report the first measurement of the inclusive jet and the dijet longitudinal double-spin asymmetries, ALL, at midrapidity in polarized pp collisions at a center-of-mass energy s√=510 GeV. The inclusive jet ALL measurement is sensitive to the gluon helicity distribution down to a gluon momentum fraction of x≈0.015, while the dijet measurements, separated into four jet-pair topologies, provide constraints on the x dependence of the gluon polarization. Both results are consistent with previous measurements made at s√=200 GeV in the overlapping kinematic region, x>0.05, and show good agreement with predictions from recent next-to-leading order global analyses.

本工作首次报道了质心系能量√s=510 GeV的极化质子-质子（pp）碰撞中，中快度区单举喷注与双喷注的纵向双自旋不对称性A_LL（longitudinal double-spin asymmetries, A_LL）的测量结果。单举喷注的A_LL测量对胶子动量份额x≈0.015处的胶子螺旋度分布具有敏感性；而被划分为四种喷注对拓扑结构的双喷注测量，则可约束胶子极化随x的依赖关系。两项结果均与此前在√s=200 GeV、运动学重叠区域x>0.05内完成的测量结果一致，且与近期次领头阶整体分析的理论预言吻合良好。