Production of X(3872) and a photon in e+e- annihilation

If X(3872) is a weakly bound charm-meson molecule, it can be produced in e(+)e(-) annihilation by the creation of D*(0)(D) over bar*(0) from a virtual photon followed by the rescattering of the P-wave charm-meson pair into the X and a photon. A triangle singularity produces a narrow peak in the cross section for e(+)e(-) -> X gamma about 2.2 MeV above the D*(0)(D) over bar*(0) threshold. We predict the normalized cross section in the region of the peak. We show that the absorptive contribution to the cross section for e(+)e(-) -> D*(0)(D) over bar*(0) -> X gamma, which was calculated previously by Dubynskiy and Voloshin, does not give a good approximation to the peak from the triangle singularity.