THE PROTON MATRIX ELEMENT OF THE TOPOLOGICAL CHARGE IN QUENCHED QCD

We compute on the lattice the on-shell proton matrix element of the to pological charge density in the quenched approximation. Our calculatio n makes use of a nonperturbative means of determining the multiplicati ve renormalization of the topological charge density. This work is a f irst step towards a computation of the proton spin structure function, the so-called spin content of the proton, in full QCD.