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278 results on '"Fang, C. H."'

1. Search for solar axions by Primakoff effect with the full dataset of the CDEX-1B Experiment

Author

Yang, L. T., Liu, S. K., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, Q. J., Guo, T., Guo, X. Y., He, L., He, J. R., Hu, J. W., Huang, H. X., Huang, T. C., Jiang, L., Karmakar, S., Li, H. B., Li, H. Y., Li, J. M., Li, J., Li, M. C., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, J. X., Liu, Y. D., Liu, Y., Liu, Y. Y., Ma, H., Mao, Y. C., Nie, Q. Y., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Shen, M. B., Singh, M. K., Sun, T. X., Sun, W. L., Tang, C. J., Tian, Y., Wang, G. F., Wang, J. Z., Wang, L., Wang, Q., Wang, Y. F., Wang, Y. X., Wong, H. T., Wu, Y. C., Xing, H. Y., Xiong, K. Z., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, P., Zhang, Z. H., Zhang, Z. Y., Zhao, J. Z., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

We present the first limit on $g_{A\gamma}$ coupling constant using the Bragg-Primakoff conversion based on an exposure of 1107.5 kg days of data from the CDEX-1B experiment at the China Jinping Underground Laboratory. The data are consistent with the null signal hypothesis, and no excess signals are observed. Limits of the coupling $g_{A\gamma}<2.08\times10^{-9}$ GeV$^{-1}$ (95\% C.L.) are derived for axions with mass up to 100 eV/$c^2$. Within the hadronic model of KSVZ, our results exclude axion mass $>5.3~\rm{eV}/c^2$ at 95\% C.L., Comment: 7 pages, 5 figures

Published
2024

2. First Search for Light Fermionic Dark Matter Absorption on Electrons Using Germanium Detector in CDEX-10 Experiment

Author

Liu, J. X., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, Q. J., Guo, T., Guo, X. Y., He, L., He, J. R., Hu, J. W., Huang, H. X., Huang, T. C., Jiang, L., Karmakar, S., Li, H. B., Li, H. Y., Li, J. M., Li, J., Li, M. C., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Ma, H., Mao, Y. C., Nie, Q. Y., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Shen, M. B., Singh, M. K., Sun, T. X., Sun, W. L., Tang, C. J., Tian, Y., Wang, G. F., Wang, J. Z., Wang, L., Wang, Q., Wang, Y. F., Wang, Y. X., Wong, H. T., Wu, Y. C., Xing, H. Y., Xiong, K. Z., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, P., Zhang, Z. H., Zhang, Z. Y., Zhao, J. Z., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

We present the first results of the search for sub-MeV fermionic dark matter absorbed by electron targets of Germanium using the 205.4~kg$\cdot$day data collected by the CDEX-10 experiment, with the analysis threshold of 160~eVee. No significant dark matter (DM) signals over the background are observed. Results are presented as limits on the cross section of DM--electron interaction. We present new constraints of cross section in the DM range of 0.1--10 keV/$c^2$ for vector and axial-vector interaction. The upper limit on the cross section is set to be $\rm 5.5\times10^{-46}~cm^2$ for vector interaction, and $\rm 1.8\times10^{-46}~cm^2$ for axial-vector interaction at DM mass of 5 keV/$c^2$., Comment: 6 pages, 4 figures

Published
2024

3. Constraints on the Blazar-Boosted Dark Matter from the CDEX-10 Experiment

Author

Xu, R., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, Q. J., Guo, T., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jiang, L., Karmakar, S., Li, H. B., Li, H. Y., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, J. X., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Singh, M. K., Sun, T. X., Tang, C. J., Tian, Y., Wang, G. F., Wang, J. Z., Wang, L., Wang, Q., Wang, Y. F., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhang, Z. Y., Zhao, J. Z., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

We report new constraints on light dark matter (DM) boosted by blazars using the 205.4 kg day data from the CDEX-10 experiment located at the China Jinping Underground Laboratory. Two representative blazars, TXS 0506+56 and BL Lacertae are studied. The results derived from TXS 0506+56 exclude DM-nucleon elastic scattering cross sections from $4.6\times 10^{-33}\ \rm cm^2$ to $1\times10^{-26}\ \rm cm^2$ for DM masses between 10 keV and 1 GeV, and the results derived from BL Lacertae exclude DM-nucleon elastic scattering cross sections from $2.4\times 10^{-34}\ \rm cm^2$ to $1\times10^{-26}\ \rm cm^2$ for the same range of DM masses. The constraints correspond to the best sensitivities among solid-state detector experiments in the sub-MeV mass range., Comment: 7 pages, 4 figures

Published
2024

4. Probing Dark Matter Particles from Evaporating Primordial Black Holes via Electron Scattering in the CDEX-10 Experiment

Author

Zhang, Z. H., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, Q. J., Guo, T., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jiang, L., Karmakar, S., Li, H. B., Li, H. Y., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, J. X., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Singh, M. K., Sun, T. X., Tang, C. J., Tian, Y., Wang, G. F., Wang, J. Z., Wang, L., Wang, Q., Wang, Y. F., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. Y., Zhao, J. Z., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

Dark matter (DM) is a major constituent of the Universe. However, no definite evidence of DM particles (denoted as ``$\chi$") has been found in DM direct detection (DD) experiments to date. There is a novel concept of detecting $\chi$ from evaporating primordial black holes (PBHs). We search for $\chi$ emitted from PBHs by investigating their interaction with target electrons. The examined PBH masses range from 1$\times$10$^{15}$ to 7$\times$10$^{16}$ g under the current limits of PBH abundance $f_{PBH}$. Using 205.4 kg$\cdot$day data obtained from the CDEX-10 experiment conducted in the China Jinping Underground Laboratory, we exclude the $\chi$--electron ($\chi$--$e$) elastic-scattering cross section $\sigma_{\chi e} \sim 5\times10^{-29}$ cm$^2$ for $\chi$ with a mass $m_{\chi}\lesssim$ 0.1 keV from our results. With the higher radiation background but lower energy threshold (160 eV), CDEX-10 fill a part of the gap in the previous work. If ($m_{\chi}$, $\sigma_{\chi e}$) can be determined in the future, DD experiments are expected to impose strong constraints on $f_{PBH}$ for large $M_{PBH}$s., Comment: 9 pages, 6 figures, 3 tables. Version updated to match SCPMA version

Published
2024
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5. Experimental Limits on Solar Reflected Dark Matter with a New Approach on Accelerated-Dark-Matter-Electron Analysis in Semiconductors

Author

Zhang, Z. Y., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, Q. J., Guo, T., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jiang, L., Karmakar, S., Li, H. B., Li, H. Y., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, J. X., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Singh, M. K., Sun, T. X., Tang, C. J., Tian, Y., Wang, G. F., Wang, J. Z., Wang, L., Wang, Q., Wang, Y. F., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhao, J. Z., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

Recently a dark matter-electron (DM-electron) paradigm has drawn much attention. Models beyond the standard halo model describing DM accelerated by high energy celestial bodies are under intense examination as well. In this Letter, a velocity components analysis (VCA) method dedicated to swift analysis of accelerated DM-electron interactions via semiconductor detectors is proposed and the first HPGe detector-based accelerated DM-electron analysis is realized. Utilizing the method, the first germanium based constraint on sub-GeV solar reflected DM-electron interaction is presented with the 205.4 kg$\cdot$day dataset from the CDEX-10 experiment. In the heavy mediator scenario, our result excels in the mass range of 5$-$15 keV/$c^2$, achieving a 3 orders of magnitude improvement comparing with previous semiconductor experiments. In the light mediator scenario, the strongest laboratory constraint for DM lighter than 0.1 MeV/$c^2$ is presented. The result proves the feasibility and demonstrates the vast potential of the VCA technique in future accelerated DM-electron analyses with semiconductor detectors., Comment: 7 pages, 4 figures. Version updated to match PRL version

Published
2023
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6. Projected WIMP sensitivity of the CDEX-50 dark matter experiment

Author

Geng, X. P., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Gong, H., Guo, Q. J., Guo, T., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jiang, L., Karmakar, S., Li, H. B., Li, H. Y., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, J. X., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Singh, M. K., Sun, T. X., Tang, C. J., Tian, Y., Wang, G. F., Wang, J. Z., Wang, L., Wang, Q., Wang, Y. F., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhang, Z. Y., Zhao, J. Z., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

CDEX-50 is a next-generation project of the China Dark Matter Experiment (CDEX) that aims to search for dark matter using a 50-kg germanium detector array. This paper comprises a thorough summary of the CDEX-50 dark matter experiment, including an investigation of potential background sources and the development of a background model. Based on the baseline model, the projected sensitivity of weakly interacting massive particle (WIMP) is also presented. The expected background level within the energy region of interest, set to 2--2.5 keVee, is $\sim$0.01 counts keVee$^{-1}$ kg$^{-1}$ day$^{-1}$. At 90\% confidence level, the expected sensitivity to spin-independent WIMP-nucleon couplings is estimated to reach a cross-section of 5.1 $\times$ 10$^{-45}$ cm$^{2}$ for a WIMP mass of 5 GeV/c$^{2}$ with an exposure objective of 150 kg$\cdot$year and an analysis threshold of 160 eVee. This science goal will correspond to the most sensitive results for WIMPs with a mass of 2.2--8 GeV/c$^{2}$., Comment: 12 pages, 11 figures. Version updated to match JCAP version

Published
2023
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7. Searching for $^{76}$Ge neutrinoless double beta decay with the CDEX-1B experiment

Author

Zhang, B. T., Wang, J. Z., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, Q. J., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jia, H. T., Jiang, X., Karmakar, S., Li, H. B., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, J. X., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Liu, Z. Z., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., She, Z., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y. F., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhang, Z. Y., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

We operated a p-type point contact high purity germanium (PPCGe) detector (CDEX-1B, 1.008 kg) in the China Jinping Underground Laboratory (CJPL) for 500.3 days to search for neutrinoless double beta ($0\nu\beta\beta$) decay of $^{76}$Ge. A total of 504.3 kg$\cdot$day effective exposure data was accumulated. The anti-coincidence and the multi/single-site event (MSE/SSE) discrimination methods were used to suppress the background in the energy region of interest (ROI, 1989$-$2089 keV for this work) with a factor of 23. A background level of 0.33 counts/(keV$\cdot$kg$\cdot$yr) was realized. The lower limit on the half life of $^{76}$Ge $0\nu\beta\beta$ decay was constrained as $T_{1/2}^{0\nu}\ > \ {1.0}\times 10^{23}\ \rm yr\ (90\% \ C.L.)$, corresponding to the upper limits on the effective Majorana neutrino mass: $\langle m_{\beta\beta}\rangle < $3.2$-$7.5$\ \mathrm{eV}$., Comment: 11 pages, 12 figures, 2 tables. Version updated to match CPC version

Published
2023
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8. Search for boosted keV-MeV light dark matter particles from evaporating primordial black holes at the CDEX-10 experiment

Author

Zhang, Z. H., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, Q. J., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jia, H. T., Jiang, X., Karmakar, S., Li, H. B., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, J. X., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Liu, Z. Z., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., She, Z., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y. F., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. Y., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

We present novel constraints on boosted light dark matter particles (denoted as ``$\chi$'') from evaporating primordial black holes (PBHs) using 205.4 kg$\cdot$day data from the China Jinping Underground Laboratory's CDEX-10 p-type point contact germanium detector with a 160 eVee analysis threshold. $\chi$ from PBHs with masses ranging from 1$\times$10$^{15}$ g to 7$\times$10$^{16}$ g are searched in this work. In the presence of PBH abundance compatible with present bounds, our result excludes the $\chi$-nucleon elastic-scattering cross section region from 3.4$\times$10$^{-32}$ cm$^{2}$ to 2.3$\times$10$^{-29}$ cm$^{2}$ for $\chi$ of 1 keV to 24 MeV from PBHs with masses of 5$\times$10$^{15}$ g, as well as from 1.1$\times$10$^{-28}$ cm$^{2}$ to 7.6$\times$10$^{-28}$ cm$^{2}$ for $\chi$ of 1 keV to 0.6 MeV from PBHs with masses of 7$\times$10$^{16}$ g. If the $\chi$-nucleon elastic-scattering cross section can be determined in the future, the abundance of PBHs may be severely constrained by $\chi$ evaporation. With the lower threshold (160 eVee) of the CDEX-10 experiment compared to the previously used experiments, this work allows for a better reach at soft spectra produced by heavier PBHs, which demonstrates the vast potential of such a technical route to pursue $\chi$ from larger PBHs with a low threshold., Comment: 8 pages, 6 figures. Version updated to match PRD version

Published
2022
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9. Search for exotic interactions of solar neutrinos in the CDEX-10 experiment

Author

Geng, X. P., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Gong, H., Guo, Q. J., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jia, H. T., Jiang, X., Karmakar, S., Li, H. B., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, J. X., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Liu, Z. Z., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., She, Z., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y. F., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhang, Z. Y., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

We investigate exotic neutrino interactions using the 205.4 kg$\cdot$day dataset from the CDEX-10 experiment at the China Jinping Underground Laboratory. New constraints on the mass and couplings of new gauge bosons are presented. Two nonstandard neutrino interactions are considered: a $U(1)_{B-L}$ gauge-boson-induced interaction between an active neutrino and electron/nucleus, and a dark-photon-induced interaction between a sterile neutrino and electron/nucleus via kinetic mixing with a photon. This work probes an unexplored parameter space involving sterile neutrino coupling with a dark photon. New laboratory limits are derived on dark photon masses below $1~{\rm eV}/c^{2}$ at some benchmark values of $\Delta m_{41}^{2}$ and $g^{\prime2}{\rm{sin}}^{2}2\theta_{14}$., Comment: 6 pages, 4 figures. Version updated to match PRD version

Published
2022
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10. Exotic Dark Matter Search with CDEX-10 Experiment at China's Jinping Underground Laboratory

Author

Dai, W. H., Jia, L. P., Ma, H., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, Q. J., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jia, H. T., Jiang, X., Karmakar, S., Li, H. B., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Liu, Z. Z., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., She, Z., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yang, L. T., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhang, Z. Y., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

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 ($\chi+A\rightarrow \nu+A$) and DM-nucleus 3$\rightarrow$2 scattering ($\chi+\chi+A\rightarrow \phi+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 region. A cross section limit for the fermionic DM absorption is set to be $\rm 2.5\times 10^{-46} cm^2$(90\% C.L.) at DM mass of 10 MeV/c$^2$. For the DM-nucleus 3$\rightarrow$2 scattering scenario, limits are extended to DM mass of 5 MeV/c$^2$ and 14 MeV/c$^2$ for the massless dark photon and bound DM final state, respectively., Comment: 5 pages, 7 figures

Published
2022
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11. Constraints on Sub-GeV Dark Matter--Electron Scattering from the CDEX-10 Experiment

Author

Zhang, Z. Y., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., Agartioglu, M., An, H. P., Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, Q. J., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jia, H. T., Jiang, X., Li, H. B., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Liu, Z. Z., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Saraswat, K., Sharma, V., She, Z., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yeh, C. H., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

We present improved germanium-based constraints on sub-GeV dark matter via dark matter--electron ($\chi$-$e$) scattering using the 205.4 kg$\cdot$day dataset from the CDEX-10 experiment. Using a novel calculation technique, we attain predicted $\chi$-$e$ scattering spectra observable in high-purity germanium detectors. In the heavy mediator scenario, our results achieve 3 orders of magnitude of improvement for $m_{\chi}$ larger than 80 MeV/c$^2$ compared to previous germanium-based $\chi$-$e$ results. We also present the most stringent $\chi$-$e$ cross-section limit to date among experiments using solid-state detectors for $m_{\chi}$ larger than 90 MeV/c$^2$ with heavy mediators and $m_{\chi}$ larger than 100 MeV/c$^2$ with electric dipole coupling. The result proves the feasibility and demonstrates the vast potential of a new $\chi$-$e$ detection method with high-purity germanium detectors in ultralow radioactive background., Comment: 6 pages, 3 figures. Version updated to match PRL version

Published
2022
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12. Search for Neutrinoless Double-Beta Decay of $^{76}$Ge with a Natural Broad Energy Germanium Detector

Author

CDEX collaboration, Dai, W. H., Ma, H., Yue, Q., She, Z., Kang, K. J., Li, Y. J., Agartioglu, M., An, H. P., Chang, J. P., Chen, Y. H., Cheng, J. P., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, Q. J., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jia, H. T., Jiang, X., Li, H. B., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Liu, Z. Z., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Saraswat, K., Sharma, V., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yang, L. T., Yeh, C. H., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhang, Z. Y., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

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{$\nu\beta\beta$}) 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 kg$\cdot$day, thus a limit on the half life of $^{76}$Ge 0$\nu\beta\beta$ decay is set at T$_{1/2}^{0\nu}$ $>$ 5.62$\times$10$^{22}$ yr at 90% C.L.. The limit corresponds to an effective Majorana neutrino mass in the range of 4.6 $\sim$ 10.3 eV, dependent on the nuclear matrix elements., Comment: 10 pages, 15 figures

Published
2022
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13. Constraints on sub-GeV dark matter boosted by cosmic rays from the CDEX-10 experiment at the China Jinping Underground Laboratory

Author

Xu, R., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., Agartioglu, M., An, H. P., Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, X. Y., Guo, Q. J., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jia, H. T., Jiang, X., Li, H. B., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, S. K., Liu, Y., Liu, Y. D., Liu, Y. Y., Liu, Z. Z., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Saraswat, K., Sharma, V., She, Z., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, Y., Xue, T., Yan, Y. L., Yeh, C. H., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhang, Z. Y., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

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 scattering cross-section region from $1.7\times 10^{-30}$ to $10^{-26}~\rm cm^2$ for dark matter of 10 keV$/c^2$ to 1 GeV$/c^2$., Comment: 9 pages, 7 figures. Version updated to match PRD version

Published
2022
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15. Studies of the Earth shielding effect to direct dark matter searches at the China Jinping Underground Laboratory

Author

Liu, Z. Z., Yang, L. T., Yue, Q., Yeh, C. H., Kang, K. J., Li, Y. J., Agartioglu, M., An, H. P., Chang, J. P., Chen, J. H., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, X. Y., Guo, Q. J., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jia, H. T., Jiang, X., Li, H. B., Li, J. M., Li, J., Li, R. M. J., Li, X. Q., Li, Y. L., Liao, B., Lin, F. K., Lin, S. T., Liu, S. K., Liu, Y., Liu, Y. D., Liu, Y. Y., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Saraswat, K., Sharma, V., She, Z., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y., Wang, Y. X., Wang, Z., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, Z. H., Zhang, Z. Y., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

Dark matter direct detection experiments mostly operate at deep underground laboratories. It is necessary to consider shielding effect of the Earth, especially for dark matter particles interacting with a large cross section. We analyzed and simulated the Earth shielding effect for dark matter at the China Jinping Underground Laboratory (CJPL) with a simulation package, CJPL Earth Shielding Simulation code (CJPL\_ESS), which is applicable to other underground locations. The further constraints on the $\chi$-N cross section exclusion regions are derived based on the studies with CDEX experiment data., Comment: 8 pages, 8 figures, 2 tables. Version updated to match PRD version

Published
2021
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16. First experimental constraints on WIMP couplings in the effective field theory framework from CDEX

Author

Wang, Y., Zeng, Z., Yue, Q., Yang, L. T., Kang, K. J., Li, Y. J., Agartioglu, M., An, H. P., Chang, J. P., Chen, J. H., Chen, Y. H., Cheng, J. P., Chiang, C. Y., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, Q. J., Guo, X. Y., He, H. J., He, L., He, S. M., Hu, J. W., Huang, T. C., Huang, H. X., Jia, H. T., Jia, L. P., Jiang, X., Li, H. B., Li, J. M., Li, J., Li, M. X., Li, R. M. J., Li, X., Li, Y. L., Liao, B., Lin, F. K., Lin, S. T., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Liu, Z. Z., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Shang, C. S., Sharma, V., She, Z., Singh, L., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y. C., Wang, Y. X., Wang, Z., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zhang, B. T., Zhang, L., Zhang, F. S., Zhang, Z. Y., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

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 $m_{\chi}$ region. In the chiral effective field theory approach, data from CDEX-10 were used to set an upper limit on WIMP-pion coupling at 90% C.L. We for the first time extended the limit to the $m_{\chi}<$ 6 GeV/$c^2$ region., Comment: version accepted by Science China-PMA, 8 pages, 8 figures

Published
2020
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18. Strong Light Confinement in Rod-Connected Diamond Photonic Crystals

Author

Taverne, M. P. C., Ho, Y. -L. D., Zheng, X., Chen, L. -F., Fang, C. -H. N., and Rarity, J. G.

Subjects
Physics - Optics
Abstract

We show that it is possible to confine light in a volume of order 10^-3 cubic wavelengths using only dielectric material. Low-index (air) cavities are simulated in high index rod-connected diamond (RCD) photonic crystals. These cavities show long storage times (Q-factors >10^6) even at the lowest volumes. Fabrication of such structures could open up a new field of photon level interactions., Comment: 4 pages, 5 figures

Published
2018
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19. Development and validation of a nomogram and risk stratification system to predict overall survival after surgical repair for pediatric patients with medulloblastoma based on easily accessible variables.

Author

FANG, C.-H., WEN, C., YANG, B., SONG, Y.-H., LIU, H.-Q., TIAN, L., CHEN, H., and BAO, N.

Abstract

OBJECTIVE: This study aimed to develop and validate a nomogram and risk stratification system for the overall survival of pediatric patients with medulloblastoma after surgical repair. PATIENTS AND METHODS: In this multicenter, retrospective study, consecutive patients who underwent surgery for medulloblastoma at Shanghai Children's Medical Center and the First Affiliated Hospital of Fujian Medical University from 2010 to 2022 formed the training and external validation datasets, respectively. Univariable and multivariable Cox regression analyses were performed to identify variables associated with mortality in the training dataset. A nomogram prediction model was developed based on independent variables in the multivariable Cox regression analysis to predict the 1-, 3-, and 5-year overall survival. The area under receiver operating characteristic curve (AUC) and calibration curve were used to evaluate the discrimination and calibration of the nomogram. A risk stratification system based on the median risk score was also established to divide patients into two risk groups. RESULTS: In the training dataset, Cox regression analyses identified tumor size, brainstem involvement and chemotherapy as independent predictors for overall survival. The AUC of the nomogram was 0.75 at 1 year, 0. 75 at 3 years, 0.77 at 5 years in the training dataset, 0.74 at 1 year, 0.70 at 3 years, and 0.70 at 5 years in the validation dataset. The calibration curve for the probability of 1-, 3-, and 5-year survival showed good agreement between the nomogram prediction and actual observation in the training and validation datasets. The risk stratification system could perfectly classify patients into two risk groups, and the overall survival in the two groups had a good division. CONCLUSIONS: This low-cost, convenient, and noninvasive nomogram can be translated into clinical practice as a tool for risk stratification and individualized prognosis prediction for children with medulloblastoma. [ABSTRACT FROM AUTHOR]

Published
2024

20. Projected sensitivity of the CDEX-50 experiment

Author

Geng, X. P., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Gong, H., Guo, Q. J., Guo, T., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jiang, L., Karmakar, S., Li, H. B., Li, H. Y., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, J. X., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Singh, M. K., Sun, T. X., Tang, C. J., Tian, Y., Wang, G. F., Wang, J. Z., Wang, L., Wang, Q., Wang, Y. F., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhang, Z. Y., Zhao, J. Z., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., Zhu, J. J., Geng, X. P., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Gong, H., Guo, Q. J., Guo, T., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jiang, L., Karmakar, S., Li, H. B., Li, H. Y., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, J. X., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Singh, M. K., Sun, T. X., Tang, C. J., Tian, Y., Wang, G. F., Wang, J. Z., Wang, L., Wang, Q., Wang, Y. F., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhang, Z. Y., Zhao, J. Z., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Abstract

CDEX-50 is a next-generation project of the China Dark Matter Experiment (CDEX) that aims to search for dark matter using a 50-kg germanium detector array. This paper comprises a thorough summary of the CDEX-50 experiment, including an investigation of potential background sources and the development of a background model. Based on the baseline model, the projected sensitivity of weakly interacting massive particle (WIMP) is also presented. The expected background level within the energy region of interest, set to 2--2.5 keVee, is $\sim$0.01 counts keVee$^{-1}$ kg$^{-1}$ day$^{-1}$. At 90\% confidence level, the expected sensitivity to spin-independent WIMP-nucleon couplings is estimated to reach a cross-section of 5.3 $\times$ 10$^{-45}$ cm$^{2}$ for a WIMP mass of 5 GeV/c$^{2}$ with an exposure objective of 150 kg$\cdot$year and an analysis threshold of 160 eVee. This science goal will correspond to the most sensitive results for WIMPs with a mass of 2.2--8 GeV/c$^{2}$., Comment: 11 pages, 11 figures

Published
2023

21. Structure of Aqueous Cs2CO3 Solution by X-ray Scattering.

Author

Zhang, W. Q., Han, L., Zhou, Y. Q., Fang, C. H., Li, W., Zhu, F. Y., Liu, H. Y., Zhang, Y. Y., Liu, Y. J., Xiao, M. X., Guo, X. Y., Bao, K., Zhao, Y. L., and Han, X. C.

Abstract

The micro-structure parameters of Cs2CO3 solution (salt/water molar ratios are 1 : 15, 1 : 35, 1 : 50) at 323, 298, 273, and 248 K were obtained by model calculation with X' Pert Pro X-ray diffractometer. The obtained average Cs–O distance is 0.323 nm, and the corresponding coordination number is ~5.17. Interaction distance of Cs–C() is 0.318 nm, coordination number varies with the concentration. Molar ratio of 1:15 solution is nearly saturated, and there is a bigger probability to form contact ion pairs (Cs– ) with the coordination number 0.89 in average; the number of 1 : 35 is ~0.31, and the 1 : 50 samples are guaranteed to be fully hydrated with less contact ion pairs, resulting in an average coordination number of 0.03. Three different molar ratios represent three microstates of inside solutions, so there are differences in the microstructure parameters among samples. The coordination distance of O–O–(H-bonding) is ~0.275 nm and the coordination number is ~2.23. The interaction distance of C()–OH2 is ~0.374 nm and the number of the interaction is ~7.28. The carbonate ion as well as cesium ion exists in a hydrated cluster in the solution, and partly forming contact ions with each other. The interaction between oxygen atoms in and water molecules around is similar to the hydrogen bonds. In addition, it can be concluded that the parameters of intra-molecular interactions (O–H(H2O), C–O(), O–O()) change little with the changing temperature and concentration according to the model calculation results. For inter-molecular interactions (Cs–O(H2O), Cs–O(II), O–O(H-bonding)), the changing of coordination distances and numbers is obvious with temperature and concentration. [ABSTRACT FROM AUTHOR]

Published
2023
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23. Constraints on sub-GeV Dark Matter Boosted by Cosmic Rays from CDEX-10 Experiment at the China Jinping Underground Laboratory

Author

Xu, R., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., Agartioglu, M., An, H. P., Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, X. Y., Guo, Q. J., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jia, H. T., Jiang, X., Li, H. B., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, S. K., Liu, Y., Liu, Y. D., Liu, Y. Y., Liu, Z. Z., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Saraswat, K., Sharma, V., She, Z., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, Y., Xue, T., Yan, Y. L., Yeh, C. H., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhang, Z. Y., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., Zhu, J. J., Xu, R., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., Agartioglu, M., An, H. P., Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, X. Y., Guo, Q. J., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jia, H. T., Jiang, X., Li, H. B., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, S. K., Liu, Y., Liu, Y. D., Liu, Y. Y., Liu, Z. Z., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Saraswat, K., Sharma, V., She, Z., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, Y., Xue, T., Yan, Y. L., Yeh, C. H., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. H., Zhang, Z. Y., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Abstract

We present new constraints on light dark matter boosted by cosmic rays (CRs) 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 scattering cross-section region from $1.7\times 10^{-30}~\rm cm^2$ to $10^{-26}~\rm cm^2$ for dark matter of 10 keV$/c^2$ to 1 GeV$/c^2$., Comment: 9 pages, 7 figures. Added discussion of CR inputs and parameter choices

Published
2022

25. Studies of the Earth shielding effect to direct dark matter searches at the China Jinping Underground Laboratory

Author

Liu, Z. Z., Yang, L. T., Yue, Q., Yeh, C. H., Kang, K. J., Li, Y. J., Agartioglu, M., An, H. P., Chang, J. P., Chen, J. H., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, X. Y., Guo, Q. J., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jia, H. T., Jiang, X., Li, H. B., Li, J. M., Li, J., Li, R. M. J., Li, X. Q., Li, Y. L., Liao, B., Lin, F. K., Lin, S. T., Liu, S. K., Liu, Y., Liu, Y. D., Liu, Y. Y., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., Saraswat, K., Sharma, V., She, Z., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y., Wang, Y. X., Wang, Z., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, Z. H., Zhang, Z. Y., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Phenomenology, High Energy Physics - Experiment (hep-ex), Physics - Instrumentation and Detectors, High Energy Physics - Phenomenology (hep-ph), Physics::Instrumentation and Detectors, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), High Energy Physics - Experiment, Physics::Geophysics
Abstract

Dark matter direct detection experiments mostly operate at deep underground laboratories. It is necessary to consider shielding effect of the Earth, especially for dark matter particles interacting with a large cross section. We analyzed and simulated the Earth shielding effect for dark matter at the China Jinping Underground Laboratory (CJPL) with a simulation package, CJPL Earth Shielding Simulation code (CJPL\_ESS), which is applicable to other underground locations. The further constraints on the $\chi$-N cross section exclusion regions are derived based on the studies with CDEX experiment data., Comment: 8 pages, 8 figures, 2 tables. Version updated to match PRD version

Published
2022
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26. Search for keV--MeV Light Dark Matter from Evaporating Primordial Black Holes at the CDEX-10 Experiment

Author

Zhang, Z. H., Yang, L. T., Yue, Q., Kang, K. J., Li, Y. J., An, H. P., C., Greeshma, Chang, J. P., Chen, Y. H., Cheng, J. P., Dai, W. H., Deng, Z., Fang, C. H., Geng, X. P., Gong, H., Guo, Q. J., Guo, X. Y., He, L., He, S. M., Hu, J. W., Huang, H. X., Huang, T. C., Jia, H. T., Jiang, X., Karmakar, S., Li, H. B., Li, J. M., Li, J., Li, Q. Y., Li, R. M. J., Li, X. Q., Li, Y. L., Liang, Y. F., Liao, B., Lin, F. K., Lin, S. T., Liu, J. X., Liu, S. K., Liu, Y. D., Liu, Y., Liu, Y. Y., Liu, Z. Z., Ma, H., Mao, Y. C., Nie, Q. Y., Ning, J. H., Pan, H., Qi, N. C., Ren, J., Ruan, X. C., She, Z., Singh, M. K., Sun, T. X., Tang, C. J., Tang, W. Y., Tian, Y., Wang, G. F., Wang, L., Wang, Q., Wang, Y. F., Wang, Y. X., Wong, H. T., Wu, S. Y., Wu, Y. C., Xing, H. Y., Xu, R., Xu, Y., Xue, T., Yan, Y. L., Yi, N., Yu, C. X., Yu, H. J., Yue, J. F., Zeng, M., Zeng, Z., Zhang, B. T., Zhang, F. S., Zhang, L., Zhang, Z. Y., Zhao, K. K., Zhao, M. G., Zhou, J. F., Zhou, Z. Y., and Zhu, J. J.

Subjects
High Energy Physics - Phenomenology, High Energy Physics - Experiment (hep-ex), Physics - Instrumentation and Detectors, High Energy Physics - Phenomenology (hep-ph), FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), High Energy Physics - Experiment
Abstract

We present novel constraints on light dark matter (DM) from evaporating primordial black holes (PBHs), using the 205.4 kg$\cdot$day data from China Jinping Underground Laboratory's CDEX-10 p-type point contact germanium detector with 160 eVee analysis threshold. DM from PBHs with masses ranging from 1$\times$10$^{15}$ to 2$\times$10$^{16}$ g is searched in this work. In the presence of PBH abundance compatible with present bounds, our result excludes the DM-nucleon elastic scattering cross section region from 8.2$\times$10$^{-31}$ to 2.0$\times$10$^{-29}$ cm$^{2}$ for DM of 1 keV to 15 MeV from PBHs with masses of 5$\times$10$^{15}$ g, as well as, from 1.7$\times$10$^{-29}$ to 5.0$\times$10$^{-29}$ cm$^{2}$ for DM of 1 keV to 2 MeV from PBHs with masses of 1.8$\times$10$^{16}$ g. If the DM-nucleon elastic scattering cross section can be determined in the future, the abundance of PBH may be severely constrained by DM evaporation., Comment: 7 pages, 6 figures

Published
2022
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34. Application of Spectral Extrapolation Technique to Stepped-Frequency RCS Measurement.

Author

Hu, C. F., Li, N. J., and Fang, C. H.

Subjects
RADAR cross sections, EXTRAPOLATION, AUTOREGRESSIVE models, ALGORITHMS
Abstract

“Time domain gating” used in the steppedfrequency radar cross section (RCS) measurement causes the inaccurate frequency domain data, especially at two ends of the band. This paper proposes a spectral extrapolation method for improving the measured RCS at two ends of the band more exactly. The core idea is: the measured frequency domain data are extrapolated to obtain the unknown value out of band with an autoregressive model (AR model). The parameter in the AR model is calculated by the maximum entropy spectral estimation algorithm. Therefore, the span of the original band is extended, and both ends of frequency on the original band are inside the range of the new band. If the time domain gating is adding to the new band, the precision at two ends of the original band can be greatly improved. The simulation and experimental results show that more effective frequency domain data near the two ends of the band can be predicted by using the spectral extrapolation method, and the maximum error at the ends of the original band is less than 1dB after extrapolation, so it can ensure the accuracy of RCS measurement over the whole frequency band. [ABSTRACT FROM AUTHOR]

Published
2020
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35. Phase field modeling of excimer laser crystallization of thin silicon films on amorphous substrates.

Author

Shih, C. J., Fang, C. H., Lu, C. C., Wang, M. H., Lee, M. H., and Lan, C. W.

Subjects
*EXCIMER lasers, *CRYSTALLIZATION, *AMORPHOUS substances, *SILICON, *THIN films
Abstract

Excimer laser crystallization processing of thin silicon films on amorphous silicon oxide substrates was simulated by means of phase field modeling. The quantitative phase field model was derived from the Gibbs-Thompson equation coupled with energy conservation. Because the adaptive mesh scheme was adopted, the present calculations could accommodate both two-dimensional superlateral growth (SLG) phenomena and the realistic interface thickness (in the order of 10-10 m). The vertical growth of fine-grained nucleation structures was simulated using one-dimensional calculations, and the results are consistent with those obtained in previous experiments. Two cases of SLG were also simulated, and the evolution of the interface and thermal fields was determined. Based on our simulation results, we conclude that SLG crystallization does not achieve steady growth because of the extremely fast heat dissipation from the substrate. To obtain very uniform electric characteristics for device fabrication, the layout design and the device position should take the SLG laser mask into consideration. [ABSTRACT FROM AUTHOR]

Published
2006
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36. DENSIFICATION OF WOOD VENEERS COMBINED WITH OIL-HEAT TREATMENT. PART II: HYGROSCOPICITY AND MECHANICAL PROPERTIES

Author

Fang, C. H., Cloutier, A., Pierre Blanchet, and Koubaa, A.

Subjects
Wood densification, lcsh:Biotechnology, lcsh:TP248.13-248.65, Oil-heat treatment, Aspen, Mechanical properties, Hygroscopicity
Abstract

In an effort to achieve high mechanical performance and improved dimensional stability, densification combined with oil-heat treatment (OHT) was performed. In our previous study, OHT was successfully applied to densified veneer, which resulted in improved dimensional stability. In the present study, the impact of OHT on densified wood veneer hygroscopicity and mechanical properties was determined. OHT at 180, 200, and 220ºC for 1, 2, and 3 hours was applied to densified Aspen (Populus tremuloides) veneers. OHT was found to be an efficient treatment to reduce the hygroscopicity of densified aspen veneers, although OHT had a negative impact on Brinell hardness. However, due to the contribution of densification, the hardness of oil-heat treated veneers was still two to three times higher than that of non-densified veneers. Similar results were found for tensile strength. Bending strength increased slightly at low OHT temperature, and then decreased at high temperature. Bending strength of oil-heat treated densified veneer samples was higher than that of non-densified ones. No significant effect of OHT was found on tensile MOE, but bending MOE increased after OHT. Compared to OHT duration, OHT temperature had a larger impact on densified wood hygroscopicity and mechanical properties.

Published
2012

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