Two – Loop Matrix Element of the Current – Current Operator in the Decay B → X s γ
نویسندگان
چکیده
We evaluate the important two–loop matrix element 〈sγ|Q2|b〉 of the operator (c̄γPLb) (s̄γμPLb) contributing to the inclusive radiative decay B → Xsγ. The calculation is performed in the NDR scheme, by means of asymptotic expansions method. The result is given as a series in z ≡ m2c/m2b up to O(z6). We confirm the result of Greub, Hurth and Wyler obtained by a different method up to O(z3). Higher–order terms are found to be numerically insignificant.
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تاریخ انتشار 2008