We study quantum integrable systems of interacting particles from the
point of view proposed by A. Gorsky and N. Nekrasov. We obtain the Sut
herland system by a Hamiltonian reduction of an integrable system on t
he cotangent bundles to an affine su(N) algebra and show that it coinc
ides with the Yang-Mills theory on a cylinder. We point out that there
exists a tower of 2d quantum,field theories. The top of this tower is
the gauged G/G WZW model on a cylinder with an inserted Wilson line i
n an appropriate representation, which in our approach corresponds to
Ruijsenaars' relativistic Calogero model. Its degeneration yields the
2d Yang-Mills theory, whose small radius limit is the Calogero model i
tself. We make some comments about the spectra and eigenstates of the
models, which one can get from their equivalence with the field theori
es. Also we point out some possibilities of elliptic deformations of t
hese constructions.