Search for non-standard production of single top quarks at D0

The large mass of the top quark, close to the electroweak symmetry-breaking scale, makes it a good candidate for probing physics beyond the Standard Model. Single top quarks may be produced in the decay of a new heavy gauge boson W' and we present limits on the production cross section and the mass of such a W' assuming standard model like couplings. We also search for single top productions through flavor changing neutral currents involving gluon, Z boson, or photon exchange.