  We study charm production in charged-current deep-inelastic scattering (DIS)
using the xFitter framework. Recent results from the LHC have focused renewed
attention on the determination of the strange-quark parton distribution
function (PDF) and the DIS charm process provides important complementary
constraints on this quantity. We examine the current PDF uncertainty, and use
LHeC pseudodata to estimate the potential improvement from this proposed
facility. As xFitter implements both fixed-flavor- and variable-flavor-number
schemes, we can compare the impact of these different theoretical choices; this
highlights some interesting aspects of multi-scale calculations. We find that
the high-statistics LHeC data covering a wide kinematic range could
substantially reduce the strange PDF uncertainty.

High Energy Physics - Phenomenology