  We investigate the two-magnon Raman scattering from an anisotropic S=1/2
triangular Heisenberg antiferromagnet Cs2CuCl4. We find that the Raman response
is very sensitive to magnon-magnon interactions and to scattering geometries, a
feature that is in remarkable contrast with the polarization-independent Raman
signal from the isotropic triangular Heisenberg antiferromagnet. Since a
spin-liquid ground state gives rise to a similar rotationally invariant Raman
response, our results on the polarization dependence of the scattering spectrum
suggest that Raman spectroscopy provides a useful probe, complementary to
neutron scattering, of the ground-state properties of Cs2CuCl4, particularly
whether the time-reversal symmetry is broken in the ground state.

Strongly Correlated Electrons