" The Higgs boson is the only boson in the theory which is not a gauge boson; it has a special status in the theory, and has been the subject of some controversy. Gravitons, the bosons believed to mediate the gravitational interaction, are not accounted for in the Standard Model . There are twelve different types, or "flavours", of fermions in the Standard Model. Amongst the proton, neutron, and electron, those fermions which constitute the vast majority of matter, the Standard Model considers only the electron a fundamental particle. The proton and neutron are aggregates of smaller particles known as quarks, which are held together by the strong interaction. The fundamental fermions in the Standard Model are given in the table. Table Left handed fermions in the Standard Model Fermion (Left-handed) Symbol Electric charge Weak charge* Weak isospin Hypercharge Color charge* Mass** Generation 1 Electron e -1 2 -1/2 -1/2 1 0. Hot Model Picture511 MeV Electron neutrino νe 0 2 +1/2 -1/2 1 < 50 eV Positron ec 1 1 0 1 1 0. 511 MeV Electron antineutrino 0 1 0 0 1 < 50 eV Up quark u +2/3 2 +1/2 +1/6 3 ~5 MeV *** Down quark d -1/3 2 -1/2 +1/6 3 ~10 MeV *** Anti-up antiquark uc -2/3 1 0 -2/3 ~5 MeV *** Anti-down antiquark dc +1/3 1 0 +1/3 ~10 MeV *** Generation 2 Muon μ -1 2 -1/2 -1/2 1 105. "

" That year Ford produced more cars than all other automakers combined. The Model T was a great commercial success, and for years in the late 1910s and early 1920s it was estimated that more than half of all motorcars in existence in the world were Model T Fords. In fact, it was so successful that Ford did not purchase any advertising between 1917 and 1923; in total, more than 15 million Model Ts were manufactured, more than any other model of automobile for almost a century. This record has now been surpassed by the Volkswagen Beetle, and the Toyota Corolla and Ford F-Series nameplates have both sold more. The record is currently held by the Volkswagen Golf which sold over 21,000,000 units and is still in production today. It was sold in the beginning at a price of $850 when competing cars often cost $2000-$3000. By the 1920s the price had fallen to $300 (about $3,300 in 2005 inflation-adjusted dollars) because of increasing efficiencies of assembly line technique and volume. Hot Indian Model On May 27, 1927, Ford Motor Company stopped manufacturing Model T cars. However Model T motors continued to be produced until August 4, 1941. "