Majoron-driven leptogenesis in gauged U ( 1[italic] )[/italic] L [italic] -L[/italic] model

We propose a novel leptogenesis scenario in the gauged U(1)L-L model. Achieving successful leptogenesis in the U(1)L-L symmetric phase is challenging due to the absence of a CP phase, caused by restriction from the gauge symmetry. To overcome this issue, we introduce an additional global symmetry, U(1)B-L, and a scalar field responsible for breaking this symmetry. Through the kinetic misalignment mechanism, the Majoron field associated with U(1)B-L symmetry breaking has a kinetic motion in the early Universe. Subsequently, time-dependent Majoron field background induces the background CP phase dynamically, leading to successful leptogenesis in the U(1)L-L symmetric phase. Furthermore, Majoron itself serves as a dark matter candidate in this scenario. As one of the phenomenological applications, we consider the model that can also explain the muon g-2 anomaly.