M. Biyajima, Yoshimasa Takaya
Apr 1, 1971
Progress of Theoretical Physics
All the one-loop diagrams of the dual-resonance model are calculated in the proper-time formulation. The non-planar diagrams are easily calculated by diagonalization or by elimination of the twisting operator. Our methods differ from those of Princeton group. Combining the invariance properties of the proper-time equation with the above methods, we easily obtain an amplitude of one-loop diagrams with any number of twisting operators.