Iterative determination of analytic continuation and its application to the pp forward amplitude

A report is made on a new attempt to determine analytic continuation of scattering amplitudes, which consists of evaluating iteratively on a computer the usual dispersion relation and its inverted one. Its application to the pp forward amplitude shows that this method is practical and powerful. Its imaginary part is shown to have a large dip just above the p p threshold, which makes its high-energy real part nearly twice that determined experimentally ignoring spin-flip.