Phenomenology of the simplest linear seesaw mechanism

• Published in: The journal of high energy physics Vol. 2023; no. 7; pp. 221 - 48
• Main Authors: Batra, Aditya, Bharadwaj, Praveen, Mandal, Sanjoy, Srivastava, Rahul, Valle, José W. F.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 28.07.2023; Springer Nature B.V; SpringerOpen
• Subjects: Baryon/Lepton Number Violation; Classical and Quantum Gravitation; Decay; Elementary Particles; Higgs bosons; High energy physics; Leptons; Mediators; Neutrinos; Other Weak Scale BSM Models; Phenomenology; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; Signatures; Specific BSM Phenomenology; Standard model (particle physics); Sterile or Heavy Neutrinos; String Theory; Symmetry; Other Weak Scale BSM Models; Specific BSM Phenomenology; Sterile or Heavy Neutrinos; Baryon/Lepton Number Violation
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP07(2023)221

A bstract The linear seesaw mechanism provides a simple way to generate neutrino masses. In addition to Standard Model particles, it includes quasi-Dirac leptons as neutrino mass mediators, and a leptophilic scalar doublet seeding small neutrino masses. Here we review its associated physics, including restrictions from theory and phenomenology. The model yields potentially detectable μ → eγ rates as well as distinctive signatures in the production and decay of heavy neutrinos ( N i ) and the charged Higgs boson ( H ± ) arising from the second scalar doublet. We have found that production processes such as e + e − → NN , e − γ → NH − and e + e − → H + H − followed by the decay chain H ± → ℓ i ± N , N → ℓ j ± W ∓ leads to striking lepton number violation signatures at high energies which may probe the Majorana nature of neutrinos.