Associate production of a heavy quark and a gauge boson at ep colliders

We study the reaction e+p→e+Q+V+X, where Q stands for a c or b quark and V=γ, W or Z. At HERA only the combination Q=c, V=γ seems promising; it should allow to measure the c-quark density inside both the proton and the photon. Here, c-quarks are identified through their mounic decays. At LEP×LHC, {Mathematical expression} and {Mathematical expression} production also have sizeable rates; the first reaction might allow to measure the b content of the photon, while the second reaction can determine the strange-sea and the valence d-quark distributions in the proton, and might provide a statistically independent measurement of the WWγ vertex.