  We suggest that Bose-Einstein condensates in optical lattices subjected to ac
forcing with a smooth envelope may provide detailed experimental access to
multiphoton-like transitions between ac-Stark-shifted Bloch bands. Such
transitions correspond to resonances described theoretically by avoided
quasienergy crossings. We show that the width of such anticrossings can be
inferred from measurements involving asymmetric pulses. We also introduce a
pulse tracking strategy for locating the particular driving amplitudes for
which resonances occur. Our numerical calculations refer to a currently
existing experimental set-up [Haller et al., PRL 104, 200403 (2010)].
