Moving nonrelativistic QCD for heavy-to-light form factors on the lattice
Moving nonrelativistic QCD for heavy-to-light form factors on the lattice
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DOI：
10.1103/physrevd.80.074505
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发表时间：
2009-06
影响因子：
5
通讯作者：
R. Horgan;L. Khomskii;S. Meinel;M. Wingate;K. Foley;G. Lepage;G. Hippel;A. Hart;E. Müller;C. Davies;A. Dougall;K. Wong
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文献类型：
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作者：
R. Horgan;L. Khomskii;S. Meinel;M. Wingate;K. Foley;G. Lepage;G. Hippel;A. Hart;E. Müller;C. Davies;A. Dougall;K. Wong
我们将非相对论量子色动力学(NRQCD)描述在相对于通常的离散化框架提升的晶格上。通过移动NRQCD，我们可以精确地处理因标架选择而产生的重夸克的动量。我们通过$\mathcal{O}(1/{m}^{2}，{v}_{\mathm{rel}}^{4})$推导出移动NRQCD，无论是在连续体中还是在具有$\mathcal{O}({a}^{4})$改进的格子上，都与目前使用的NRQCD作用一样精确。我们通过对2+1味晶格QCD中重-重(底)和重-轻(S)介子的两点关联器的计算，对形式论进行了广泛的检验，得到了能量漂移和外动量重整化的非微扰决定。并与微扰理论在数学{O}({确保数学{阿尔法}}S})$进行了比较。结果表明，移动NRQCD是有效的。特别地，我们证明了重-轻和重-重介子的衰变常数可以用很小的系统误差计算，甚至比用标准的NRQCD计算的动量大得多。
We formulate nonrelativistic quantum chromodynamics (NRQCD) on a lattice which is boosted relative to the usual discretization frame. Moving NRQCD allows us to treat the momentum for the heavy quark arising from the frame choice exactly. We derive moving NRQCD through $\mathcal{O}(1/{m}^{2},{v}_{\mathrm{rel}}^{4})$, as accurate as the NRQCD action in present use, both in the continuum and on the lattice with $\mathcal{O}({a}^{4})$ improvements. We have carried out extensive tests of the formalism through calculations of two-point correlators for both heavy-heavy (bottomonium) and heavy-light (${B}_{s}$) mesons in $2+1$ flavor lattice QCD and obtained nonperturbative determinations of energy shift and external momentum renormalization. Comparison to perturbation theory at $\mathcal{O}({\ensuremath{\alpha}}_{s})$ is also made. The results demonstrate the effectiveness of moving NRQCD. In particular we show that the decay constants of heavy-light and heavy-heavy mesons can be calculated with small systematic errors up to much larger momenta than with standard NRQCD.