CP violations in predictive neutrino mass structures

Chao-Qiang Geng; Da Huang; Lu-Hsing Tsai

doi:10.1140/epjc/s10052-015-3779-9

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2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2015) 75: 557
https://doi.org/10.1140/epjc/s10052-015-3779-9

Regular Article - Theoretical Physics

CP violations in predictive neutrino mass structures

Chao-Qiang Geng¹^,2^,3^*, Da Huang² and Lu-Hsing Tsai²

¹ Chongqing University of Posts and Telecommunications, Chongqing, 400065, China
² Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
³ Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan

^* e-mail: geng@phys.nthu.edu.tw

Received: 13 September 2015
Accepted: 5 November 2015
Published online: 26 November 2015

Abstract

We study the CP-violation effects from two types of neutrino mass matrices with (i) $(M_\nu )_{ee}=0$ , and (ii) $(M_\nu )_{ee}=(M_\nu )_{e\mu }=0$ , which can be realized by the high-dimensional lepton number violating operators $\bar{\ell }_R^c\gamma ^\mu L_L (D_\mu \Phi )\Phi ^2$ and $\bar{\ell }_R^c l_R (D_\mu {\Phi })^2\Phi ^2$ , respectively. In (i), the neutrino mass spectrum is in the normal ordering with the lightest neutrino mass within the range $0.002\,\mathrm{eV}\lesssim m_0\lesssim 0.007\,\mathrm{eV}$ . Furthermore, for a given value of $$m_0$$ , there are two solutions for the two Majorana phases $\alpha _{21}$ and $\alpha _{31}$ , whereas the Dirac phase $\delta$ is arbitrary. For (ii), the parameters of $$m_0$$ , $\delta$ , $\alpha _{21}$ , and $\alpha _{31}$ can be completely determined. We calculate the CP-violating asymmetries in neutrino–antineutrino oscillations for both mass textures of (i) and (ii), which are closely related to the CP-violating Majorana phases.