Factorization and the soft overlap contribution to heavy-to-light form factors
Factorization and the soft overlap contribution to heavy-to-light form factors
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DOI：
10.1016/j.nuclphysb.2004.04.025
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发表时间：
2003-11
期刊：
影响因子：
--
通讯作者：
B. Lange;M. Neubert
中科院分区：
文献类型：
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作者：
B. Lange;M. Neubert
使用软共线有效理论的形式主义，一个完整的分离的短距离和长距离的贡献重到轻的过渡形状因子在大反冲。在有效理论中，根据矩阵元素定义了参数化对形状因子的“软重叠”贡献的通用函数EWM（E）。端点配置对应于运动学的情况下，其中一个价部分子在外部介子进行非常小的动量占运营商涉及软共线信使领域。它们在ΛQCD/E和破坏因子分解中起主导作用。在有效理论中对算符混合和重整化群演化的分析表明，中间尺度EΛ对软函数<$M（E）没有意义，并且软重叠贡献没有受到显著的微扰（Sudakov）抑制。
Using the formalism of soft-collinear effective theory, a complete separation of short- and long-distance contributions to heavy-to-light transition form factors at large recoil is performed. The universal functions ζM(E) parameterizing the “soft overlap” contributions to the form factors are defined in terms of matrix elements in the effective theory. Endpoint configurations corresponding to kinematic situations where one of the valence partons in the external mesons carries very small momentum are accounted for in terms of operators involving soft-collinear messenger fields. They contribute at leading order in ΛQCD/E and spoil factorization. An analysis of operator mixing and renormalization-group evolution in the effective theory reveals that the intermediate scale EΛ is without significance to the soft functions ζM(E), and that the soft overlap contribution does not receive a significant perturbative (Sudakov) suppression.