We suggest a new mechanism for the formation of true muonium (T\!M), the QED (^+ ^-) bound state, due to the Coulomb interaction of muons from ^+ ^- pairs generated in the Drell-Yan reaction of protons off nuclei of a thin foil target. The T\!M atoms produced in the ³S₁ long-lived triplet state (oT\!M) could escape from the foil to vacuum followed by their decay into e^+e^- pairs. Observation of e^+e^- events with a displaced vertex, and an invariant mass and decay time consistent with the mass and lifetime of the oT\!M is used as a signature of the discovery of T\!M. We present estimates of the T\!M yield and briefly discuss an experiment which could lead to such a discovery.
Gninenko et al. (Mon,) studied this question.