The spin-charge-separated Luttinger liquid in arbitrary spatial dimensions and in the applied external magnetic field is investigated within an exactly solvable model of correlated fermions. Exact eigenstates, eigenvalues, and correlation functions of this system are determined and its single-pseudoparticle properties are discussed. It is shown that strongly correlated fermions of spin one-half and charge one, which are described by the present model, can be mapped onto a system of noninteracting fermionlike pseudoparticles possessing continuous charge and spin. The charge and the spin of these pseudoparticles acquire arbitrary values between 0 and
e and 0 and $\ensuremath{\Elzxh}/2$, respectively, when the magnetic field is varied. These pseudoparticles represent quanta of exact elementary excitations in this system.
We study in this paper the general properties of a many body system of fermions in arbitrary dimensions assuming that the {\em momentum} of individual fermions are good quantum numbers of the system. We call these systems
k-Fermi liquids. We show how Fermi liquid, Luttinger liquid (or Fermi liquid with exclusion statistics) and spin-charge separation arises from this framework. Two exactly solvable
k-Fermi liquid models with spin-charge separation are discussed as examples.