High-Energy Elastic Hadron Scattering: Studies on the Direct and Inverse Problems

Abstract

Experimental data on pp collisions from the CERN-LHC obtained in 2012 and 2013, provided important checks and developments of the Standard Model, including its strong (hadronic) sector. However, despite the novel experimental information and the successes of QCD as the theory of the strong interactions, the elastic hadron scattering still constitutes a great challenge for the QCD. In fact, as a soft scattering state (small momentum transfer / large distances) it is not formally accessed by perturbative approaches and currently a non perturbative formalism, from the first principles of QCD and independent of model assumptions is still lacking. In the phenomenological context, models are based on different physical pictures and depend on a rather large number of free parameters. Moreover, representative model predictions for the LHC energy region have shown no agreement with the new data on pp elastic collisions. It is expected that further data will provide important information for the necessary development on the soft strong interaction sector of QCD.In this context (experimental, theoretical and phenomenological), we propose a novel simultaneous investigation on both direct and inverse problems related to the pp elastic scattering. Based on recent empirical and theoretical results the main goals of the project are: (1) extraction of empirical information (laws/properties) on the physical quantities characterizing the elastic scattering as a function of both energy and transferred momentum in the collision; (2) to obtain the corresponding characteristics (analytical parametrizations) in the impact parameter and eikonal representations, specially in the momentum transfer space (the inverse problem); (3) to use this information to look for conections with non perturbative QCD results (functional methods, solutions of the Schwinger-Dyson equations and Lattice QCD); (4) by means of a feedback processes related to items (1) to (3), development of a non perturbative (QCD) formalism, with empirical basis and able to present satisfactory descriptions of the pp elastic scattering data (the direct problem), testing also extensions to single and double diffractive processes and other reactions (mesons-proton).