Propagation of relativistic charged particles in ultracold atomic gases with Bose-Einstein condensates
Yu.V. Slyusarenko and A.G. Sotnikov
Akhiezer Institute for Theoretical Physics NSC KIPT, 1 Akademichna Str., 61108 Kharkiv, Ukraine,
E–mail: slusarenko@kipt.kharkov.ua
We consider some effects arising at charged particle propagation in Bose-Einstein condensate (BEC) of alkali metals atomic gasses. The charged particle energy change in Vavilov-Cherenkov phenomenon in a gas with condensate is studied. It is shown that to gain Cherenkov ef- fect in the investigated system the particles must have high (relativistic) velocity since in rarified gasses refractive index is close to unity in res- onant frequencies range. The particles energy change while propagating through BEC are defined via gas permittivity expressions. It is shown that the particle under certain conditions is capable of both loosing the energy and acceleration by the ultracold gas. The basic case of rela- tivistic particle acceleration by a rarified gas of atoms at temperatures close to absolute zero is discussed. The possibilities of atomic spectral characteristics definition with help of Cherenkov effect in gas with BEC are studied. It is shown that by means of particle velocity variation and thus, the definition of gas refractive index maximum, we can determine natural atomic spectral level width if we know additional spectral or microscopic characteristics of atoms.
1
