Short and long distance interplay in inclusive B → Xdγ decay

We analyze the short and long distance contributions to inclusive B → Xdγ decay, paying particular attention to the dependence on the Cabibbo-Kobayashi-Maskawa parameter Vtd. We discuss penguin diagrams with internal u and c quarks in the framework of the effective field theory. We also estimate the size of possible long range contributions by using vector meson dominance.