Kaluza-Klein Dark Matter

A specific, well-motivated candidate particle arising from theories with extra spatial dimensions, such as Universal Extra Dimensions. In these models, every standard particle has a tower of massive partner particles, called Kaluza-Klein (KK) states, which correspond to the particle's momentum in the hidden, compactified dimensions. The lightest of these KK particles (LKP) is often stable due to a conserved momentum symmetry in the higher-dimensional space and becomes an excellent candidate for dark matter. It would interact only weakly with normal matter, primarily through annihilation into gamma rays, which could be detected by telescopes. This model elegantly connects the dark matter puzzle to a potential solution for the hierarchy problem in particle physics, unifying two great mysteries.