@article{Loktev_Tomchenko_2022, title={On the Nature of a Narrow Roton Absorption Line in the Spectrum of a Disk-shaped SHF Resonator}, volume={56}, url={https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2022154}, DOI={10.15407/ujpe56.1.49}, abstractNote={<p>We calculate the probability of the creation of a circular phonon (c-phonon) in He II by a c-photon of the resonator. It is shown that this probability has sharp maxima at frequencies, where the effective group velocity of the c-phonon is equal to zero; the density of states of c-phonons strongly grows at such frequencies. For He II, these frequencies correspond to a roton and a maxon. From the<br>probability of the c-roton creation, we calculate the roton line width which is found to approximately agree with the experimental one. We conclude that the roton line observed in the super-high-frequency (SHF) absorption spectrum of helium is related to the creation of c-rotons. A possible interpretation of the Stark effect observed for the roton line is also proposed.</p>}, number={1}, journal={Ukrainian Journal of Physics}, author={Loktev, V.M. and Tomchenko, M.D.}, year={2022}, month={Feb.}, pages={49} }