The new hadron spectroscopy.

In the last ten years exotic hadron resonances have been discovered in high energy collider experiments. Indeed the internal structure of these hadrons, conventionally called XYZ, cannot be explained in terms of standard mesons or baryons, made up by a quark and an antiquark or by three quarks. In this PhD thesis we show how the decay and, above all, the production mechanisms of the XYZ could be useful in testing some theoretical hypotheses against experimental data. Moreover we propose to perform some indirect searches in order to discover if the experimental picture as we know it nowadays is complete or otherwise