Model of alternative to WIMPs takes steps forward

Science : Weakly interacting massive particles (WIMPs) are a hypothesized form of dark matter. According to the model that describes WIMPs, large numbers of the dark-matter particles formed in the early universe. When they interacted with each other, they decayed into normal particles. As the universe expanded, such interactions became rarer, leaving enough WIMPs in proportion to ordinary matter to fit astrophysical observations. Because no WIMPs have yet been directly detected, however, alternative theories have been proposed, including the existence of strongly interacting massive particles (SIMPs). In a new paper, Yonit Hochberg of Lawrence Berkeley National Laboratory and her colleagues argue that the production and elimination of SIMPs could have followed a similar pattern as that proposed for WIMPs. And because SIMPs are more likely to interact with regular matter, they should be easier to detect.