Interplay of Seesaw Dominance Effects on 0νββ & Muon

Abstract

The Left-right Symmetric Model (LRSM) extends the Standard Model by including right-handed interactions, offering a framework for neutrino mass generation. The effective mass of the electron neutrino (m eff ) in this model depends on the vacuum expectation value (vev) of the right-handed Higgs triplet (vR) and Majorana phases (α and β). This connects neutrinoless double beta decay (0νββ) to high-energy scales. The LRSM incorporates Seesaw type-I and type-II mechanisms, producing a hybrid mass term for light neutrinos, with different dominance patterns shaping the neutrino spectrum. We study these dominance patterns (2 n , n = 3 for three generations) and compare theoretical results for 0νββ decay with experimental bounds from KamLAND-Zen and GERDA. Furthermore, this Seesaw interplay is evident in the muon’s anomalous magnetic moment (muon g − 2), where type-I and type-II contributions affect the observed discrepancy. These studies provide insights into Seesaw mechanisms and new physics beyond the Standard Model.