Neutrino Helicity Reversal and Fundamental Symmetries
A rather elusive helicity reversal occurs in a gedanken experiment in which a massive left-handed Dirac neutrino, traveling at a velocity u < c, is overtaken on a highway by a speeding vehicle (traveling at velocity v with u < v < c). Namely, after passing the neutrino, looking back, one would see a right-handed neutrino (which has never been observed in nature). The Lorentz-invariant mass of the right-handed neutrino is still the same as before the passing. The gedanken experiment thus implies the existence of right-handed, light neutrinos, which are not completely sterile. Furthermore, overtaking a bunch of massive right-handed Dirac neutrinos leads to gradual de-sterilization. We discuss the helicity reversal and the concomitant sterilization and de-sterilization mechanisms by way of an illustrative example calculation, with a special emphasis on massive Dirac and Majorana neutrinos. We contrast the formalism with a modified Dirac neutrino described by a Dirac equation with a pseudoscalar mass term proportional to the fifth current.
U. D. Jentschura and B. J. Wundt, "Neutrino Helicity Reversal and Fundamental Symmetries," Journal of Physics G: Nuclear and Particle Physics, vol. 41, no. 7, IOP Publishing, Jul 2014.
The definitive version is available at https://doi.org/10.1088/0954-3899/41/7/075201
Keywords and Phrases
Fundamental Symmetries; Helicity Reversal; Majorana Neutrino; Neutrino Physics; Spinor Lorentz Transformation
International Standard Serial Number (ISSN)
Article - Journal
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01 Jul 2014