Combined search in dwarf spheroidal galaxies for branon dark matter annihilation signatures with the MAGIC telescopes

Massive brane fluctuations, called branons, behave as weakly interacting massive particles, which is one of the most favored class of candidates to fulfill the role of the dark matter (DM), an elusive kind of matter beyond the Standard Model. We present a multi-target search in dwarf spheroidal galaxies for branon DM annihilation signatures with a total exposure of 354 hours with the ground-based gamma-ray telescope system MAGIC. This search led to the most constraining limits on branon DM in the sub-TeV and multi-TeV DM mass range. Our most stringent limit on the thermally-averaged annihilation cross-section (at $95\mathrm{\%}$ confidence level) corresponds to $⟨\sigma v⟩\simeq 1.9\times {10}^{-24}{\text{cm}}^3{\text{s}}^{-1}$ at a branon mass of $\sim 1.5\text{ TeV}$.