Lifetime of roton in liquid helium
Blagoveshchenskii N.M., Dokukin E.B.
The temperature dependence of the lifetime and energy of the roton was investigated by the method of inelastic scattering of neutrons. It follows from the results that the elementary theory of the roton lifetime in superfluid He4 does not explain satisfactorily the Γ (Τ) dependence, and calls for invoking additional broadening mechanisms. Strong damping of the roton at the λ point was experimentally demonstrated.