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4. This was independently noted byW. S. Hellman, J. Rosen andP. Roman: preprint. We are indebted to these authors for communicating their results. See however, eq. (47) and subsequent discussion.
5. For this reason we do not concern ourselves with thep 2>0,p 0<0 part of the socalled «unreasonable mass spectrum». In our view it is not unreasonable at all, and is already being utilized in any standard field-theoretical description of charged particles.