Resolving the octant of theta_{23} via radiative mu-tau symmetry breaking

Abstract

We point out that the observed neutrino mixing pattern at low energies is very likely to originate from the 3 times 3 lepton flavor mixing matrix U which possesses the exact mu-tau permutation symmetry |U_{mu i}| = |U_{tau i}| (for i=1,2,3) at a superhigh energy scale Lambda_{mu tau} \sim 10^{14} GeV. The deviation of theta_{23} from 45^\circ and that of delta from 270^\circ in the standard parametrization of U are therefore a natural consequence of small mu-tau symmetry breaking via the renormalization-group equations (RGEs) running from Lambda_{mu tau} down to the electroweak scale Lambda_{EW} \sim 10^2 GeV. In fitting current experimental data we find that the RGE-corrected value of theta_{23} is uniquely correlated with the neutrino mass ordering: theta_{23} \simeq 42.4^\circ reported by Capozzi et al (or theta_{23} \simeq 48.9^\circ reported by Forero et al) at Lambda_{EW} can arise from theta_{23} = 45^\circ at Lambda_{mu tau} in the minimal supersymmetric standard model if the neutrino mass ordering is inverted (or normal). Accordingly, the preliminary best-fit results of delta at Lambda_{EW} can also evolve from delta = 270^\circ at Lambda_{mu tau} no matter whether the massive neutrinos are Dirac or Majorana particles.

12 pages, 3 tables, 2 figures, minor changes, references updated, accepted for publication in Phys. Rev. D

References in corpus (12)

• Observation of electron-antineutrino disappearance at Daya Bay
• Global fit to three neutrino mixing: critical look at present precision
• Neutrino oscillations refitted
• S_4 Flavored CP Symmetry for Neutrinos
• Lepton Mixing Parameters from $\Delta (48)$ Family Symmetry and Generalised CP
• Implications of Leptonic Unitarity Violation at Neutrino Telescopes
• Octahedral Symmetry with Geometrical Breaking: New Prediction for Neutrino Mixing Angle theta_{13} and CP Violation
• Generalised CP and $\Delta (96)$ Family Symmetry
• Large U_{e3} and Tri-bimaximal Mixing
• A partial $\mu$-$\tau$ symmetry and its prediction for leptonic CP violation
• Tetra-maximal Neutrino Mixing and Its Implications on Neutrino Oscillations and Collider Signatures
• Radiative corrections to the leptonic Dirac CP-violating phase

Cited by in corpus (3)

• The minimal seesaw and leptogenesis models
• On the four-zero texture of quark mass matrices and its stability
• The $\mu$-$\tau$ reflection symmetry of Majorana neutrinos