  We study the properties of light mesons in the scalar, pseudo-scalar, and
vector channels within the light-front quantization, by using the (one flavor)
Nambu--Jona-Lasinio model with vector interaction. After taking into account
the effects of chiral symmetry breaking, we derive the bound-state equation in
each channel in the large N limit (N is the number of colors), which means that
we consider the lowest q\bar{q} Fock state with the constituent quark and
antiquark. By solving the bound-state equation, we simultaneously obtain a mass
and a light-cone (LC) wavefunction of the meson. While we reproduce the
previous results for the scalar and pseudo-scalar mesons, we find that, for a
vector meson, the bound-state equations for the transverse and longitudinal
polarizations look different from each other. However, eventually after
imposing a cutoff which is invariant under the parity and boost
transformations, one finds these two are identical, giving the same mass and
the same (spin-independent) LC wavefunction. When the vector interaction
becomes larger than a critical value, the vector state forms a bound state,
whose mass decreases as the interaction becomes stronger. While the LC
wavefunction of the pseudo-scalar meson is broadly distributed in longitudinal
momentum (x) space, that of the vector meson is squeezed around x=1/2.
