2025/12/17 by Ghosh, Gayatri
Computer Science · Physics and Astronomy · #Computational Physics and Python Applications #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Neutrino Physics Research #Particle physics theoretical and experimental studies
paper · doi:10.48550/arxiv.2512.15654
openalex publication_date 2025/12/17 · openalex created_date 2025/12/19 · openalex updated_date 2026/07/28
The origin of the baryon asymmetry of the Universe remains one of the central open problems in particle physics and cosmology. We identify a regime of hybrid resonant leptogenesis in renormalizable SO(10) grand unified theories, where a quasi-degeneracy between the scalar triplet and the heaviest right-handed neutrino, \( MT ≃ MN3, \) naturally arises from their common origin in unified scalar multiplets and leads to an enhanced interference between type-I and type-II decay amplitudes. This interference gives rise to a physical CP-violating phase, \( ϕ\rm HR = arg(μf Yν^†), \) which cannot be removed by field redefinitions and induces a resonant enhancement of the baryon asymmetry without requiring extreme Yukawa hierarchies or fine-tuned mass splittings. We show that the observed asymmetry, \( YB ≃ 8.7 × 10-11, \) can be reproduced for mass scales around \(1011 GeV\), moderate washout effects, and O(1) CP-violating phases. The mechanism leads to correlated low-energy signatures in lepton-flavour violation and electric dipole moments, providing potential experimental tests.