ar X iv : h ep - p h / 98 02 21 7 v 1 2 F eb 1 99 8 Hadronic B Decay
نویسنده
چکیده
We review recent experimental results from CLEO and LEP experiments on hadronic decays of hadrons containing b quarks 1. We discuss charm counting and the semileptonic branching fraction in B decays and the color suppressed amplitude in B decay. 1 Charm counting and the semileptonic branching fraction A complete picture of inclusive B decay is beginning to emerge from recent measurements by CLEO II and the LEP experiments. 1 These measurements can be used to address the question of whether the hadronic decay of the B meson is compatible with its semileptonic branching fraction. Three facts emerge from the experimental examination of inclusive B decay at the Υ(4S): n c = 1.10 ± 0.05 (1) where n c is the number of charm quarks produced per B decay from recent CLEO II results 3 and using B(D 0 → K − π +) = (3.91 ± 0.08 ± 0.17%). This value is the average of the CLEO and ARGUS model independent measurements using dileptons. 2 We note that the value used by the LEP Elec-troweak Working Group for B(b → Xℓν) = 11.16 ± 0.20% is only marginally consistent with the Υ(4S) results. The third quantity, B(b → c¯ cs), is calculated from the inclusive B → D s , B → (c¯ c)X, and B → Ξ c branching fractions, and is B(b → c¯ cs) = 14.0 ± 2.8%. (3) The above value is determined assuming no contribution from B → D decays, an assumption which can be checked using data and is discussed in further detail below. In the parton model, it is difficult to accomodate a low semileptonic branching fraction unless the hadronic width of the B meson is increased. 5 The explanations for the semileptonic branching fraction which have been proposed can be distinguished by expressing the hadronic width of the B meson 1
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تاریخ انتشار 1998