The flavor asymmetry of the light quark sea of the nucleon is determined in the kinematic range 0.02 < x < 0.3 and 1 < Q2 < 10GeV2 for the first time from semi-inclusive deep-inelastic scattering. The quantity [d¯(x)- ¯u(x)]/[u(x)-d(x)] is derived from a relationship between the yields of positive and negative pions from unpolarized hydrogen and deuterium targets. The flavor asymmetry d¯ - u¯ is found to be nonzero and x dependent, showing an excess of d¯ over u¯ quarks in the proton.
ASJC Scopus subject areas
- Physics and Astronomy(all)