AI 中文总结
本研究针对质量小于1 MeV的太阳轴子，利用氙靶估算其耦合的探测前景，发现下一代氙气实验有望超越Borexino的约束，获得与JUNO、Hyper-Kamiokande相当的灵敏度，并给出了不同曝光量下的耦合探测下限。
AI 中文摘要
由同位矢量耦合$g_{3aN}$诱导的单色5.49 MeV太阳轴子，可在暗物质直接探测实验中被搜寻。本文针对轴子质量$m_a < 1$ MeV的情况，利用氙靶估算了相关轴子耦合的探测前景。在轴子-电子耦合$g_{ae}$的作用下，信号主要由轴子诱导的$e^+ e^-$对产生过程主导，当轴子质量接近电子质量的两倍时，该过程的截面会大幅增强；此外，该截面还与原子序数的平方$Z^2$相关。这使得下一代氙气实验有望超越当前Borexino实验的约束，获得与JUNO、Hyper-Kamiokande等大型中微子探测器相当的灵敏度。在200吨·年和1000吨·年的曝光量下，90%置信水平下可探测的耦合$|g_{3aN}g_{ae}|$下限分别为$1.59\times10^{-14}$和$7.12\times10^{-15}$；若轴子与光子耦合，对应的$|g_{3aN}g_{a\gamma}|$的预测灵敏度下限则分别可达$6.76\times10^{-12}$ GeV$^{-1}$和$3.02\times10^{-12}$ GeV$^{-1}$。
英文摘要
The monochromatic 5.49 MeV solar axions induced by the isovector coupling $g_{3aN}$ can be searched for at the dark matter direct detection experiments. In this paper we estimate the prospects of the relevant axion couplings for axion mass $m_{a} <$ 1 MeV with xenon targets. Given the axion-electron coupling $g_{ae}$, the signal is dominated by the axion-induced $e^+ e^-$ pair production whose cross section is largely enhanced when the axion mass approaches twice of the electron mass. Furthermore, the cross section depends on the atomic number squared $Z^2$. This allows the next-generation xenon experiments to surpass the current Borexino constraints and provide sensitivities competitive with those of the large neutrino detectors such as JUNO and Hyper-Kamiokande. With an exposure of 200 and 1000 ton$\cdot$yr, the couplings $|g_{3aN} g_{ae}|$ can be probed down to $1.59\times10^{-14}$ and $7.12\times10^{-15}$ at 90% C.L., respectively. If the axion couples to photons, the projected sensitivities on $|g_{3aN}g_{aγ}|$ can touch down to $6.76\times10^{-12}$ GeV$^{-1}$ and $3.02\times10^{-12}$ GeV$^{-1}$, respectively.
Comments27 pages, 8 figures and 2 tables
