Fig. 13.

Comparison of the measured differential cross section ratio $R_{\text{c}}^{\pm }$ as a function of the absolute value of ${\eta }^{\ell }$ (upper) and $p_{\text{T}}^{\ell }$ (lower) with the $\text{OS-SS}$ LO, NLO, and NNLO QCD predictions. The NNLO QCD NNPDF3.1 PDF set is used for computing all the predictions. CMPP stands for the authors of the calculations [15]. Error bars on data points include statistical and systematic uncertainties. Symbols showing the theoretical expectations are slightly displaced in the horizontal axis for better visibility. The ratios of data to predictions are shown in the lower panels. The uncertainty in the ratio includes the uncertainties in the data and prediction