This paper studies with the help of perturbation theories the asymptotic properties of a ladder in the s channel as the momentum transfer t→∞ and some external masses M2→t1/2. The knowledge of such a property is essential to the calculation of the asymptotic property (as the momentum transfer t→∞) of a diagram which connects a ladder (in the s channel) and an ordinary pole in parallel.This paper studies also the absorptive part in the t channel of the above diagram, namely one which connects a ladder in the s channel and an ordinary pole in parallel. It proves that if the partial waves in the s channel possesses a Regge cut, the starting point of such a cut must lie to the left of the position given by current theories.
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