Cosmic-ray antiproton excess from annihilating tensor dark matter

Abstract

In this paper we calculate the antiproton production in the annihilation of tensor dark matter and explore the possibility that the excess of antiprotons in the range $E_{K}=10-20 ~GeV$ reported by several groups in the analysis of the AMS-02 Collaboration data is due to this production mechanism. We find that these contributions improve the fit to the data on the antiproton to proton ratio for the narrow window $M\in [62.470,62.505] \text{ GeV}$ for the tensor dark matter mass and $g_s \in [0.98,1.01]\times 10^{-3}$ for the Higgs portal coupling in the effective theory. These are precisely the range of values compatible with several experimental constraints, such as dark matter relic density, limits on the spin-independent dark matter-nucleon cross-section from XENON1T, indirect detection limits for the annihilation of dark matter into $\bar{b}b$, $τ^+ τ^-$, $μ^+ μ^-$ and $γγ$, as well as with the gamma-ray excess at the Milky Way galactic center.