A discussion of the dispersion curve of energy excitations in liquid 4He

An investigation of the dispersion of excitations in a quantum liquid, superfluid 4He, is carried out. An attempt is made to systematize the published experimental data that indicate a substantially different nature of excitations with wave vectors corresponding to different parts of the dispersion curve of liquid 4He. Neutron spectroscopy data are analyzed in relation to a certain physical hypothesis concerning the formation of such a spectrum, and it is found that the majority of the known experimental facts can be explained in framework of that hypothesis. Particular attention is paid to a comparison of the experimental data obtained on the DIN-2PI time-of-flight spectrometer (at the IBR-2 Reactor, Dubna) with the results obtained at foreign research centers.