  We predict concurrent selforganisation and cooling of multispecies ensembles
of laser-illuminated polarisable particles within a high-Q cavity mode.
Resonant collective scattering of laser light into the cavity creates optical
potentials which above a threshold pump power transforms a homogeneous particle
distribution to a crystalline order for all constituents. Adding extra
particles of any mass and temperature always lowers the pump power required for
selfordering and allows to concurrently trap atoms, for which high phase-space
densities are readily available, in combination with many other kind of atoms,
molecules or even polarisable nanoparticles. Collective scattering leads to
energy exchange between the different species without direct collisional
interactions. We analytically calculate the threshold condition, energy fluxes
and the resulting equilibrium phase-space distributions and show that
cavity-mediated energy transfer enhances cooling of heavy particles by adding
light particles forming a cold reservoir. Extensive numerical many-body
simulations support the results of our kinetic analytic model.

Quantum Physics;Quantum Gases;Atomic Physics