B * B π coupling using relativistic heavy quarks
B * B π coupling using relativistic heavy quarks
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使用相对论重夸克的 B * B π 耦合
DOI：
10.1103/physrevd.93.014510
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发表时间：
2015
影响因子：
5
通讯作者：
O. Witzel
中科院分区：
文献类型：
--
作者：
J. Flynn;P. Fritzsch;T. Kawanai;C. Lehner;C. Sachrajda;B. Samways;R. V. D. Water;O. Witzel
本文计算了格点QCD中的B*Bπ耦合。强矩阵元（Bπ| B*）与B介子手征微扰理论中的首阶低能常数直接相关。我们使用非微扰调谐的三叶草作用量直接在b夸克质量上进行计算，该作用量控制阶的离散化效应。|p→a| n为所有n。我们的分析是在RBC/UKQCD规范位形上进行的，使用畴壁费米子和Iwasaki规范作用量，在两个晶格间距a-1 = 1.729（25）GeV，a-1 = 2.281（28）GeV，和幺正π介子质量下降到290 MeV。我们实现了良好的统计精度和控制所有系统的不确定性，给出了在连续介质中和物理光夸克质量下的HMPPT耦合gb = 0.56（3）stat（7）sys的最终结果。此外，这是直接在物理b夸克质量上进行的第一次计算，并且位于人们期望在魅力质量和静态点上的先前结果之间进行插值的区域中。
We report on a calculation of the B*Bπ coupling in lattice QCD. The strong matrix element (Bπ|B*) is directly related to the leading order low-energy constant in heavy meson chiral perturbation theory (HMΧPT) for B mesons. We carry out our calculation directly at the b-quark mass using a non-perturbatively tuned clover action that controls discretization effects of order |p→a| and (ma)n for all n. Our analysis is performed on RBC/UKQCD gauge configurations using domain-wall fermions and the Iwasaki gauge action at two lattice spacings of a–1 = 1.729(25) GeV, a–1 = 2.281 (28) GeV, and unitary pion masses down to 290 MeV. We achieve good statistical precision and control all systematic uncertainties, giving a final result for the HMΧPT coupling gb = 0.56(3)stat(7)sys in the continuum and at the physical light-quark masses. Furthermore, this is the first calculation performed directly at the physical b-quark mass and lies in the region one would expect from carrying out an interpolation between previous results at the charm mass and at the static point.