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.
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： A supersymmetric model with two copies of the StandardModel gauge groups is constructed in the gauge mediated supersymmetry breaking scenario. The supersymmetry breaking messengers are in a simple form. The Standard Model is obtained after first step gauge symmetry breaking. In the case of one copy of the gauge interactions being strong, a scenario of electroweak symmetry breaking is discussed, and the gauginos are generally predicted to be heavier than the sfermions.
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： The B → πℓν weak decay form factors are calculated via light-cone sum rules within the framework of the heavy quark effective theory. We calculate the leading and the relevant sub-leading universal form factors. Our results are matched to the known soft pion limit. We also address the large pion energy limit of our sum rule results. Our results are compared with that of other approaches.
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