Nucleon sea and the five-quark components

Abstract

We generalize the approach of Brodsky {\it et al.} for the intrinsic charm quark distribution in the nucleons to the light-quark sector involving intrinsic $\bar{u},\bar{d},s$ and $\bar{s}$ sea quarks. We compare the calculations with the existing $\bar{d}-\bar{u}$, $s+\bar{s}$, and $\bar{u}+\bar{d}-s-\bar{s}$ data. The good agreement between the theory and the data is interpreted as evidence for the existence of the intrinsic light-quark sea in the nucleons. The probabilities for the $|uudu\bar{u}>$, $|uudd\bar{d}>$ and $|uuds\bar{s}>$ Fock states are also extracted.

Comments: 8 pages, 4 figures. Plenary talk at the QNP2012 Conference