  High-mass microquasars are binary systems consisting of a massive star and an
accreting compact object from which relativistic jets are launched. There is
considerable observational evidence that winds of massive stars are clumpy.
Individual clumps may interact with the jets in high-mass microquasars to
produce outbursts of high-energy emission. Gamma-ray flares have been detected
in some high-mass X-ray binaries, such as Cygnus X-1, and probably in LS 5039
and LS I+61 303. We predict the high-energy emission produced by the
interaction between a jet and a clump of the stellar wind in a high-mass
microquasar. Assuming a hydrodynamic scenario for the jet-clump interaction, we
calculate the spectral energy distributions produced by the dominant
non-thermal processes: relativistic bremsstrahlung, synchrotron and inverse
Compton radiation, for leptons, and for hadrons, proton-proton collisions.
Significant levels of emission in X-rays (synchrotron), high-energy gamma rays
(inverse Compton), and very high-energy gamma rays (from the decay of neutral
pions) are predicted, with luminosities in the different domains in the range ~
10^{32}-10^{35} erg/s. The spectral energy distributions vary strongly
depending on the specific conditions. Jet-clump interactions may be detectable
at high and very high energies, and provide an explanation for the fast TeV
variability found in some high-mass X-ray binary systems.
  Our model can help to infer information about the properties of jets and
clumpy winds by means of high-sensitivity gamma-ray astronomy.
