This is quite possibly the most important physics discovery since the discovery of the bottom quark in 1977, certainly the most exciting. Discoveries since then of the top quark and Higgs are less important because they were expected by practically everyone.
Following the discovery of the Higgs, the discovery of the WIMP has had top priority. Its existence had earlier been suggested by observations by PAMELA and Fermi of gamma rays from the core of the Milky Way. As they say, “Even though the study described above is strongly suggestive of the annihilation of 35 GeV WIMP dark matter, by itself it is not sufficiently convincing to ease a number of reasonable concerns.” The strength of the gamma ray emission line was too weak to be easily explained by dark matter annihilation. The new WIMP result is “excess gamma-ray emission associated with all 25 of the known dwarf spheroidal galaxies that orbit the Milky Way. While the results of this study were formally negative, there does appear to be a small excess of gamma rays corresponding to decay of a 10-25 GeV WIMP into bottom quark-antiquark pairs. With a statistical significance of 2.5 sigma”. Not conclusive yet, but close to it.
But the real coup described in the linked article is the discovery of the “sterile neutrino”. Few physicists expected that – I certainly didn’t expect it, for purely selfish reasons. “observed signals from 73 bright and relatively nearby clusters of galaxies (and from) Chandra x-ray observations of the Perseus and Virgo galactic clusters (found) an unexplained emission line at an energy of 3.52 keV, consistent with the decay of a form of dark matter – a 7.1 keV sterile neutrino turning into a photon and an ordinary neutrino. The photon receives almost exactly half the energy of the original particle because of the tiny mass of an ordinary neutrino.
Looks like I need to swat up on the sterile neutrino.