  Stacking monolayer semiconductors results in moir\'e patterns that host many
correlated and topological electronic phenomena, but measurements of the basic
electronic structure underpinning these phenomena are scarce. Here, we
investigate the properties of the conduction band in moir\'e heterobilayers
using submicron angle-resolved photoemission spectroscopy with electrostatic
gating, focusing on the example of WS2/WSe2. We find that at all twist angles
the conduction band edge is the K-point valley of the WS2, with a band gap of
1.58 +- 0.03 eV. By resolving the conduction band dispersion, we observe an
unexpectedly small effective mass of 0.15 +- 0.02 m_e. In addition, we observe
replicas of the conduction band displaced by reciprocal lattice vectors of the
moir\'e superlattice. We present arguments and evidence that the replicas are
due to modification of the conduction band states by the moir\'e potential
rather than to final-state diffraction. Interestingly, the replicas display an
intensity pattern with reduced, 3-fold symmetry, which we show implicates the
pseudo vector potential associated with in-plane strain in moir\'e band
formation.
