Operator product expansion for B-meson distribution amplitude and dimension-5 HQET operators
Operator product expansion for B-meson distribution amplitude and dimension-5 HQET operators
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DOI：
10.1016/j.physletb.2009.02.028
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发表时间：
2008-10
影响因子：
4.4
通讯作者：
H. Kawamura;Kazuhiro Tanaka Univ. of Liverpool;Juntendo Univ.
中科院分区：
文献类型：
--
作者：
H. Kawamura;Kazuhiro Tanaka Univ. of Liverpool;Juntendo Univ.
当B介子分布振幅的双局域重夸克有效理论算符在夸克场和反夸克场之间具有类轻距离t时，尺度∼1/t将UV区和IR区分开，从而分别导致辐射修正中的尖点奇异性和非微扰修正中的多粒子态混合。我们用算符乘积展开、d⩽5的局域算符和相应威尔逊系数的α阶辐射修正来同时处理这些臭名昭著的UV和IR行为。结果是在坐标空间中得到的，它表现为具有苏达科夫型双对数的威尔逊系数和具有附加胶子的高维算符。这一结果给出了t小于∼1和GeV−1的B介子分布幅度，表示为Λ‘=MB−，将两个额外的HQET参数作为维-5算符的矩阵元素。文中还讨论了这些新的HQET参数对与独占B衰变相关的积分λB的影响。
When the bilocal heavy-quark effective theory (HQET) operator for the B-meson distribution amplitude has a light-like distance t between the quark and antiquark fields, the scale ∼1/t separates the UV and IR regions, which induce the cusp singularity in radiative corrections and the mixing of multiparticle states in nonperturbative corrections, respectively. We treat these notorious UV and IR behaviors simultaneously using the operator product expansion, with the local operators of dimension d⩽5 and radiative corrections at order αsfor the corresponding Wilson coefficients. The result is derived in the coordinate space, which manifests the Wilson coefficients with Sudakov-type double logarithms and the higher-dimensional operators with additional gluons. This result yields the B-meson distribution amplitude for t less than ∼1 GeV−1, in terms of Λ¯=mB−mband the two additional HQET parameters as matrix elements of dimension-5 operators. The impact of these novel HQET parameters on the integral relevant to exclusive B decays, λB, is also discussed.