Nonperturbative Explanation of the Enhancement Factors in QCD Sum Rule for the ρ Meson
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چکیده
Taking the sum rule for the ρ meson as an example, we study the possibility of explaining the phenomenological enhancement factors for certain terms in the vacuum expectation value of the operator product expansion in the QCD sum rule. We take a QCD motivated extended Nambu-Jona-Lasinio (ENJL) model as the low energy effective Lagrangian for QCD with which we calculate the nonperpturbative contributions to the vaccum condensate expansion to obtain the enhancement factors. Our result shows that such nonperturbative contrbutions can cause large enough enhancement factors which can be consistent with the phenomenological values. PACS numbers: 11.55.Hx, 12.38.-t, 11.15.Pg Typeset Using REVTEX
منابع مشابه
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تاریخ انتشار 1997