Higgs portal vector dark matter for $\mathrm{GeV}$ scale $\gamma$-ray excess from galactic center

Abstract

We show that the $\mathrm{GeV}$ scale $\gamma$-ray excess from the direction of the Galactic Center can be naturally explained by the pair annihilation of Abelian vector dark matter (VDM) into a pair of dark Higgs bosons $VV\to \varphi \varphi$, followed by the subsequent decay of $\varphi$ into $\varphi \to b\bar{b},\tau \bar{\tau }$. All the processes are described by a renormalizable VDM model with the Higgs portal, which is naturally flavor-dependent. Some parameter space of this scenario can be tested at the near future direct dark matter search experiments such as LUX and XENON1T.

Comments: 12 pages, 5 figures