How to Measure the QQ Potential in a Light-Front Calculation

A scheme is developed which shows how one would, given a light-front Hamiltonian for QCD, extract the QQ potential, i.e. the quantity which corresponds to the potential between two infinitely heavy quarks in a rest frame, from a light-front calculation. The resulting potential will in general depend on the direction along which the infinitely heavy sources are separated and thus provides a direct probe of violations of rotational invariance in a physical observable. Furthermore, easy comparison to data from cc and bb spectroscopy and to lattice data is possible. The scheme may thus be very helpful in constructing a light-front Hamiltonian through an iterative procedure.