We propose an exact solution of a model describing a low energy behavior of
cold isospin S=3/2 fermionic atoms on a one-dimensional optical lattice.
Depending on the band filling the effective field theory has a form of a
deformed Gross-Neveu model with either O(7)×Z2 (half filling)
or U(1)×O(5)×Z2 symmetry.Comment: 4 pages, no figures, replaced with the final version to appear in PR