According to the path-integral formalism of the hadronic tensor, the nucleon sea contains two distinct components called the connected sea (CS) and the disconnected sea (DS). We discuss how the CS and DS are accessed in the lattice QCD calculation of the moments of the parton distributions. We show that the CS and DS components of $\overline{u}(x)+\overline{d}(x)$ can be extracted by using recent data on the strangeness parton distribution, the CT10 global fit, and the lattice result of the ratio of the strange to $u(d)$ moments in the disconnected insertion. The extracted CS and DS for $\overline{u}(x)+\overline{d}(x)$ have a distinct Bjorken $x$ dependence in qualitative agreement with expectation. The analysis also shows that the momentum fraction of $\overline{u}(x)+\overline{d}(x)$ is about equally divided between the CS and DS at $Q^2=2.5{\mathrm{GeV}}^2$. Implications for the future global analysis of parton distributions are presented.

• Received 21 June 2012

DOI:https://doi.org/10.1103/PhysRevLett.109.252002