In this talk I reviewed the present status and recent progress on lightmeson scattering analyses, by means of dispersive or analytic methods. The application these model independent techniques have settled controversy about existence parameters long debated light meson resonances. will thus discuss here state art changes our knowledge spectroscopy scalar mesons when observed from such processes.

We investigate the nucleon-nucleon interaction by using the meson exchange model and the two body Dirac equations of constraint dynamics. This approach to the two body problem has been successfully tested for QED and QCD relativistic bound states. An important question we wish to address is whether or not the two body nucleon-nucleon scattering problem can be reasonably described in this approa...

The factorisation of the hard amplitude for exclusive meson production in deep inelastic scattering is considered in the framework of a simple model. It is demonstrated explicitly how gauge invariance ensures the cancellation of non-factorising contributions.

I will discuss recent results of the NPLQCD Collaboration regarding the calculation of hadronic interactions with lattice QCD. A particular emphasis will be spent on pi-pi scattering and other meson interactions.

The N * (1440), or Roper resonance, plays an important role in nucleon and nuclear dynamics as an intermediate state. The excitation of a Roper may mediate pion electro-and photoproduction processes 1 , pion and double pion production in N N reactions 2,3 , heavy ion collisions 4 , etc. In this context, the knowledge of the N N → N N * (1440) interaction and the πN N * (1440) and σN N * (1440) ...