Exclusive Chromomagnetism in heavy-to-light FCNCs
Exclusive Chromomagnetism in heavy-to-light FCNCs
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DOI：
10.1103/physrevd.87.074008
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发表时间：
2012-12
影响因子：
5
通讯作者：
M. Dimou;J. Lyon;R. Zwicky
中科院分区：
文献类型：
--
作者：
M. Dimou;J. Lyon;R. Zwicky
我们用光锥和规则的方法计算了B/D态与轻介子加一个离壳层光子之间的色磁算符的矩阵元，通常用O8表示。这些矩阵元素与B？K？L+L？它们可以被视为众所周知的企鹅形状因子T1、2、3和fT的类似物。我们发现了一个大的CP均匀相，并对其进行了远距离的解释。我们将我们的结果与QCD因式分解进行了比较，对于QCD因式分解，旁观者光子发射是终点发散的。在我们的方法中使用的关联函数的解析结构允许在物理表上有一个复杂的反常阈值。讨论了异常阈值在求和规则方法中的意义和处理方法。
We compute matrix elements of the chromomagnetic operator, often denoted by O 8 , between B/D states and light mesons plus an off-shell photon by employing the method of light-cone sum rules at leading twist-2. These matrix elements are relevant for processes such as B?K ? l + l ? and they can be seen as the analogues of the well-known penguin form factors T 1,2,3 and f T . We find a large CP -even phase for which we give a long-distance interpretation. We compare our results to QCD factorization for which the spectator photon emission is end-point divergent. The analytic structure of the correlation function used in our method admits a complex anomalous threshold on the physical sheet. The meaning and handling within the sum rule approach of the anomalous threshold is discussed.