  We study the detector performance in the reconstruction of
hadronically-decaying W bosons and Higgs bosons at very high energy proton
colliders using a full GEANT4 simulation of the SiFCC detector. The W and Higgs
bosons carry transverse momentum in the multi-TeV range, which results in
collimated decay products that are reconstructed as a single jet. We present a
measurement of the energy response and resolution of boosted W-jets and
Higgs-jets and show the separation of two sub-jets within the boosted boson
jet.
