Muonphilic Dark Matter explanation of gamma-ray galactic center excess: a comprehensive analysis

The Galactic center gamma-ray excess (GCE) is a long-standing unsolved problem. One of candidate solutions, the dark matter (DM) annihilation, has been recently tested with other astrophysical observations, such as AMS-02 electron-positron spectra, Fermi Dwarf spheroidal galaxies gamma ray data, and so on. It has been claimed that only the DM annihilation to a muon-pair, namely muonphilic DM, is compatible with the null detection of all the corresponding astrophysical measurements [Di Mauro and Winkle (2021)]. On the other hand, a muonphilic DM model may also lead to a signal in the recent muon g-2 measurement or the latest PandaX-4T limit. In this work, we comprehensively study interactions between DM and muon, including different DM and mediator spins. In agreement with GCE (not only $2\mu$ but also $4\mu$ final states), we test these interactions against all the thermal DM constraints. Our results show that only the parameter space near the mediator resonance region can explain GCE and relic density simultaneously. Regardless of the DM spin, only the interactions with the spin-0 mediator can explain the recent muon g-2 excess on top of GCE, relic density, and other DM and mediator constraints.