New quantum theory of the Vavilov-Cherenkov radiation and its analogues

Abstract

The general theory of non-bremsstrahlung radiation by non-equilibrium medium is proposed on the base of the new (PRL, 2004; JETP, 2004) quantum theory of Vavilov-Cherenkov radiation (VCR), where Abraham's form for the true photon momentum in the medium is used (only which allows the introduction in the energy-momentum balance equations of the effective real photon mass in the medium). This gives the possibility to consider the ejection of VCR quantum directly by medium, as complies with known assumptions of the microscopic mechanism of VCR (I.E. Tamm, 1939 and etc.). On the base of the Abraham theory, it is stated the new value of threshold velocity Vth=c/n*(n) of the charged particle, when only for V>Vth the emission by medium of the VCR or its analogues is take place for n>1 and also for n<1 (c is light velocity in vacuum, n is the refraction index of isotropic medium in equilibrium state). It allows explaining of the observed "subthreshold" VCR effects and its analogues. It is show that for n<1, value n*>1 in the expression for Vth, that allows VCR mechanism realization when emitting transversal electromagnetic waves in plasma and also while emitting by a nuclear medium interacting with sufficiently fast K+ and K0 mesons. Propose the possibility for using of the new VCR theory in relation with super radiation in Bose-Einstein condensates and with the Compton effect in medium for n<1 and n>1. Near the same consideration on the base of the new VCR quantum theory is proposed for the modification of the Landau superfluid threshold velocity theory.