The flavour asymmetry and quark-antiquark asymmetry in the Σ+-sea

The sea quark content of the Sigma(+) baryon is investigated using light-cone baryon-meson fluctuation model suggested by Brodsky and Ma. It is found that the Sigma(+) sea is flavour asymmetric ((d) over bar>(u) over bar>(s) over bar) and quark-antiquark asymmetric (q not equal (q) over bar). Our prediction for the flavour asymmetry, (d) over bar>(u) over bar>(s) over bar, is significantly different from the SU(3) prediction ((d) over bar<(u) over bar<(s) over bar), while our prediction for the d-(d) over bar asymmetry is consistent with the SU(3) prediction. (C) 2000 Elsevier Science B.V. All rights reserved.