On the spin evolution of neutron stars in pre-low-mass X-ray binaries

We present a simple model for the evolutionary states of neutron stars in pre-low-mass X-ray binaries during the main sequence stage of donor stars. It is shown that for typical parameters some of the neutron stars in these systems can not accrete matter from winds of their companions in a stable way. Accretors are found if neutron stars have magnetic fields about 10 13 G and higher and/or in close systems with orbital periods about a