Comment on “Spin light of neutrino in matter: a new type of electromagnetic radiation”

We show that a criticism made in hep-ph/0610294 against our paper Mod. Phys. Lett. A21, 1769 (2006) has no ground. We confirm that all results of investigations of the socalled “spin light of neutrino (SLν)” are incorrect because of the medium influence on photon dispersion. With taking account of this influence, both the SLν radiation rate and the total power are zero for neutrinos in all real astrophysical conditions. In an extended series of papers [1–11], there was proposed and investigated in detail the socalled “spin light of neutrino” (SLν), the process of the radiative neutrino transition νL → νRγ, caused by the additional energy W acquired in medium by the ultra-relativistic left-handed neutrino [12]. In their analysis the authors neglected the medium influence on the photon dispersion. It looked unnatural, because the neutrino dispersion was defined by the weak interaction while the photon dispersion was defined by the electromagnetic interaction. In the paper [13] we evaluated the effective mass acquired by a photon in the astrophysical conditions used by those authors, and we have shown qualitatively that consideration of the radiative neutrino transition νL → νRγ without taking account of the photon dispersion in medium should be incorrect. In a short reply [14], the authors wrote that our analysis was wrong because “the momentum conservation law has not been accounted for”. It was declared instead of performing an accurate application of this conservation law to the process. As we have shown further in the papers [15, 16], just the energy-momentum conservation law with the photon effective mass taken into account, has led to the threshold value for the initial neutrino energy: E > E0 ≃ mγ 2W , (1) wheremγ is the effective mass of the photon (plasmon) in medium. Evaluation of these threshold energies for different astrophysical situations shows that the value E0 is always greater in orders of magnitude than the typical neutrino energy. Thus, the photon dispersion leaves no room for “spin light of neutrino”, except for a pure theoretical possibility when an ultra-high energy ∗ e-mail: [email protected] † e-mail: [email protected]