期刊
NUCLEAR PHYSICS B
卷 605, 期 1-3, 页码 558-578出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/S0550-3213(01)00194-8
关键词
B-meson decays; quantum chromodynamics; sum rules
A new method is suggested to calculate the B --> pi pi hadronic matrix elements from QCD light-cone Sum rules. To leading order in alpha (s) and 1/m(b), the sum rule reproduces a factorizable matrix element. in accordance with the prediction of the QCD factorization approach. Whereas the QCD factorization can only take into account the nonfactorizable corrections induced by hard-gluon exchanges, the method suggested here also allows a systematic inclusion of soft-gluon effects. In this paper, I concentrate on the latter aspect and present a calculation of the nonfactorizable soft-gluon exchange contributions to B --> pi pi. The result, including twist 3 and 4 terms, is suppressed by one power of 1/m(b) with respect to the factorizable amplitude. Despite its numerical smallness, the soft effect is at the same level as the O(alpha (s)) correction to the QCD factorization formula for B --> pi pi. The method suggested here can be applied to matrix elements of different topologies and operators and to various other B-decay channels. I also comment on the earlier applications of QCD sum rules to nonleptonic decays of heavy mesons. (C) 2001 Published by Elsevier Science B.V.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据