An inelastic X-ray scattering experiment has been performed in liquid
aluminum with the purpose of studying the collective excitations at wavevectors
below the first sharp diffraction peak. The high instrumental resolution (up to
1.5 meV) allows an accurate investigation of the dynamical processes in this
liquid metal on the basis of a generalized hydrodynamics framework. The
outcoming results confirm the presence of a viscosity relaxation scenario ruled
by a two timescale mechanism, as recently found in liquid lithium.Comment: 8 pages, 7 figure