Impact of dim-6 $\nu$SMEFT operators on low-scale leptogenesis

Abstract

We investigate the impact of higher-dimensional operators on low-scale leptogenesis (LG) via oscillations of right-handed neutrinos within the neutrino-extended Standard Model Effective Field Theory ($\nu$SMEFT) and discuss the connection to neutrinoless double beta decay ($0\nu \beta \beta$). Focusing on a dimension-six, lepton number conserving operator, we explore how new interactions can significantly alter the production and equilibration dynamics of right-handed neutrinos. We derive the relevant quantum kinetic equations incorporating both renormalizable and non-renormalizable interactions and perform a comprehensive numerical analysis for benchmark scenarios in both the oscillatory and overdamped regimes. Our results reveal that even in the absence of explicit lepton number violation by the operator, it can enhance or suppress the baryon asymmetry of the universe (BAU) by several orders of magnitude, depending on the EFT scale. We further connect these effects to predictions for $0\nu \beta \beta$ decay, demonstrating that the same operator can lead to enhanced decay rates, potentially within reach of the next generation of experiments. Our findings indicate that the observation of $0\nu \beta \beta$ could rule out a large part of the parameter space for successful low-scale LG within the $\nu$SMEFT, implying low RHN masses and low reheating temperatures.

49 pages, 17 figures, 5 tables, matches the published version

References in corpus (24)

• The fate of hints: updated global analysis of three-flavor neutrino oscillations
• The Sphaleron Rate in the Minimal Standard Model
• NuFit-6.0: Updated global analysis of three-flavor neutrino oscillations
• Extending the Standard Model Effective Field Theory with the Complete Set of Dimension-7 Operators
• The nuMSM, leptonic asymmetries, and properties of singlet fermions
• Heavy Majorana Neutrinos in the Effective Lagrangian Description: Application to Hadron Colliders
• A Survey of Lepton Number Violation Via Effective Operators
• Thermal production of relativistic Majorana neutrinos: Strong enhancement by multiple soft scattering
• Neutrinoless double beta decay in chiral effective field theory: lepton number violation at dimension seven
• The minimal 3+2 neutrino model versus oscillation anomalies
• Towards complete leading-order predictions for neutrinoless double $\beta$ decay
• $N_{\mathrm{eff}}$ in low-scale seesaw models versus the lightest neutrino mass
• Uniting low-scale leptogeneses
• Determining the leading-order contact term in neutrinoless double $\mathbf{\beta }$ decay
• Effective portals to heavy neutral leptons
• ULYSSES: Universal LeptogeneSiS Equation Solver
• Exploding operators for Majorana neutrino masses and beyond
• Bounds on right-handed neutrino parameters from observable leptogenesis
• Large-$N_c$ analysis of two-nucleon neutrinoless double beta decay and charge-independence-breaking contact terms
• ULYSSES, Universal LeptogeneSiS Equation Solver: version 2
• HNL mass degeneracy: implications for low-scale seesaws, LNV at colliders and leptogenesis
• Neutrinoless double beta decay rates in the presence of light sterile neutrinos
• Hidden-Sector Neutrinos and Freeze-In Leptogenesis
• Robustness of ARS Leptogenesis in Scalar Extensions