PDF fit in the fixed-flavor-number scheme

We discuss the heavy-quark contribution to deep-inelastic scattering in the scheme with nf=3,4,5 fixed flavors. Based on the recent ABM11 PDF analysis of world data for deep-inelastic scattering and fixed-target data for the Drell-Yan process with the running-mass definition for heavy quarks, we show that the fixed flavor number scheme is sufficient for describing the deep-inelastic-scattering data in the entire kinematic range. We compare with other PDF sets and comment on the implications for measuring the strong coupling constant αs(MZ).