Symanzik, K.; Derivation of Dispersion Relations for Forward Scattering
Phys. Rev. 105 (1957) 743;
SEATTLE-56 (1956);

Abstracts
The dispersion relation for forward meson-nucleon scattering is derived in the simplified case of scalar neutral particles. Use is made of the local property of the nucleon field and of certain features of the mass spectrum. In addition, it is assumed that the only singularities of certain matrix elements of the nucleon field commutator are derivatives of finite order of functions on the light cone. Under some further assumptions of existence, the dispersion
relations for the derivatives of the scattering amplitude with respect angle at zero angle can be derived.

Related references See also M. L. Goldberger, Phys. Rev. 99 (1955) 979;
G. F. Chew, Encyclopedia of Physics, Springer-Verlag, Berlin (1958);
Anderson, Davidon, Kruse, Phys. Rev. 100 (1955) 339;
M. L. Goldberger, Phys. Rev. 99 (1955) 979;
R. Oehme, Phys. Rev. 100 (1955) 1503;
R. Oehme, Phys. Rev. 102 (1956) 1174;
N. N. Bogolyubov, B. V. Medvedev, and M. K. Polivanov, Report at the Seattle conf. (1956);
Lehmann, Symanzik, and Zimmermann, Nuovo Cim. 1 (1955) 205;
F. E. Low, Phys. Rev. 97 (1955) 1392;
K. Nishijima, Progr. of Theor. Phys. 10 (1953) 549;
K. Nishijima, Progr. of Theor. Phys. 12 (1954) 279;
K. Nishijima, Progr. of Theor. Phys. 13 (1955) 305;
E. C. Titchmarsch, Theory of Fourier Integrals, Oxford University Press, Oxford (1937) 11;
H. Lehmann, Nuovo Cim. 11 (1954) 342;
M. Gell-Mann, M. L. Goldberger, and W. E. Thirring, Phys. Rev. 95 (1954) 1612;
M. L. Goldberger, H.Miyazawa, and R. Oehme, Phys. Rev. 99 (1955) 986;

Record comments
Derivation of dispersion relations in field theory for pion nucleon forward scattering amplitude.