从CDEX-10实验第一个102.8 kg ${\times}$天数据看轻弱相互作用大质量粒子的极限
Limits on Light Weakly Interacting Massive Particles from the First 102.8 kg ${\times}$ day Data of the CDEX-10 Experiment
H. Jiang, L. P. Jia, Q. Yue, K. J. Kang, J. P. Cheng, Y. J. Li, H. T. Wong, M. Agartioglu, H. P. An, J. P. Chang, J. H. Chen, Y. H. Chen, Z. Deng, Q. Du, H. Gon… 展开作者
H. Jiang, L. P. Jia, Q. Yue, K. J. Kang, J. P. Cheng, Y. J. Li, H. T. Wong, M. Agartioglu, H. P. An, J. P. Chang, J. H. Chen, Y. H. Chen, Z. Deng, Q. Du, H. Gong, L. He, J. W. Hu, Q. D. Hu, H. X. Huang, H. B. Li, H. Li, J. M. Li, J. Li, X. Li, X. Q. Li, Y. L. Li, B. Liao, F. K. Lin, S. T. Lin, S. K. Liu, Y. D. Liu, Y. Y. Liu, Z. Z. Liu, H. Ma, J. L. Ma, H. Pan, J. Ren, X. C. Ruan, B. Sevda, V. Sharma, M. B. Shen, L. Singh, M. K. Singh, T. X. Sun, C. J. Tang, W. Y. Tang, Y. Tian, G. F. Wang, J. M. Wang, L. Wang, Q. Wang, Y. Wang, S. Y. Wu, Y. C. Wu, H. Y. Xing, Y. Xu, T. Xue, L. T. Yang, S. W. Yang, N. Yi, C. X. Yu, H. J. Yu, J. F. Yue, X. H. Zeng, M. Zeng, Z. Zeng, F. S. Zhang, Y. H. Zhang, M. G. Zhao, J. F. Zhou, Z. Y. Zhou, J. J. Zhu, Z. H. Zhu
We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8 $\times 10^{-42}$ and 3 $\times 10^{-36}$ cm$^{2}$ at a 90\% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass ($m_χ$) of 5 GeV/${c}^2$ are achieved. The lower reach of $m_χ$ is extended to 2 GeV/${c}^2$.
中国暗物质实验（CDEX）的目标是在中国锦屏地下实验室（CJPL）直接搜索轻弱相互作用大质量粒子（WIMP），覆盖层约为2400米。报道了CDEX-1 994 g p型点接触锗（pPCGe）探测器的实验结果。研究计划的追求，以进一步降低物理阈值，通过改进硬件和数据分析。目前正在测试CDEX-10实验，其pPCGe阵列的目标质量范围为10公斤。本研究亦将介绍CDEX计划发展为“CDEX-1 T实验”的过程，其中包括使用吨级锗探测器阵列。
Results of direct dark matter detection with CDEX experiment at CJPL
中国暗物质实验（CDEX）位于中国锦屏地下实验室（CJPL），其覆盖层约为2400米，旨在直接搜索轻弱相互作用大质量粒子（WIMP）。单元件994克p型点接触（PPC）锗探测器（CDEX-1B）在固体被动屏蔽系统内运行。为了实现更低的背景，将原型10 kg PPC锗探测器阵列（CDEX-10）直接浸入液氮中，该原型10 kg PPC锗探测器阵列（CDEX-10）由三个探测器串组成，每个探测器串具有三个锗晶体。在160 eV的能量阈值下，分别用能谱和年度调制分析确定了WIMP与核散射的极限。在排除Migdal效应的基础上，对CDEX-1B的数据进行了重新分析，以寻找亚GeV的WIMP。最后，对CJPL-Ⅱ的CDEX实验的未来计划进行了介绍。
Constraints on Spin-Independent Nucleus Scattering with sub-GeV Weakly Interacting Massive Particle Dark Matter from the CDEX-1B Experiment at the China Jin-Ping Laboratory
We present the improved constraints on couplings of solar axions and more generic bosonic dark matter particles using 737.1 kg-days of data from the CDEX-1B experiment. The CDEX-1B experiment, located at the China Jinping Underground Laboratory, primarily aims at the direct detection of weakly interacting massive particles using a p-type point-contact germanium detector. We adopt the profile likelihood ratio method for analysis of data in the presence of backgrounds. An energy threshold of 160 eV was achieved, much better than the 475 eV of CDEX-1A with an exposure of 335.6 kg-days. This signi…
Dark matter (DM) direct detection experiments have been setting strong limits on the DM-nucleon scattering cross section at the DM mass above a few GeV, but leave large parameter space unexplored in the low mass region. DM is likely to be scattered and boosted by relativistic cosmic rays in the expanding universe if it can generate nuclear recoils in direct detection experiments to offer observable signals. Since low energy threshold detectors using Germanium have provided good constraints on ordinary halo GeV-scale DM, it is necessary to re-analyze 102.8 kg$\times$day data in the CDEX-10 expe…
We present weakly interacting massive particles (WIMPs) search results performed using two approaches of effective field theory from the China Dark Matter Experiment (CDEX), based on the data from both CDEX-1B and CDEX-10 stages. In the nonrelativistic effective field theory approach, both time-integrated and annual modulation analyses were used to set new limits for the coupling of WIMP-nucleon effective operators at 90% confidence level (C.L.) and improve over the current bounds in the low $m_χ$ region. In the chiral effective field theory approach, data from CDEX-10 were used to set an uppe…
We present new constraints on light dark matter boosted by cosmic rays (CRDM) using the 205.4 kg day data of the CDEX-10 experiment conducted at the China Jinping Underground Laboratory. The Monte Carlo simulation package CJPL\_ESS was employed to evaluate the Earth shielding effect. Several key factors have been introduced and discussed in our CRDM analysis, including the contributions from heavier CR nuclei than proton and helium, the inhomogeneity of CR distribution, and the impact of the form factor in the Earth attenuation calculation. Our result excludes the dark matter--nucleon elastic …
We present improved germanium-based constraints on sub-GeV dark matter via dark matter--electron ($χ$-$e$) scattering using the 205.4 kg$\cdot$day dataset from the CDEX-10 experiment. Using a novel calculation technique, we attain predicted $χ$-$e$ scattering spectra observable in high-purity germanium detectors. In the heavy mediator scenario, our results achieve 3 orders of magnitude of improvement for $m_χ$ larger than 80 MeV/c$^2$ compared to previous germanium-based $χ$-$e$ results. We also present the most stringent $χ$-$e$ cross-section limit to date among experiments using solid-state …
First search for light fermionic dark matter absorption on electrons using germanium detector in CDEX-10 experiment
Tsinghua University（清华大学）；Institute of Physics, Academia Sinica（中央研究院物理研究所）；NUCTECH Company（同方威视技术股份有限公司）；YaLong River Hydropower Development Company（雅砻江流域水电开发有限公司）
A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg$\cdot$day data taken from a p-type point contact germanium detector of CDEX-10 experiment at China Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption ($χ+A\rightarrow ν+A$) and DM-nucleus 3$\rightarrow$2 scattering ($χ+χ+A\rightarrow ϕ+A$), have been analyzed with an energy threshold of 160 eVee. No significant signal was found. Thus new limits on the DM-nucleon interaction cross section are set for both models at sub-GeV DM mass regio…
Search for Light Weakly-Interacting-Massive-Particle Dark Matter by Annual Modulation Analysis with a Point-Contact Germanium Detector at the China Jinping Underground Laboratory
We present constraints on the existence of weakly interacting massive particles (WIMPs) from an 11 kg-day target exposure of the DAMIC experiment at the SNOLAB underground laboratory. The observed energy spectrum and spatial distribution of ionization events with electron-equivalent energies $>$200 eV$_{\rm ee}$ in the DAMIC CCDs are consistent with backgrounds from natural radioactivity. An excess of ionization events is observed above the analysis threshold of 50 eV$_{\rm ee}$. While the origin of this low-energy excess requires further investigation, our data exclude spin-independent WIMP-n…
A natural broad energy germanium (BEGe) detector is operated in the China Jinping Underground Laboratory (CJPL) for a feasibility study of building the next generation experiment of the neutrinoless double-beta (0{$νββ$}) decay of $^{76}$Ge. The setup of the prototype facility, characteristics of the BEGe detector, background reduction methods, and data analysis are described in this paper. A background index of 6.4$\times$10$^{-3}$ counts/(keV$\cdot$kg$\cdot$day) is achieved and 1.86 times lower than our previous result of the CDEX-1 detector. No signal is observed with an exposure of 186.4 k…
Prospects for SIMPLE 2000: A large-mass, low-background Superheated Droplet Detector for WIMP searches
SIMPLE 2000（用于大质量粒子搜索的过热仪器）将包括一个由8至16个大活性质量（$\sim15$ g）过热液滴探测器组成的阵列，将安装在Rustrel Pays d 'Apt的新地下实验室中。有几个因素使SDD成为检测弱相互作用大质量粒子（WIMPs）的有吸引力的方法，即它们对最小电离粒子的固有不敏感性、高氟含量、低成本和在环境压力和温度附近操作。我们在这里评论的制造，校准和已经竞争的第一个限制从简单的原型喷雾干燥器，以及预期立即增加的灵敏度的计划，其目的是在2000年期间的接触$>$ 25千克-天。中等质量的富氟探测器的能力，探索区域的中性伴子参数空间超出了最雄心勃勃的低温项目的范围。
