  We report the direct evidence of impacts of the Coulomb interaction in a
prototypical Weyl semimetal, MoTe2, that alter its bare bands in a wide range
of energy and momentum. Our quasiparticle interference patterns measured using
scanning tunneling microscopy are shown to match the joint density of states of
quasiparticle energy bands including momentum-dependent self-energy
corrections, while electronic energy bands based on the other simpler local
approximations of the Coulomb interaction fail to explain neither the correct
number of quasiparticle pockets nor shape of their dispersions observed in our
spectrum. With this, we predict a transition between type-I and type-II Weyl
fermions with doping and resolve its disparate quantum oscillation experiments,
thus highlighting the critical roles of Coulomb interactions in layered Weyl
semimetals.
