"5 MeV Anti-Muon μc 1 1 0 1 1 105. 6 MeV Muon antineutrino 0 1 0 0 1 < 0 . 5 MeV Charm quark c +2/3 2 +1/2 +1/6 3 ~1. 5 GeV Strange quark s -1/3 2 -1/2 +1/6 3 ~100 MeV Anti-charm antiquark cc -2/3 1 0 -2/3 ~1. 5 GeV Anti-strange antiquark sc +1/3 1 0 +1/3 ~100 MeV Generation 3 Tau τ -1 2 -1/2 -1/2 1 1. 784 GeV Tau neutrino ντ 0 2 +1/2 -1/2 1 < 70 MeV Anti-Tau τc 1 1 0 1 1 1. 784 GeV Tau antineutrino 0 1 0 0 1 < 70 MeV Top quark t +2/3 2 +1/2 +1/6 3 173 GeV Bottom quark b -1/3 2 -1/2 +1/6 3 ~4. Fitness Model7 GeV Anti-top antiquark tc -2/3 1 0 -2/3 173 GeV Anti-bottom antiquark bc +1/3 1 0 +1/3 ~4. 7 GeV * - These are not ordinary Abelian charges which can be added together but labels of Group representations of Lie groups. "

" The Higgs boson, which is predicted by the Standard Model, has not been observed as of 2005 (though some phenomena were observed in the last days of the LEP collider that could be related to the Higgs; one of the reasons to build the LHC is that the increase in energy is expected to make the Higgs observable). The first experimental deviation from the Standard Model came in 1998, when Super-Kamiokande published results indicating neutrino oscillation. This implied the existence of non-zero neutrino masses since massless particles travel at the speed of light and so do not experience the passage of time. The Standard Model did not accommodate massive neutrinos, because it assumed the existence of only "left-handed" neutrinos, which have spin aligned counter-clockwise to their axis of motion. If neutrinos have non-zero mass, they necessarily travel slower than the speed of light. Therefore, it would be possible to "overtake" a neutrino, choosing a reference frame in which its direction of motion is reversed without affecting its spin (making it right-handed). Since then, physicists have revised the Standard Model to allow neutrinos to have mass, which make up additional free parameters beyond the initial 19. Girl Model A further extension of the Standard Model can be found in the theory of supersymmetry, which proposes a massive supersymmetric "partner" for every particle in the conventional Standard Model. Supersymmetric particles have been suggested as a candidate for explaining dark matter. "