Hadron Spectrum from Lattice QCD

In order to claim that we understand strong interactions quantitatively, we should be able to derive key properties of hadrons, such as their mass, “ab initio” from the interaction of quarks and gluons. In particular the phenomenon of “dimensional transmutation”, i.e. of having a massive proton even with exactly massless quarks and gluons, is a distinctive property of QCD. In this talk I summarize recent e orts, in the context of the Budapest-Marseille-Wuppertal collaboration, to compute the masses of the avor non-singlet mesons and of the light baryon octet and decuplet in the isospin limit of QCD on the lattice, with fully controlled systematics.