Short-distance analysis of mixing

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• 作者：Eugene Golowich and Alexey A. Petrov
• 刊名：Physics Letters B
• 出版年：2005
• 出版时间：2005
• 年：2005
• 卷：625
• 期：1-2
• 页码：53-62
• 全文大小：146 K

文摘

We study the Standard Model short-distance prediction for the mass and lifetime differences between the two neutral D meson mass eigenstates. We find that, despite α_s/4π suppression, next-to-leading order (NLO) short-distance QCD corrections exceed the corresponding leading order (LO) amplitudes. For the lifetime difference, this stems from the lifting of helicity suppression of a light-quark intermediate state. We find y_D is given by y_NLO to a reasonable approximation but x_D is greatly affected by destructive interference between x_LO and x_NLO. The net effect is to render y_Dx_D6×10⁻⁷. Our NLO short-distance results, still smaller than most long-distance estimates, depend on the same two nonperturbative matrix elements of four-quark operators as in leading order.