Migdal effect and photon bremsstrahlung in effective field theories of dark matter direct detection and coherent elastic neutrino-nucleus scattering
Migdal effect and photon bremsstrahlung in effective field theories of dark matter direct detection and coherent elastic neutrino-nucleus scattering
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DOI：
10.1103/physrevd.101.015012
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发表时间：
2019-05
影响因子：
5
通讯作者：
N. Bell;J. Dent;J. Newstead;S. Sabharwal;T. Weiler
中科院分区：
文献类型：
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作者：
N. Bell;J. Dent;J. Newstead;S. Sabharwal;T. Weiler
暗物质直接探测实验对轻暗物质（低于几个GeV）的灵敏度有限，这是由于将探测核反冲的能量阈值降低到$O（keV）$以下的挑战。虽然在这方面已经取得了令人印象深刻的进展，但亮暗物质仍然是暗物质参数空间中约束最少的区域。已经表明，由于米格达尔效应和相干发射的光子韧致辐射的电离和激发从反冲原子可以提供可观察的通道，否则会错过了由于所产生的核反冲下降到探测器阈值以下的轻暗物质。在本文中，我们通过计算Migdal效应和光子韧致辐射率为一组一般的相互作用类型，包括那些动量独立或依赖，自旋独立或依赖，以及检查各种目标材料的速率，使我们能够把新的实验限制在这些相互作用类型。此外，我们还计算了太阳或大气中微子在原子核上的相干散射所引起的这些效应。我们表明，米格达尔效应占主导地位的韧致辐射效应的所有目标考虑由暗物质或中微子引起的相互作用。这减少了光子韧致辐射到无关的未来直接探测实验。
Dark matter direct detection experiments have limited sensitivity to light dark matter (below a few GeV), due to the challenges of lowering energy thresholds for the detection of nuclear recoil to below $\mathcal{O}(\mathrm{keV})$. While impressive progress has been made on this front, light dark matter remains the least constrained region of dark-matter parameter space. It has been shown that both ionization and excitation due to the Migdal effect and coherently emitted photon bremsstrahlung from the recoiling atom can provide observable channels for light dark matter that would otherwise have been missed owing to the resulting nuclear recoil falling below the detector threshold. In this paper we extend previous work by calculating the Migdal effect and photon bremsstrahlung rates for a general set of interaction types, including those that are momentum independent or dependent, spin independent or dependent, as well as examining the rates for a variety of target materials, allowing us to place new experimental limits on some of these interaction types. Additionally, we include a calculation of these effects induced by the coherent scattering on nuclei of solar or atmospheric neutrinos. We demonstrate that the Migdal effect dominates over the bremsstrahlung effect for all targets considered for interactions induced by either dark matter or neutrinos. This reduces photon bremsstrahlung to irrelevancy for future direct detection experiments.