Resonant Leptogenesis in Minimal U\((1)_X\) Extensions of the Standard Model

We investigate a general U\((1)_X\) scenario where we introduce three generations of Standard Model (SM) singlet right-handed neutrinos (RHNs) to generate the light neutrino mass through the seesaw mechanism after the breaking of U\((1)_X\) and electroweak symmetries. In addition to that, a general U\((1)_X\) scenario involves an SM-singlet scalar field and due to the U\((1)_X\) symmetry breaking, the mass of a neutral beyond the SM (BSM) gauge boson \(Z^\prime \) is evolved. The RHNs, being charged under the U\((1)_X\) scenario, can explain the origin of the observed baryon asymmetry through the resonant leptogenesis process. Applying observed neutrino oscillation data, we study \(Z^\prime \) and BSM scalar-induced processes to reproduce the observed baryon asymmetry. Hence, we estimate bounds on the U\((1)_X\) gauge coupling and the mass of the \(Z^\prime \) for different U\((1)_X\) charges and benchmark masses of RHN and SM-singlet scalar. Finally, we compare our results with limits obtained from the existing limits from LEP-II and LHC. Abstract Published by the Jagiellonian University 2025 authors