A boson notated with this letter is the weak hypercharge gauge boson and can mix with W3 to form the Z boson and photon. A set of four mesons symbolized by this letter includes the heaviest [emphasize] charged meson, as well as the heaviest neutral mesons to undergo matter-antimatter oscillations. A quantum number represented by this letter equals one-third of the quantity number of quarks minus the number of antiquarks, and is conserved in the Standard Model along with (*) L. The upsilon meson is made up of a quark of this letter paired with its antiquark. Yellow is the anticolor of this color state, the alphabetically first of three. This letter represents the second-heaviest quark, which is paired with the top quark in the third (10[1])generation. For 10 (10[1])points, name this (10[1])letter which, along with r and (10[2])g, constitutes color (10[2])charge. ■END■