摘要： Difference between the u¯ and d¯ sea quark distributions in the proton was first observed in the violation of the Gottfried sum rule in deep-inelastic scattering (DIS) experiments. The parton momentum fraction x dependence of this difference has been measured over the region 0.02<x<0.35 from Drell–Yan and semi-inclusive DIS experiments. The Drell–Yan data suggested a possible sign-change for d¯(x)−u¯(x) near x∼0.3, which has not yet been explained by existing theoretical models. We present an independent evidence for the d¯(x)−u¯(x) sign-change at x∼0.3 from an analysis of the DIS data. We further discuss the x-dependence of d¯−u¯ in the context of meson cloud model and the lattice QCD formulation. 出版者： United States: Elsevier B.V 出版日期： 2014-09-07 出處： Physics Letters B, 2014-09, Vol.736 (C), p.411-414 資源來源： Elsevier ScienceDirect Journals 版權： 2014 The Authors 識別號： ISSN: 0370-2693 識別號： ISSN: 1873-2445 識別號： EISSN: 1873-2445 識別號： DOI: 10.1016/j.physletb.2014.07.050
