CERN Accelerating science

Differential ${\rm d}\sigma/{\rm d}|\eta_{\ell^+}|$ (left) and ${\rm d}\sigma/{\rm d}|\eta_{\ell^-}|$ (middle) cross section measurements for \Wln\ and ${\rm d}\sigma/{\rm d}|y_Z|$ cross section measurement for \Zll\ (right). The error bars represent the statistical and uncorrelated systematic uncertainties added in quadrature while the theoretical curves are adjusted to the correlated error shifts (see text). The NNLO fit results with free and fixed strangeness are also indicated, and their ratios are shown below the cross section plots.

Differential ${\rm d}\sigma/{\rm d}|\eta_{\ell^+}|$ (left) and ${\rm d}\sigma/{\rm d}|\eta_{\ell^-}|$ (middle) cross section measurements for \Wln\ and ${\rm d}\sigma/{\rm d}|y_Z|$ cross section measurement for \Zll\ (right). The error bars represent the statistical and uncorrelated systematic uncertainties added in quadrature while the theoretical curves are adjusted to the correlated error shifts (see text). The NNLO fit results with free and fixed strangeness are also indicated, and their ratios are shown below the cross section plots.

Differential ${\rm d}\sigma/{\rm d}|\eta_{\ell^+}|$ (left) and ${\rm d}\sigma/{\rm d}|\eta_{\ell^-}|$ (middle) cross section measurements for \Wln\ and ${\rm d}\sigma/{\rm d}|y_Z|$ cross section measurement for \Zll\ (right). The error bars represent the statistical and uncorrelated systematic uncertainties added in quadrature while the theoretical curves are adjusted to the correlated error shifts (see text). The NNLO fit results with free and fixed strangeness are also indicated, and their ratios are shown below the cross section plots.

Predictions for the ratio $r_s = 0.5 (s + \bar{s})/\bar{d}$, at $Q^2=1.9$\,GeV$^2$, $x=0.023$. Points: global fit results using the PDF uncertainties as quoted; bands: this analysis; inner band, experimental uncertainty; outer band, total uncertainty.

Distribution of the light sea quarks, $x\Sigma = 2x (\bar{u} + \bar{d} + \bar{s})$, in the NNLO analysis of HERA and ATLAS data with a fixed fraction of strangeness (lower, green curve) and with a fitted fraction of about unity (upper blue curve). The bands represent the experimental uncertainties.