Inclusive processes from lattice QCD: problems and opportunities

A strategy to compute inclusive hadronic processes in lattice QCD is now available. The key idea is to view the inclusive decay or scattering rate as a smeared spectrum. The Euclidean time dependence of correlators obtained on the lattice can be used to approximate them. The method induces its own systematic errors in addition to the standard discretization effects and so on. It is crucial to estimate them in a rigorous manner to achieve first-principles calculations of this important new class of quantities.