摘要
The b quark belongs to the third generation of quarks and is the weak-doublet partner of the t quark. The existence of the third-generation quark doublet was proposed in 1973 by Kobayashi and Maskawa [1] in their model of the quark mixing matrix （＂CKM＂ matrix）, and confirmed four years later by the first observation of a bb meson [2]. In the KM model, CP violation is explained within the Standard Model （SM） by an irreducible phase of the 3 × 3 unitary matrix. The regular pattern of the three lepton and quark families is one of the most intriguing puzzles in particle physics. The existence of families gives rise to many of the free parameters in the SM, including the fermion masses, and the elements of the CKM matrix.
The b quark belongs to the third generation of quarks and is the weak-doublet partner of the t quark. The existence of the third-generation quark doublet was proposed in 1973 by Kobayashi and Maskawa [1] in their model of the quark mixing matrix （＂CKM＂ matrix）, and confirmed four years later by the first observation of a bb meson [2]. In the KM model, CP violation is explained within the Standard Model （SM） by an irreducible phase of the 3 × 3 unitary matrix. The regular pattern of the three lepton and quark families is one of the most intriguing puzzles in particle physics. The existence of families gives rise to many of the free parameters in the SM, including the fermion masses, and the elements of the CKM matrix.
