  The mechanism that can be responsible for the bimodal luminosity distribution
of super-Eddington X-ray pulsars in binary systems is pointed out. The
transition from the high to low state of these objects is explained by
accretion flow spherization due to the radiation pressure at certain (high)
accretion rates. The transition between the states can be associated with a
gradual change in the accretion rate. The complex behavior of the recently
discovered ultraluminous X-ray pulsars M 82 X-2, NGC 5907 ULX-1, and NGC 7793
P13 is explained by the proposed mechanism. The proposed model also naturally
explains the measured spinup of the neutron star in these pulsars, which is
slower than the expected one by several times.
