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Minimal A4 type-II seesaw realization of testable neutrino mass sum rules

Salvador Centelles Chuliá1,* and Ranjeet Kumar2,3,†

  • *Contact author: salcen@ific.uv.es
  • †Contact author: kumarranjeet.drk@gmail.com
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Phys. Rev. D 113, 055023 – Published 13 March, 2026

DOI: https://doi.org/10.1103/ndvc-1vpl

Abstract

We propose a flavor model based on an A4 symmetry combined with a type-II seesaw mechanism for neutrino mass generation. The resulting neutrino mass matrix obeys a sum rule that, together with the measured mass-squared differences, fully determines the absolute neutrino mass spectrum. The constrained flavor structure yields correlated predictions for lepton mixing parameters, leads to inverted ordering after imposing mixing constraints, restricts the Majorana phases and implies a neutrinoless double beta decay rate close to its maximal value for inverted ordering. In the charged lepton sector an approximate triality symmetry arises in the seesaw limit, suppressing muon flavor-violating processes and allowing only specific τ decay channels. The model provides a tightly constrained and experimentally testable framework linking neutrino masses, lepton mixing, and lepton-number-violating observables.

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Phys. Rev. D 113, 055023– Published 13 March, 2026
  • Received 1 January 2026
  • Accepted 26 February 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.

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