Deuteron production in e+e--annihilation

We argue that in e+e--annihilation (including υ-decay) deuteron production should be given by the overlap of the deuteron wave function with the wave function of a pn-pair. The production rate depends sensitively upon the size of the production region. Taking into account the strong correlation between protons and neutrons, experimental results for υ-decay are consistent with the size expected in the Lund string fragmentation model. A prediction is given for the deuteron production in Z-decay