A resonant-level impurity Hamiltonian with finite range interactions is considered. It is shown that for repulsive interactions above a critical threshold, the model displays scale invariant properties unlike those of a Fermi liquid. The various correlation functions behave as power laws with nonuniversal exponents depending on the interactions. At the transition between the Fermi-liquid and non-Fermi-liquid regimes the resistivity behaves as A+B/ln(T${)}^2$, whereas it behaves as A+${\mathit{BT}}^{\nu }$ with ν>0 in the latter.

• Received 29 October 1992

DOI:https://doi.org/10.1103/PhysRevLett.70.3967