Natural mass hierarchy among three heavy Majorana neutrinos for resonant leptogenesis under modular A 4 symmetry

• Published in: The journal of high energy physics Vol. 2022; no. 7; pp. 1 - 19
• Main Authors: Dong Woo Kang, Jongkuk Kim, Takaaki Nomura, Hiroshi Okada
• Format: Journal Article
• Language: English
• Published: SpringerOpen 01.07.2022
• Subjects: Baryo-and Leptogenesis; Cosmology of Theories BSM; Sterile or Heavy Neutrinos
• ISSN: 1029-8479
• DOI: 10.1007/JHEP07(2022)050

Abstract It is clear that matter is dominant in the Universe compared to antimatter. We call this problem baryon asymmetry. The baryon asymmetry is experimentally determined by both cosmic microwave background and big bang nucleosynthesis measurements. To resolve the baryon number asymmetry of the Universe as well as neutrino oscillations, we study a radiative seesaw model in a modular A 4 symmetry. Degenerate heavy Majorana neutrino masses can be naturally realized in an appropriate assignments under modular A 4 with large imaginary part of modulus τ, and it can induce measured baryon number via resonant leptogenesis that is valid in around TeV scale energy theory. We also find that the dominant contribution to the CP asymmetry arises from Re[τ] through our numerical analysis satisfying the neutrino oscillation data.