The hadronic vacuum polarization and automatic O ( a ) improvement for twisted mass fermions
The hadronic vacuum polarization and automatic O ( a ) improvement for twisted mass fermions
复制标题
扭曲质量费米子的强子真空极化和自动O ( a )改进
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
K. Jansen
中科院分区：
文献类型：
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作者：
M. Petschlies;K. Jansen
真空极化张量和相应的真空极化函数是计算格点QCD中大量观测量的基础。例子是强子对轻子反常磁矩的贡献，电弱耦合和强耦合的运行以及夸克质量。从真空极化张量导出的电流项通常涉及位置空间中所有距离上的电流项的总和，从而导致短距离项的出现。O（a）改进的机制，在存在这样的短距离的条款是不直接涵盖的通常参数的壳上改进的行动和运营商为一个给定的数量。如果出现这种短距离贡献，则需要重新考虑O（a）改进的性质。我们讨论了这些短距离项对扭曲质量格点QCD真空极化函数的影响，发现即使在这些短距离项存在的情况下，如果理论被调谐，O（a）的自动改进仍然存在
The vacuum polarization tensor and the corresponding vacuum polarization function are the basis for calculations of numerous observables in lattice QCD. Examples are the hadronic contributions to lepton anomalous magnetic moments, the running of the electroweak and strong couplings and quark masses. Quantities which are derived from the vacuum polarization tensor often involve a summation of current correlators over all distances in position space leading thus to the appearance of short-distance terms. The mechanism of O(a) improvement in the presence of such short-distance terms is not directly covered by the usual arguments of on-shell improvement of the action and the operators for a given quantity. If such short-distance contributions appear, the property of O(a) improvement needs to be reconsidered. We discuss the effects of these short-distance terms on the vacuum polarization function for twisted mass lattice QCD and find that even in the presence of such terms automatic O(a) improvement is retained if the theory is tuned
影响因子：
5.4
作者：
R. Baron;P. Boucaud;Jaume Carbonell;A. Deuzeman;V. Drach;F. Farchioni;V. Giménez;G. Herdoiza
通讯作者：
R. Baron;P. Boucaud;Jaume Carbonell;A. Deuzeman;V. Drach;F. Farchioni;V. Giménez;G. Herdoiza