Speaker
Description
We consider a two-step freeze-in mechanism of a singlet fermionic dark matter (DM) $\chi$ in a gauged $U(1)_{B-3L_i}$, $i \in \{e,\mu,\tau\}$, extension of the Standard model (SM). The DM communicates with the SM only through flavorful vector-portal $Z_{B3L}$ due to its non-trivial charge $x$ under $U(1)_{B-3L_i}$, which also guarantees the stability of the DM over the age of the Universe for $x \neq \{\pm 3/2, \pm 3\}$. We derive constraints on the gauge coupling $g_{B3L}$ that guarantees to produce the correct observed relic abundance of DM, considering $Z_{B3L}$ to lie within the mass range of a few MeV up to a few GeV. We show, that various current and future proposed intensity frontier experiments will still be able to probe the tiny couplings required for DM freeze-in. Hence, one may be able to see the imprints of non-thermal DM which escaped detection prospects in DM direct searches.
