A sub-GeV dark matter model

Understand

We propose an extension of the Standard Model gauge symmetry by the gauge group $U(1)_{T3R}$ in order to address the Yukawa coupling hierarchy between the third generation fermions and the first two generation fermions of the SM.

• We assume that only the right-handed fermions of the first two generations are charged under the $U(1)_{T3R}$.
• In addition to the new dark gauge boson, we have a dark scalar particle whose vacuum expectation value (vev) breaks the $U(1)_{T3R}$ symmetry down to $Z_2$ symmetry and also explains the hierarchy problem.
• A vev of $\cal O$(GeV) is required to explain the mass parameters of the light flavor sector naturally.