  We discuss the renormalization induced by interactions of a two-dimensional
truncated Fermi surface (FS) model.Using a field theoretical renormalization
group method we calculate the critical renormalized physical chemical
potential. We show that it either vanishes or approaches a non-zero value. We
argue that the vanishing of the chemical potential is indicative of a further
truncation of the FS we started with and might well represent an insulating
spin liquid phase.
