PHYSICAL REVIEW D 109, 115022 (2024)

ISSN: 2470-0010, SCIE

Questions of flavor physics and neutrino mass from a flipped hypercharge

Duong Van Loi , Phung Van Dong, Nguyen Tuan Duy, Do Huy Thao

The flavor structure of quarks and leptons is not yet fully understood, but it hints a more fundamental theory of nonuniversal generations. We therefore propose a simple extension of the Standard Model by flipping (i.e., enlarging) the hypercharge Uð1ÞY to Uð1ÞX ⊗ Uð1ÞN for which both X and N depend on generations of both quark and lepton. By anomaly cancellation, this extension not only explains the existence of just three fermion generations as observed but also requires the presence of a right-handed neutrino per generation, which motivates seesaw neutrino mass generation. Furthermore, in its minimal version with a scalar doublet and two scalar singlets, the model naturally generates the measured fermionmixing matrices while it successfully accommodates several flavor anomalies observed in the neutral meson mixings, B-meson decays, lepton-flavor-violating processes of charged leptons, as well as satisfying constraints from particle colliders.

DOI: 10.1103/PhysRevD.109.115022