分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-09-17
摘要: Using the framework of the Heavy Quark Effective Theory we have re-analyzed the Isgur-Wise function describing semileptonic #3;b → #3;c decays in the QCD sum rule approach.The slope parameter of the Isgur-Wise function is found to be ρ2 = 1.35 ± 0.12, which isconsistent with an experimental measurement and a lattice calculation. To O(1/mb, 1/mc)of the heavy quark expansion the integrated #3;b decay width is used to extract the CKM matrix element Vcb for which we obtain a value of |Vcb| = 0.041±0.004 in excellent agreementwith the value of |Vcb| determined from semileptonic B → D∗ decays.