As stated above, the most stable WIMP would be the one that would be found in the present Universe. The lightest, most stable WIMP is given the name of neutralino and has a mass of about 45 GeV. These particles are composed of the supersymmetric partners of the photon, the Z boson, and the Higgs Boson. The remarkable thing about neutralinos is that there is no standard model particle composed of the photon, the Z boson, and the Higgs Boson, so it is extremely remarkable and unique. Because a neutralino is a WIMP, we know it was only produced during the Big Bang. This means that if neutralinos are the only source of dark matter, that after annihilation, all of the neutralinos that survived, became the sole component of dark matter. In other words, there were enough neutralinos that survived after the expansion of the Universe to create the dark matter structures found today. (4, 5)