Explicit Quark - hadron Duality in Heavy - light Meson Weak Decays in the ’ t Hooft Model
نویسنده
چکیده
We compute the nonleptonic weak decay width of a heavy-light meson in 1+1 spacetime dimensions with a large number of QCD colors (the ’t Hooft model) as a function of the heavy quark mass. In this limit, QCD is exactly soluble, and decay modes are dominated by two-particle final states. We compare the results to the tree-level partonic decay width of the heavy quark in order to test quark-hadron duality in this universe. We find that this duality is surprisingly well satisfied in the heavy quark limit, in that the difference between the sum of exclusive partial widths and the tree-level partonic width approaches a constant as M → ∞, and the deviation is well-fit by a small 1/M correction. We comment on the meaning of this conclusion and its implications for the use of quark-hadron duality in hadronic physics. 11.10.Kk, 11.15.Pg, 13.25-k Typeset using REVTEX [email protected] [email protected] 1
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Explicit quark-hadron duality in the limit of heavy quark mass is studied using the ’t Hooft model, where both partonic and hadronic amplitudes may be computed exactly. Results for weak decays of heavy mesons are presented for both standard spectator decays, where the duality limit is convincingly approached, and annihilation decays of the valence quark-antiquark pair, where the approach to asy...
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