Spontaneous <i>μ</i>-<i>τ</i> Reflection Symmetry Breaking in Neutrino Phenomenology

• Main Authors: Guo-Yuan Huang, Zhi-Zhong Xing, Jing-Yu Zhu
• Format: Article
• Language: English
• Published: MDPI AG 2018-12-01
• Series: Universe
• Subjects: lepton flavor mixing; <i>μ-τ</i> reflection symmetry; renormalization group equations
• Online Access: https://www.mdpi.com/2218-1997/4/12/141

The latest global analysis of neutrino oscillation data indicates that the normal neutrino mass ordering is favored over the inverted one at the <inline-formula> <math display="inline"> <semantics> <mrow> <mn>3</mn> <mi>&#963;</mi> </mrow> </semantics> </math> </inline-formula> level. The best-fit values of the largest neutrino mixing angle <inline-formula> <math display="inline"> <semantics> <msubsup> <mi>&#952;</mi> <mn>23</mn> <mrow></mrow> </msubsup> </semantics> </math> </inline-formula> and the Dirac CP-violating phase <inline-formula> <math display="inline"> <semantics> <mi>&#948;</mi> </semantics> </math> </inline-formula> are located in the higher octant and the third quadrant, respectively. We show that these experimental trends can be naturally explained by the <inline-formula> <math display="inline"> <semantics> <mi>&#956;</mi> </semantics> </math> </inline-formula>-<inline-formula> <math display="inline"> <semantics> <mi>&#964;</mi> </semantics> </math> </inline-formula> reflection symmetry breaking, triggered by the one-loop renormalization-group equations (RGEs) running from a superhigh energy scale down to the electroweak scale in the framework of the minimal supersymmetric standard model (MSSM). The complete parameter space is numerically explored for both the Majorana and Dirac cases, by allowing the smallest neutrino mass <inline-formula> <math display="inline"> <semantics> <msubsup> <mi>m</mi> <mn>1</mn> <mrow></mrow> </msubsup> </semantics> </math> </inline-formula> and the MSSM parameter <inline-formula> <math display="inline"> <semantics> <mrow> <mo form="prefix">tan</mo> <mi>&#946;</mi> </mrow> </semantics> </math> </inline-formula> to vary within their reasonable ranges.