  We propose a flux representation based lattice formulation of the partition
function corresponding to the SU(2) principal chiral Lagrangian, including a
chemical potential and scalar/pseudo-scalar source terms. Lattice simulations
are then used to obtain non-perturbative properties of the theory, in
particular its mass spectrum at zero and non-zero pion density. We also sketch
a method to efficiently measure general one- and two-point functions during the
worm updates.
