Final State Effects in the high q response of He-3-He-4 mixtures

A modified Gersch-Rodriguez formalism describing the lending Final State Ef fects in the high momentum transfer response of low concentration He-3-He-4 mixtures is presented and discussed. The leading corrections to the Impuls e Approximation are expressed in terms of the interatomic potentials and th e semidiagonal two-body density matrices of both the mixture and its boson- boson approximation, in which the He-3 atoms are replaced by bosons of the same mass and at the same partial density. Numerical calculations of the Fi nal State Effects functions of He-3 and He-4 are finally (C) 2000 Elsevier Science B.V. All rights reserved.