A. Introduction The top quark is the Q = 2/3, T3 = ＋1/2 member of the weak-isospin doublet containing the bottom quark （see the review on the ＂Electroweak Model and Constraints on New Physics＂ for more information...A. Introduction The top quark is the Q = 2/3, T3 = ＋1/2 member of the weak-isospin doublet containing the bottom quark （see the review on the ＂Electroweak Model and Constraints on New Physics＂ for more information）. Its phenomenology is driven by its large mass. Being heavier than a W boson, it is the only quark, that decays semi-weakly, i.e., into a real W boson and a b quark. Therefore, it has a very short lifetime and decays before hadronization can occur. In addition, it is the only quark whose Yukawa coupling to the Higgs boson is order of unity. For these reasons the top quark plays a special role in the Standard Model （SM） and in many extensions thereof.展开更多
文摘A. Introduction The top quark is the Q = 2/3, T3 = ＋1/2 member of the weak-isospin doublet containing the bottom quark （see the review on the ＂Electroweak Model and Constraints on New Physics＂ for more information）. Its phenomenology is driven by its large mass. Being heavier than a W boson, it is the only quark, that decays semi-weakly, i.e., into a real W boson and a b quark. Therefore, it has a very short lifetime and decays before hadronization can occur. In addition, it is the only quark whose Yukawa coupling to the Higgs boson is order of unity. For these reasons the top quark plays a special role in the Standard Model （SM） and in many extensions thereof.
