DEEP-INELASTIC NEUTRON-SCATTERING FROM FLUID PARAHYDROGEN AND ORTHOHYDROGEN

New experimental neutron scattering data from fluid and solid molecula r hydrogen at high momentum transfer are interpreted by means of a the oretical calculation able to describe the data both for parahydrogen a nd for an ortho-parahydrogen mixture over a wide momentum transfer ran ge. Our approach, valid for any diatomic molecule, reveals the occurre nce of final state effects in the scaling function and their q depende nce. It appears that at high momentum transfer the dominant final stat e effects are those coming from the intramolecular interaction.