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arXiv 1306.6939hep-phhep-latnucl-th
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格点量子色动力学中的核σ项和标量-等标WIMP-核相互作用

Nuclear σ-terms and Scalar-Isoscalar WIMP-Nucleus Interactions from Lattice QCD

S. R. Beane, S. D. Cohen, W. Detmold, H. -W. Lin, M. J. Savage

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journal version
发表信息：
Phys. Rev. D 89, 074505 (2014)
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摘要：

在核有效场论的背景下，主要的标量-等序WIMP-核相互作用得到参数增强的贡献。这些贡献来自介子交换电流（MEC），并可能将这些相互作用的脉冲近似估计值修改10- 60%。我们指出，这些MEC也有助于夸克质量依赖的核结合能，即核σ项。在这项工作中，我们使用最近的格点量子色动力学计算的结合能的氘核，He-3和He-4在π介子质量接近500 MeV和800 MeV，结合实验确定的结合能的物理点，提供近似确定的σ项为这些轻核。对于每个核，我们发现相应的核σ项与单核子估计的偏差在百分之几的水平上，这与限制增强相矛盾。因此，格点量子色动力学计算目前表明，由基本WIMP与夸克的相互作用产生的标量-等压线WIMP-核相互作用的截面不会由于增强的介子交换流而受到显著的不确定性。

英文摘要：

It has been argued that the leading scalar-isoscalar WIMP-nucleus interactions receive parametrically enhanced contributions in the context of nuclear effective field theories. These contributions arise from meson-exchange currents (MECs) and potentially modify the impulse approximation estimates of these interactions by 10--60%. We point out that these MECs also contribute to the quark mass dependence of nuclear binding energies, that is, nuclear σ-terms. In this work, we use recent lattice QCD calculations of the binding energies of the deuteron, He-3 and He-4 at pion masses near 500 MeV and 800 MeV, combined with the experimentally determined binding energies at the physical point, to provide approximate determinations of the σ-terms for these light nuclei. For each nucleus, we find that the deviation of the corresponding nuclear σ-term from the single-nucleon estimate is at the few percent level, in conflict with the conjectured enhancement. As a consequence, lattice QCD calculations currently indicate that the cross sections for scalar-isoscalar WIMP-nucleus interactions arising from fundamental WIMP interactions with quarks do not suffer from significant uncertainties due to enhanced meson-exchange currents.

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