Non-Abelian vector boson as FIMP dark matter

In this analysis we demonstrate the freeze-in realization of a non-abelian vector boson dark matter (DM). We choose to elaborate an existing SU(2)(N) extension (N stands for neutral) of the Standard Model (SM) with an additional U(1) = S' global symmetry, which stabilizes the vector boson (X, (X) over bar) as DM through unbroken S = T3N + S' as the lightest odd S particle. Apart from showing the right order of the SU(2)(N) coupling (similar to 10(-12)-10(-13)) required for the correct relic of DM via freeze in, the analysis reveals that the contribution to the freeze-in production of DM from the decay of a heavier scalar bi-doublet zeta(0,+/-)(1) -> zeta(0,+/-)(2) X is equally important even after the decoupling of zeta(0,+/-)(1) from the thermal bath. This treatment of computing the relic abundance in context with freeze-in is practically model-independent and can be applied to all the scenarios where the DM is produced from the decay of a massive particle which was once in equilibrium with the thermal bath. This bi-doublet earlier was in equilibrium with the visible sector due to SM SU(2)(L) coupling. Moreover, the neutral component of SU(2)(N) scalar triplet (Delta), responsible for neutrino mass generation in this framework, turns out to serve as additional DMs in the model and offers a multipartite freeze-in DM set up to explore. The allowed parameter space is obtained after estimating constraints from CMB, BBN and AMS-02 bound. This exercise nicely complements the freeze-out realization of (X, (X) over bar) as weakly interacting massive particle (WIMP) and distinguishes it through stable charge track signature at collider compared to leptonic signal excess as in WIMP scenario.