Precision-Era Reassessment of Modified Quark--Lepton Complementarity: NuFIT 6.1, Phase-Convention Covariance and Lepton-Number Violation
Abstract
Quark-lepton complementarity (QLC) provides a phenomenological framework for comparing quark and lepton flavour structures. We reassess a modified QLC correlation-matrix construction using the 2026 Particle Data Group quark-mixing inputs and the NuFIT 6.1 oscillation likelihoods. The historical prediction sin2θ23=0.4235 is strongly disfavoured, with Δχ2=17.99 for normal ordering and 20.43 for inverted ordering, whereas later ordering-dependent estimates remain compatible with present preferred regions. Reconstructed ensembles of the complex correlation matrix show that the first row is comparatively stable, while about 99\% of the squared mean-texture evolution occurs in the lower two rows; roughly 72\% of the present ensemble remains closer to the tribimaximal than to the bimaximal reference texture. We further formulate the lepton sector in the symmetric Schechter-Valle parametrization. The oscillation phase appears as the invariant combination δ=ϕ13−ϕ12−ϕ23, while independent phase directions remain relevant to lepton-number-violating (LNV) amplitudes. We prove that, for unrestricted diagonal quark-lepton mismatch phases, changing from the standard PDG convention to the symmetric parametrization leaves the full ensemble of |Vc,ij| invariant: additional left phases are absorbed into the mismatch matrix and right phases only rephase columns. Consequently, the QLC magnitude texture does not constrain the independent Majorana/LNV phases. The historical S1 and S2 limits are also found to lie close to their phase-agnostic kinematic ceilings.
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BibTeX
@misc{sharma2026precisionera,
title = {{Precision-Era Reassessment of Modified Quark--Lepton Complementarity: NuFIT 6.1, Phase-Convention Covariance and Lepton-Number Violation}},
author = {Gazal Sharma and Gaurav Katoch},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2608.18812},
eprint = {2608.18812},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.18812},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Precision-Era Reassessment of Modified Quark--Lepton Complementarity: NuFIT 6.1, Phase-Convention Covariance and Lepton-Number Violation
AU - Gazal Sharma
AU - Gaurav Katoch
PY - 2026
DA - 2026/09/15
PB - arXiv
DO - 10.48550/arxiv.2608.18812
UR - https://arxiv.org/abs/2608.18812
AB - Quark-lepton complementarity (QLC) provides a phenomenological framework for comparing quark and lepton flavour structures. We reassess a modified QLC correlation-matrix construction using the 2026 Particle Data Group quark-mixing inputs and the NuFIT 6.1 oscillation likelihoods. The historical prediction sin^2θ_23=0.4235 is strongly disfavoured, with Δχ^2=17.99 for normal ordering and 20.43 for inverted ordering, whereas later ordering-dependent estimates remain compatible with present preferred regions. Reconstructed ensembles of the complex correlation matrix show that the first row is comparatively stable, while about 99\% of the squared mean-texture evolution occurs in the lower two rows; roughly 72\% of the present ensemble remains closer to the tribimaximal than to the bimaximal reference texture. We further formulate the lepton sector in the symmetric Schechter-Valle parametrization. The oscillation phase appears as the invariant combination δ=ϕ_13−ϕ_12−ϕ_23, while independent phase directions remain relevant to lepton-number-violating (LNV) amplitudes. We prove that, for unrestricted diagonal quark-lepton mismatch phases, changing from the standard PDG convention to the symmetric parametrization leaves the full ensemble of |V_c,ij| invariant: additional left phases are absorbed into the mismatch matrix and right phases only rephase columns. Consequently, the QLC magnitude texture does not constrain the independent Majorana/LNV phases. The historical S_1 and S_2 limits are also found to lie close to their phase-agnostic kinematic ceilings.
ER -