The Cherenkov effect A charged particle traveling in a dielectric medium with n>1 radiates Cherenkov radiation if its velocity is larger than the phase velocity of light v>c/n or Î² > 1/n (threshold) The emission is due to an asymmetric polarization of the medium in front and at the rear of the particle, giving rise to a varying electric dipole momentum.
cyclo-. 1. Combining forms relating to a circle or cycle; or denoting an association with the ciliary body. 2. In chemistry, a combining form indicating a continuous molecule, without end, or the formation of such a structure between two parts of a molecule.
HCO is more commonly written as R-CHO, which is an aldehyde. An aldehyde is an organic compound containing a terminal carbonyl group. This functional group, which consists of a carbon atom bonded to a hydrogen atom and double-bonded to an oxygen atom (chemical formula O=CH-), is called the aldehyde group. The aldehyde group is also called the formyl or methanoyl group. See the link below for more information. Hope this helps!!!