Diquarks in lattice QCD

Diquarks are often invoked as QCD effective degrees of freedom to describe baryons as well as certain exotic hadrons in phenomenology. However, even though they are successful in describing many of these low lying QCD states, they and their properties have been difficult to pin down. Here we present progress in studying diquarks in a gauge-invariant setup through embedding them in a parent hadron containing a heavy spectator quark using lattice QCD calculations.