1. Cf.,e.g.,M. Gell-Mann andF. E. Low:Phys. Rev.,95, 1300 (1954).
2. I. F. Ginzburg, A. V. Efremov andV. G. Serbo:Yad. Fiz.,9, 451 (1969);I. F. Ginzburg andV. G. Serbo:Yad. Fiz.,9, 868 (1969).
3. A. V. Efremov, I. F. Ginzburg andV. G. Serbo: JINR E2-4572 (1969);
4. V. M. Budnev, I. F. Ginzburg andV. G. Serbo:Sov. Journ. Theor. Math. Phys.,6, 55 (1971);
5. A. V. Efremov andI. F. Ginzburg:Phys. Lett.,36 B, 371 (1971). Here the calculations were made at $$\varepsilon _{\dot \iota } = 0$$ andg s =0. However, their extension to the case $$\varepsilon _{\dot \iota } \ne 0$$ andg s ≠0 is easy.