title: Perturbative generation of a strange-quark asymmetry in the nucleon.
abstract: We point out that perturbative evolution in QCD at three loops generates a strange-antistrange asymmetry s(x) - s(x) in the nucleon's sea just from the fact that the nucleon has nonvanishing up and down quark valence densities. The recently computed three-loop splitting functions allow for an estimate of this effect. We find that a fairly sizable asymmetry may be generated. Results for analogous asymmetries in the heavy-quark sector are also presented.
authors.affiliation: INFN, Sezione di Firenze and Dipartimento di Fisica, Università di Firenze, I-50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Catani
authors.forename: Daniel
authors.initials: D
authors.lastname: de Florian
authors.forename: Germán
authors.initials: G
authors.lastname: Rodrigo
authors.forename: Werner
authors.initials: W
authors.lastname: Vogelsang