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arXiv · hep-ph/0508148

Low-Energy Neutrino Majorana Phases and Charged-Lepton Electric Dipole Moments

Andre de Gouvea·Shrihari Gopalakrishna
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Abstract

If the neutrinos are Majorana fermions, there are at least three new, potentially observable CP-odd phases that parameterize CP-invariance violating phenomena. We currently have no information regarding any of them and know that two out of the three, the so-called Majorana phases, are very hard to access experimentally. Here, we discuss the effect of Majorana phases on charged-lepton electric dipole moments (EDM), and explicitly show that neutrino Majorana phases induce EDMs even in the absence of other sources of CP-invariance violation. We also argue that while the Majorana neutrino contribution to EDMs is tiny, there is one generic ultraviolet completion to the standard model plus massive Majorana neutrinos -- the standard model plus a triplet Higgs boson -- that leads to significantly enhanced contributions which are still proportional to the low-energy neutrino Majorana phases. If this particular scenario is realized in nature, it seems possible, at least in principle, to measure the Majorana phases by precisely measuring charged-lepton EDMs.

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Andre de Gouvea, Shrihari Gopalakrishna. 2005-08-12. Low-Energy Neutrino Majorana Phases and Charged-Lepton Electric Dipole Moments. https://doi.org/10.1103/physrevd.72.093008

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