The gross features of the low-lying spectrum of mesons and baryons have long been described in terms of constructions featuring a minimal number of constituent quarks. QCD, the strongly coupled gauge theory of quarks and gluons should, on the face of it, exhibit a richer spectrum of states including those in which the gluonic field plays an active role. One such class of states are 'hybrid' mesons and baryons in which the required quarks are coupled to an excitation of the gluonic field. I will discuss how recent advances in the application of lattice field theory methods to the problem have made possible a developing phenomenology of gluonic excitations that describes hybrid mesons and baryons.

Argonne Physics Division Colloquium Schedule