ar X iv : 0 81 0 . 56 56 v 1 [ he p - ph ] 3 1 O ct 2 00 8 The BSW Impact Picture 30 Years After 1

Thirty years ago Bourrely-Soffer-Wu (BSW) investigated an impact picture description of p−p and p̄−p elastic scattering with success. For this anniversary, a short review of the main features of this picture will be presented with its evolution over the years. The future experiments at the LHC collider will provide decisive tests for the impact picture at high energy. In the year 1978, BSW proposed an impact parameter description of the high energy behavior of elastic p− p and p̄−p scattering [1]. A main feature was the peculiar form of the energy dependence of the pomeron, based on the results of Cheng and Wu [2, 3] derived from the high-energy behavior of quantum field theory. Later, in 1984, with the advent of p̄− p experiments, a more complete analysis was performed [4, 5]. I will present a recent update of the results which are focused on the LHC energy domain. An extension to the elastic processes π − p and K − p can be found in [6]. Moreover, we have also shown that under certain assumptions γ − p and γ − γ total cross sections can be predicted [7]. In the impact-picture representation, the spin-independent scattering amplitude2, for pp and p̄p elastic scattering, reads as