Gamma-ray line from electroweakly interacting non-abelian spin-1 dark matter

Understand

We study gamma-ray line signatures from electroweakly interacting non-abelian spin-1 dark matter (DM).

• In this model, $Z_2$-odd spin-1 particles including a DM candidate have the SU(2)$_L$ triplet-like features, and the Sommerfeld enhancement is relevant in the annihilation processes.
• We derive the annihilation cross sections contributing to the photon emission and compare with the SU(2)$_L$ triplet fermions, such as Wino DM in the supersymmetric Standard Model.
• The Sommerfeld enhancement factor is approximately the same in both systems, while our spin-1 DM predicts the larger annihilation cross sections into $\gamma \gamma/ Z \gamma$ modes than those of the Wino by $\frac{38}{9}$.