Weakly Interacting Massive Particles

WIMPs (Weakly Interacting Massive Particles) - The long-reigning, prototypical candidate for cold dark matter. A WIMP is a hypothetical particle with a mass typically between 10 and 1000 times that of a proton, which interacts with ordinary matter only through the weak nuclear force and gravity. Its appeal lies in the "WIMP Miracle": a particle with weak-scale mass and interactions would be thermally produced in the hot Big Bang in almost exactly the right abundance to account for the observed dark matter density today. This elegant coincidence has driven decades of experimental searches using massive underground detectors (waiting for a WIMP to bump into a nucleus) and particle colliders like the LHC (trying to create one). While no definitive signal has been found, the WIMP paradigm remains a foundational and highly motivated target for the direct detection of the invisible universe.
For decades, the Standard Model insisted neutrinos were massless, ethereal ghosts. Then we found out they are not. They have this tiny, elusive mass, and they oscillate, changing their identity as they fly. It’s as if a beam of red light decided to turn into blue light halfway to its target. The universe is a glorious trickster.