A new singularity in the dispersion of impurity excitation in superfluid helium
Esel'son B.N. , Slyusarev V.A., Sobolev V.I., Strzhemechnyi M.A.
It is shown that the impurity branch of the energy spectrum of the elementary excitations of He3-He4 solutions has an end point at which decay into a roton and an He3 quasiparticle with small momentum takes place. The parameters of this spectrum are obtained.