A light Higgs boson is preferred by $M_W$ and $m_t$ measurements. A complex scalar singlet addition to the standard model allows a better fit to these measurements through a new light singlet dominated state. It then predicts a light dark matter (DM) particle that can explain the signals of DM scattering from nuclei in the CoGeNT and DAMA/LIBRA experiments. Annihilations of this DM in the galactic halo, $AA\to b\overline{b}$, $c\overline{c}$, ${\tau }^{+}{\tau }^{-}$, lead to gamma rays that naturally improve a fit to the Fermi Large Area Telescope data in the central galactic regions. The associated light neutral Higgs boson may also be discovered at the Large Hadron Collider.

• Received 12 August 2010

DOI:https://doi.org/10.1103/PhysRevD.82.095011