Inelastic dark matter and baryon flavor symmetry in light of LUX-ZEPLIN (LZ) experiment

We present a novel model for inelastic dark matter in a simple extension of the Standard Model (SM) with a local U(1)' baryon flavor symmetry, such as U(1) B i-B j with i not equal to j. In this framework, we realize a realistic flavor structure for the mixing Yukawa couplings due to higher dimensional operators or renormalizable couplings between the SM quarks and extra vector-like quarks that are anomaly-free by themselves. We regard a Dirac singlet fermion as being dark matter and obtaining a small mass splitting for inelastic dark matter, only after the U(1)' symmetry is broken spontaneously. In particular, in the scenarios of heavy dark matter of 1, TeV mass, we show that there is a consistent parameter space for explaining both the LZ nuclear recoil event and the correct relic density for dark matter and the existing collider and indirect detection bounds are satisfied at the same time. In this case, we predict a relatively light Z' boson with 10-20, GeV mass and a weak gauge coupling, suggesting a dedicated search at colliders.