Vavilov–Cherenkov Radiation when Cosmic Rays Pass through the Relic Photon Gas and when Fast Charged Particles Traverse an Optical Laser Beam
Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences,
Pyzhevskii per. 3, Moscow, 109017 Russia
Correspondence to: *e-mail: email@example.com
Received 7 December, 2015
Abstract—Using a new [9, 10] quantum theory of Vavilov–Cherenkov radiation (VCR) based on Abraham’s theory, we show that a threshold VCR effect can be excited by the relic photon gas when relativistic charged cosmic-ray particles with γ ≥ γth ≈ 1.9 × 1010 (where γ–2 = 1 – v2/c2, v is the particle speed, and c is the speed of light in a vacuum) pass through it. This is compatible with the well-known GZK cutoff [7, 8] at γ ≈ 1011. We have obtained the condition γ > γth ≈ 2.1 × 102 for the appearance of VCR when a sufficiently fast charged particle (an electron, a proton, or a nucleus) passes through intense laser radiation. This condition ensures that VCR can be observed experimentally (e.g., on the Large Hadron Collider) without invoking any additional conditions required from the currently existing estimate of γth > 8.8 × 104  based on the now universally accepted quantum theory of VCR, which follows from Minkowski’s theory (and which gives an estimate of γ > 1021 when excited by the relic photon gas).