Propagating microscopic temperature fluctuations in a dense helium fluid at 13.3 K

A neutron-scattering experiment on dense semiclassical helium at 13.3 K and 203 bars reveals that the dynamic structure factor S(k,ω) has a clearly visible side peak at the frequency ωT(k) for wave numbers 3≤k≤11 nm-1. ωT is the oscillation frequency of propagating temperature fluctuations, an effect not seen in dense classical fluids