Browsing by Author "J. Li"

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Bulk and surface event identification in p-type germanium detectors
(Elsevier B.V., 2018) L.T. Yang; H.B. Li; H.T. Wong; M. Agartioglu; J.H. Chen; L.P. Jia; H. Jiang; J. Li; F.K. Lin; S.T. Lin; S.K. Liu; J.L. Ma; B. Sevda; V. Sharma; L. Singh; M.K. Singh; M.K. Singh; A.K. Soma; A. Sonay; S.W. Yang; L. Wang; Q. Wang; Q. Yue; W. Zhao
The p-type point-contact germanium detectors have been adopted for light dark matter WIMP searches and the studies of low energy neutrino physics. These detectors exhibit anomalous behavior to events located at the surface layer. The previous spectral shape method to identify these surface events from the bulk signals relies on spectral shape assumptions and the use of external calibration sources. We report an improved method in separating them by taking the ratios among different categories of in situ event samples as calibration sources. Data from CDEX-1 and TEXONO experiments are re-examined using the ratio method. Results are shown to be consistent with the spectral shape method. © 2018 Elsevier B.V.
Characterization and performance of germanium detectors with sub-keV sensitivities for neutrino and dark matter experiments
(Elsevier B.V., 2016) A.K. Soma; M.K. Singh; L. Singh; G. Kiran Kumar; F.K. Lin; Q. Du; H. Jiang; S.K. Liu; J.L. Ma; V. Sharma; L. Wang; Y.C. Wu; L.T. Yang; W. Zhao; M. Agartioglu; G. Asryan; Y.Y. Chang; J.H. Chen; Y.C. Chuang; M. Deniz; C.L. Hsu; Y.H. Hsu; T.R. Huang; L.P. Jia; S. Kerman; H.B. Li; J. Li; F.T. Liao; H.Y. Liao; C.W. Lin; S.T. Lin; V. Marian; X.C. Ruan; B. Sevda; Y.T. Shen; M.K. Singh; V. Singh; A. Sonay; J. Su; V.S. Subrahmanyam; C.H. Tseng; J.J. Wang; H.T. Wong; Y. Xu; S.W. Yang; C.X. Yu; Q. Yue; M. Zeyrek
Germanium ionization detectors with sensitivities as low as 100 eVee (electron-equivalent energy) open new windows for studies on neutrino and dark matter physics. The relevant physics subjects are summarized. The detectors have to measure physics signals whose amplitude is comparable to that of pedestal electronic noise. To fully exploit this new detector technique, various experimental issues including quenching factors, energy reconstruction and calibration, signal triggering and selection as well as evaluation of their associated efficiencies have to be attended. The efforts and results of a research program to address these challenges are presented. © 2016 Elsevier B.V.
Constraints on a noncommutative physics scale with neutrino-electron scattering
(2012) S. Bilmiş; M. Deniz; H.B. Li; J. Li; H.Y. Liao; S.T. Lin; V. Singh; H.T. Wong; A.O. YIldIrIm; Q. Yue; M. Zeyrek
Neutrino-electron scatterings (ν-e) are purely leptonic processes with robust standard model predictions. Their measurements can therefore provide constraints to physics beyond the standard model. Noncommutative (NC) field theories modify space-time commutation relations, and allow neutrino electromagnetic couplings at the tree level. Their contribution to the neutrino-electron scattering cross section was derived. Constraints were placed on the NC scale parameter Λ NC from ν-e experiments with reactor and accelerator neutrinos. The most stringent limit of Λ NC>3.3TeV at 95% confidence level improves over the direct bounds from collider experiments. © 2012 American Physical Society.
Constraints on axion couplings from the CDEX-1 experiment at the China Jinping Underground Laboratory
(American Physical Society, 2017) S.K. Liu; Q. Yue; K.J. Kang; J.P. Cheng; H.T. Wong; Y.J. Li; H.B. Li; S.T. Lin; J.P. Chang; J.H. Chen; N. Chen; Q.H. Chen; Y.H. Chen; Z. Deng; Q. Du; H. Gong; H.J. He; Q.J. He; H.X. Huang; H. Jiang; J.M. Li; J. Li; J. Li; X. Li; X.Q. Li; X.Y. Li; Y.L. Li; F.K. Lin; L.C. Lü; H. Ma; J.L. Ma; S.J. Mao; J.Q. Qin; J. Ren; J. Ren; X.C. Ruan; V. Sharma; M.B. Shen; L. Singh; M.K. Singh; A.K. Soma; J. Su; C.J. Tang; J.M. Wang; L. Wang; Q. Wang; S.Y. Wu; Y.C. Wu; Y.C. Wu; Z.Z. Xianyu; R.Q. Xiao; H.Y. Xing; F.Z. Xu; Y. Xu; X.J. Xu; T. Xue; C.W. Yang; L.T. Yang; S.W. Yang; N. Yi; C.X. Yu; H. Yu; X.Z. Yu; X.H. Zeng; Z. Zeng; L. Zhang; Y.H. Zhang; M.G. Zhao; W. Zhao; Z.Y. Zhou; J.J. Zhu; W.B. Zhu; X.Z. Zhu; Z.H. Zhu
We report the results of searches for solar axions and galactic dark matter axions or axionlike particles with the CDEX-1 experiment at the China Jinping Underground Laboratory, using 335.6 kg days of data from a p-type point-contact germanium detector. The data are compatible with the background model, and no excess signals are observed. Limits of solar axions on the model-independent coupling gAe<2.5×10-11 from Compton, bremsstrahlung, atomic-recombination, and deexcitation channels and gANeff×gAe<6.4×10-17 from a Fe57 M1 transition at 90% confidence level are derived. Within the framework of the Dine-Fischler-Srednicki-Zhitnitskiy and Kim-Shifman-Vainshtein-Zakharov models, our results exclude the axion mass heavier than 0.9 and 177 eV/c2, respectively. The derived constraints for dark matter axions below 1 keV improve over the previous results. © 2017 American Physical Society.
Constraints on nonstandard neutrino interactions and unparticle physics with ν̄e-e- scattering at the Kuo-Sheng nuclear power reactor
(2010) M. Deniz; S. Bilmiş; I.O. Yildirim; H.B. Li; J. Li; H.Y. Liao; C.W. Lin; S.T. Lin; M. Serin; V. Singh; H.T. Wong; S.C. Wu; Q. Yue; M. Zeyrek; Z.Y. Zhou
Neutrino-electron scatterings are purely leptonic processes with robust standard model (SM) predictions. Their measurements can therefore provide constraints to physics beyond SM. The ν̄e-e data taken at the Kuo-Sheng Reactor Neutrino Laboratory were used to probe two scenarios: nonstandard neutrino interactions (NSI) and unparticle physics. New constraints were placed on the NSI parameters (εeeeL,εeeeR), (εeμeL,εeμeR), and (εeτeL,εeτeR) for the nonuniversal and flavor-changing channels, respectively, as well as to the coupling constants for scalar (λ0) and vector (λ1) unparticles to the neutrinos and electrons. © 2010 The American Physical Society.
Constraints on Spin-Independent Nucleus Scattering with sub-GeV Weakly Interacting Massive Particle Dark Matter from the CDEX-1B Experiment at the China Jinping Underground Laboratory
(American Physical Society, 2019) Z.Z. Liu; Q. Yue; L.T. Yang; K.J. Kang; Y.J. Li; H.T. Wong; M. Agartioglu; H.P. An; J.P. Chang; J.H. Chen; Y.H. Chen; J.P. Cheng; Z. Deng; Q. Du; H. Gong; X.Y. Guo; Q.J. Guo; L. He; S.M. He; J.W. Hu; Q.D. Hu; H.X. Huang; L.P. Jia; H. Jiang; 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; H. Ma; J.L. Ma; Y.C. Mao; J.H. Ning; H. Pan; N.C. Qi; J. Ren; X.C. Ruan; V. Sharma; Z. She; L. Singh; M.K. Singh; T.X. Sun; C.J. Tang; W.Y. Tang; Y. Tian; G.F. Wang; L. Wang; Q. Wang; Y. Wang; Y.X. Wang; S.Y. Wu; Y.C. Wu; H.Y. Xing; Y. Xu; T. Xue; N. Yi; C.X. Yu; H.J. Yu; J.F. Yue; M. Zeng; Z. Zeng; F.S. Zhang; M.G. Zhao; J.F. Zhou; Z.Y. Zhou; J.J. Zhu
We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (mχ) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in mχ are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σχNSI at 90% confidence level are derived as 2×10-32∼7×10-35 cm2 for TI analysis at mχ∼50-180 MeV/c2, and 3×10-32∼9×10-38 cm2 for AM analysis at mχ∼75 MeV/c2-3.0 GeV/c2. .
Constraints on sub-GeV dark matter boosted by cosmic rays from the CDEX-10 experiment at the China Jinping Underground Laboratory
(American Physical Society, 2022) R. Xu; L.T. Yang; Q. Yue; K.J. Kang; Y.J. Li; M. Agartioglu; H.P. An; J.P. Chang; Y.H. Chen; J.P. Cheng; W.H. Dai; Z. Deng; C.H. Fang; X.P. Geng; H. Gong; X.Y. Guo; Q.J. Guo; L. He; S.M. He; J.W. Hu; H.X. Huang; T.C. Huang; H.T. Jia; X. Jiang; H.B. Li; J.M. Li; J. Li; Q.Y. Li; R.M.J. Li; X.Q. Li; Y.L. Li; Y.F. Liang; B. Liao; F.K. Lin; S.T. Lin; S.K. Liu; Y. Liu; Y.D. Liu; Y.Y. Liu; Z.Z. Liu; H. Ma; Y.C. Mao; Q.Y. Nie; J.H. Ning; H. Pan; N.C. Qi; J. Ren; X.C. Ruan; K. Saraswat; V. Sharma; Z. She; M.K. Singh; T.X. Sun; C.J. Tang; W.Y. Tang; Y. Tian; G.F. Wang; L. Wang; Q. Wang; Y. Wang; Y.X. Wang; H.T. Wong; S.Y. Wu; Y.C. Wu; H.Y. Xing; Y. Xu; T. Xue; Y.L. Yan; C.H. Yeh; N. Yi; C.X. Yu; H.J. Yu; J.F. Yue; M. Zeng; Z. Zeng; B.T. Zhang; F.S. Zhang; L. Zhang; Z.H. Zhang; Z.Y. Zhang; K.K. Zhao; M.G. Zhao; J.F. Zhou; Z.Y. Zhou; J.J. Zhu
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 1.7×10-30 to 10-26 cm2 for dark matter of 10 keV/c2 to 1 GeV/c2. © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.
Constraints on Sub-GeV Dark Matter-Electron Scattering from the CDEX-10 Experiment
(American Physical Society, 2022) Z.Y. Zhang; L.T. Yang; Q. Yue; K.J. Kang; Y.J. Li; M. Agartioglu; H.P. An; J.P. Chang; Y.H. Chen; J.P. Cheng; W.H. Dai; Z. Deng; C.H. Fang; X.P. Geng; H. Gong; Q.J. Guo; X.Y. Guo; L. He; S.M. He; J.W. Hu; H.X. Huang; T.C. Huang; H.T. Jia; X. Jiang; H.B. Li; J.M. Li; J. Li; Q.Y. Li; R.M.J. Li; X.Q. Li; Y.L. Li; Y.F. Liang; B. Liao; F.K. Lin; S.T. Lin; S.K. Liu; Y.D. Liu; Y. Liu; Y.Y. Liu; Z.Z. Liu; H. Ma; Y.C. Mao; Q.Y. Nie; J.H. Ning; H. Pan; N.C. Qi; J. Ren; X.C. Ruan; K. Saraswat; V. Sharma; Z. She; M.K. Singh; T.X. Sun; C.J. Tang; W.Y. Tang; Y. Tian; G.F. Wang; L. Wang; Q. Wang; Y. Wang; Y.X. Wang; H.T. Wong; S.Y. Wu; Y.C. Wu; H.Y. Xing; R. Xu; Y. Xu; T. Xue; Y.L. Yan; C.H. Yeh; N. Yi; C.X. Yu; H.J. Yu; J.F. Yue; M. Zeng; Z. Zeng; B.T. Zhang; F.S. Zhang; L. Zhang; Z.H. Zhang; K.K. Zhao; M.G. Zhao; J.F. Zhou; Z.Y. Zhou; J.J. Zhu
We present improved germanium-based constraints on sub-GeV dark matter via dark matter-electron (?-e) scattering using the 205.4 kg·day dataset from the CDEX-10 experiment. Using a novel calculation technique, we attain predicted ?-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? larger than 80 MeV/c2 compared to previous germanium-based ?-e results. We also present the most stringent ?-e cross-section limit to date among experiments using solid-state detectors for m? larger than 90 MeV/c2 with heavy mediators and m? larger than 100 MeV/c2 with electric dipole coupling. The result proves the feasibility and demonstrates the vast potential of a new ?-e detection method with high-purity germanium detectors in ultralow radioactive background. © 2022 authors. Published by the American Physical Society.
Design and performance of a hybrid fast and thermal neutron detector
(Elsevier B.V., 2017) M.K. Singh; A. Sonay; M. Deniz; M. Ağartıoğlu; G. Asryan; G. Kiran Kumar; H.B. Li; J. Li; F.K. Lin; S.T. Lin; V. Sharma; L. Singh; V. Singh; V.S. Subrahmanyam; A.K. Soma; H.T. Wong; S.W. Yang; I.O. Yıldırım; Q. Yue; M. Zeyrek
We report the characterization, calibration and performance of a custom-built hybrid detector consisting of BC501A liquid scintillator and BC702 scintillator for the detection of fast and thermal neutrons, respectively. Pulse Shape Discrimination techniques are developed to distinguish events due to γ-rays, fast and thermal neutrons. Software analysis packages are developed to derive raw neutron energy spectra from measured proton recoil spectra. The validity is demonstrated through the reconstruction of the 241AmBe(α,n) neutron spectrum. © 2017 Elsevier B.V.
Differentiation of bulk and surface events in p-type point-contact germanium detectors for light WIMP searches
(Elsevier, 2014) H.B. Li; L. Singh; M.K. Singh; A.K. Soma; C.H. Tseng; S.W. Yang; M. Agartioglu; G. Asryan; Y.C. Chuang; M. Deniz; T.R. Huang; G. Kiran Kumar; J. Li; H.Y. Liao; F.K. Lin; S.T. Lin; S.K. Liu; V. Sharma; Y.T. Shen; V. Singh; H.T. Wong; Y.C. Wu; Y. Xu; C.X. Yu; Q. Yue; W. Zhao
The p-type point-contact germanium detectors are novel techniques offering kg-scale radiation sensors with sub-keV sensitivities. They have been used for light dark matter WIMPs searches and may have potential applications in neutrino physics. There are, however, anomalous surface behaviour which needs to be characterized and understood. We describe the methods and results of a research program whose goals are to identify the bulk and surface events via software pulse shape analysis techniques, and to devise calibration schemes to evaluate the selection efficiency factors. Efficiencies-corrected background spectra from the low-background facility at Kuo-Sheng Neutrino Laboratory are derived. © 2014 Elsevier B.V. All rights reserved.
Direct Detection Constraints on Dark Photons with the CDEX-10 Experiment at the China Jinping Underground Laboratory
(American Physical Society, 2020) Z. She; L.P. Jia; Q. Yue; H. Ma; K.J. Kang; Y.J. Li; M. Agartioglu; H.P. An; J.P. Chang; J.H. Chen; Y.H. Chen; J.P. Cheng; W.H. Dai; Z. Deng; X.P. Geng; H. Gong; P. Gu; Q.J. Guo; X.Y. Guo; L. He; S.M. He; H.T. He; J.W. Hu; T.C. Huang; H.X. Huang; H.B. Li; H. Li; J.M. Li; J. Li; M.X. 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; Y.C. Mao; Q.Y. Nie; J.H. Ning; H. Pan; N.C. Qi; C.K. Qiao; J. Ren; X.C. Ruan; B. Sevda; C.S. Shang; V. Sharma; L. Singh; M.K. Singh; T.X. Sun; C.J. Tang; W.Y. Tang; Y. Tian; G.F. Wang; L. Wang; Q. Wang; Y. Wang; Y.X. Wang; Z. Wang; H.T. Wong; S.Y. Wu; H.Y. Xing; Y. Xu; T. Xue; Y.L. Yan; L.T. Yang; N. Yi; C.X. Yu; H.J. Yu; J.F. Yue; M. Zeng; Z. Zeng; B.T. Zhang; L. Zhang; F.S. Zhang; Z.Y. Zhang; M.G. Zhao; J.F. Zhou; Z.Y. Zhou; J.J. Zhu
We report constraints on the dark photon effective kinetic mixing parameter (κ) with data taken from two p-type point-contact germanium detectors of the CDEX-10 experiment at the China Jinping Underground Laboratory. The 90% confidence level upper limits on κ of solar dark photon from 205.4 kg-day exposure are derived, probing new parameter space with masses (mV) from 10 to 300 eV/c2 in direct detection experiments. Considering dark photon as the cosmological dark matter, limits at 90% confidence level with mV from 0.1 to 4.0 keV/c2 are set from 449.6 kg-day data, with a minimum of κ=1.3×10-15 at mV=200 eV/c2. © 2020 authors. Published by the American Physical Society.
Exotic Dark Matter Search with the CDEX-10 Experiment at China's Jinping Underground Laboratory
(American Physical Society, 2022) W.H. Dai; L.P. Jia; H. Ma; Q. Yue; K.J. Kang; Y.J. Li; H.P. An; C. Greeshma; J.P. Chang; Y.H. Chen; J.P. Cheng; Z. Deng; C.H. Fang; X.P. Geng; H. Gong; Q.J. Guo; X.Y. Guo; L. He; S.M. He; J.W. Hu; H.X. Huang; T.C. Huang; H.T. Jia; X. Jiang; S. Karmakar; H.B. Li; J.M. Li; J. Li; Q.Y. Li; R.M.J. Li; X.Q. Li; Y.L. Li; Y.F. Liang; B. Liao; F.K. Lin; S.T. Lin; S.K. Liu; Y.D. Liu; Y. Liu; Y.Y. Liu; Z.Z. Liu; Y.C. Mao; Q.Y. Nie; J.H. Ning; H. Pan; N.C. Qi; J. Ren; X.C. Ruan; Z. She; M.K. Singh; T.X. Sun; C.J. Tang; W.Y. Tang; Y. Tian; G.F. Wang; L. Wang; Q. Wang; Y. Wang; Y.X. Wang; H.T. Wong; S.Y. Wu; Y.C. Wu; H.Y. Xing; R. Xu; Y. Xu; T. Xue; Y.L. Yan; L.T. Yang; N. Yi; C.X. Yu; H.J. Yu; J.F. Yue; M. Zeng; Z. Zeng; B.T. Zhang; F.S. Zhang; L. Zhang; Z.H. Zhang; Z.Y. Zhang; K.K. Zhao; M.G. Zhao; J.F. Zhou; Z.Y. Zhou; J.J. Zhu
A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg day data taken from a p-type point contact germanium detector of the CDEX-10 experiment at China's Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption (?+A+A) and DM-nucleus 3?2 scattering (?+?+A+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 the sub-GeV DM mass region. A cross section limit for the fermionic DM absorption is set to be 2.5×10-46 cm2 (90% C.L.) at DM mass of 10 MeV/c2. For the DM-nucleus 3?2 scattering scenario, limits are extended to DM mass of 5 and 14 MeV/c2 for the massless dark photon and bound DM final state, respectively. © 2022 authors. Published by the American Physical Society.
Experimental Limits on Solar Reflected Dark Matter with a New Approach on Accelerated-Dark-Matter-Electron Analysis in Semiconductors
(American Physical Society, 2024) Z.Y. Zhang; L.T. Yang; Q. Yue; K.J. Kang; Y.J. Li; H.P. An; C. Greeshma; J.P. Chang; Y.H. Chen; J.P. Cheng; W.H. Dai; Z. Deng; C.H. Fang; X.P. Geng; H. Gong; Q.J. Guo; T. Guo; X.Y. Guo; L. He; S.M. He; J.W. Hu; H.X. Huang; T.C. Huang; L. Jiang; S. Karmakar; H.B. Li; H.Y. Li; J.M. Li; J. Li; Q.Y. Li; R.M.J. Li; X.Q. Li; Y.L. Li; Y.F. Liang; B. Liao; F.K. Lin; S.T. Lin; J.X. Liu; S.K. Liu; Y.D. Liu; Y. Liu; Y.Y. Liu; H. Ma; Y.C. Mao; Q.Y. Nie; J.H. Ning; H. Pan; N.C. Qi; J. Ren; X.C. Ruan; M.K. Singh; T.X. Sun; C.J. Tang; Y. Tian; G.F. Wang; J.Z. Wang; L. Wang; Q. Wang; Y.F. Wang; Y.X. Wang; H.T. Wong; S.Y. Wu; Y.C. Wu; H.Y. Xing; R. Xu; Y. Xu; T. Xue; Y.L. Yan; N. Yi; C.X. Yu; H.J. Yu; J.F. Yue; M. Zeng; Z. Zeng; B.T. Zhang; F.S. Zhang; L. Zhang; Z.H. Zhang; J.Z. Zhao; K.K. Zhao; M.G. Zhao; J.F. Zhou; Z.Y. Zhou; J.J. Zhu
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·day dataset from the CDEX-10 experiment. In the heavy mediator scenario, our result excels in the mass range of 5-15 keV/c2, 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/c2 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. © 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.
First results on low-mass WIMPs from the CDEX-1 experiment at the China Jinping underground laboratory
(2013) W. Zhao; Q. Yue; K.J. Kang; J.P. Cheng; Y.J. Li; S.T. Lin; Y. Bai; Y. Bi; J.P. Chang; N. Chen; N. Chen; Q.H. Chen; Y.H. Chen; Y.C. Chuang; Z. Deng; C. Du; Q. Du; H. Gong; X.Q. Hao; H.J. He; Q.J. He; X.H. Hu; H.X. Huang; T.R. Huang; H. Jiang; H.B. Li; J.M. Li; J. Li; X. Li; X.Y. Li; Y.L. Li; H.Y. Liao; F.K. Lin; S.K. Liu; L.C. Lü; H. Ma; S.J. Mao; J.Q. Qin; J. Ren; J. Ren; X.C. Ruan; M.B. Shen; L. Singh; M.K. Singh; A.K. Soma; J. Su; C.J. Tang; C.H. Tseng; J.M. Wang; L. Wang; Q. Wang; H.T. Wong; S.Y. Wu; W. Wu; Y.C. Wu; Y.C. Wu; Z.Z. Xianyu; H.Y. Xing; Y. Xu; X.J. Xu; T. Xue; L.T. Yang; S.W. Yang; N. Yi; C.X. Yu; H. Yu; X.Z. Yu; X.H. Zeng; Z. Zeng; L. Zhang; Y.H. Zhang; M.G. Zhao; S.N. Zhong; Z.Y. Zhou; J.J. Zhu; W.B. Zhu; X.Z. Zhu; Z.H. Zhu
The China Dark Matter Experiment Collaboration reports the first experimental limit on weakly interacting massive particles (WIMPs) dark matter from 14.6 kg-days of data taken with a 994 g p-type point-contact germanium detector at the China Jinping underground laboratory where the rock overburden is more than 2400 m. The energy threshold achieved was 400 eVee. According to the 14.6 kg-day live data, we placed the limit of σχN=1. 75×10-40 cm2 at a 90% confidence level on the spin-independent cross section at a WIMP mass of 7 GeV before differentiating bulk signals from the surface backgrounds. © 2013 American Physical Society.
Improved limits on solar axions and bosonic dark matter from the CDEX-1B experiment using the profile likelihood ratio method
(American Physical Society, 2020) Y. Wang; Q. Yue; S.K. Liu; K.J. Kang; Y.J. Li; H.P. An; J.P. Chang; J.H. Chen; Y.H. Chen; J.P. Cheng; W.H. Dai; Z. Deng; X.P. Geng; H. Gong; P. Gu; X.Y. Guo; H.T. He; L. He; S.M. He; J.W. Hu; H.X. Huang; T.C. Huang; L.P. Jia; H.B. Li; H. Li; M.X. Li; J.M. Li; J. Li; X. Li; X.Q. Li; Y.L. Li; B. Liao; F.K. Lin; S.T. Lin; Y.D. Liu; Y.Y. Liu; Z.Z. Liu; H. Ma; Q.Y. Nie; J.H. Ning; H. Pan; N.C. Qi; C.K. Qiao; J. Ren; X.C. Ruan; V. Sharma; Z. She; L. Singh; M.K. Singh; T.X. Sun; C.J. Tang; W.Y. Tang; Y. Tian; G.F. Wang; L. Wang; Q. Wang; Z. Wang; H.T. Wong; S.Y. Wu; Y.C. Wu; H.Y. Xing; Y. Xu; T. Xue; Y.L. Yan; L.T. Yang; N. Yi; C.X. Yu; H.J. Yu; J.F. Yue; X.H. Zeng; M. Zeng; Z. Zeng; B.T. Zhang; F.S. Zhang; L. Zhang; Z.Y. Zhang; M.G. Zhao; J.F. Zhou; Z.Y. Zhou; J.J. Zhu
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 significantly improves the sensitivity for the bosonic dark matter below 0.8 keV among germanium detectors. Limits are also placed on the coupling gAe<2.48×10-11 from Compton, bremsstrahlung, atomic-recombination, and deexcitation channels and gANeff×gAe<4.14×10-17 from a Fe57 M1 transition at 90% confidence level. © 2020 authors.
Limits on light weakly interacting massive particles from the CDEX-1 experiment with a p -type point-contact germanium detector at the China Jinping Underground Laboratory
(American Physical Society, 2014) Q. Yue; W. Zhao; K.J. Kang; J.P. Cheng; Y.J. Li; S.T. Lin; J.P. Chang; N. Chen; Q.H. Chen; Y.H. Chen; Y.C. Chuang; Z. Deng; Q. Du; H. Gong; X.Q. Hao; H.J. He; Q.J. He; H.X. Huang; T.R. Huang; H. Jiang; H.B. Li; J.M. Li; J. Li; J. Li; X. Li; X.Y. Li; Y.L. Li; H.Y. Liao; F.K. Lin; S.K. Liu; L.C. Lü; H. Ma; S.J. Mao; J.Q. Qin; J. Ren; J. Ren; X.C. Ruan; M.B. Shen; L. Singh; M.K. Singh; A.K. Soma; J. Su; C.J. Tang; C.H. Tseng; J.M. Wang; L. Wang; Q. Wang; H.T. Wong; S.Y. Wu; Y.C. Wu; Y.C. Wu; Z.Z. Xianyu; R.Q. Xiao; H.Y. Xing; F.Z. Xu; Y. Xu; X.J. Xu; T. Xue; L.T. Yang; S.W. Yang; N. Yi; C.X. Yu; H. Yu; X.Z. Yu; X.H. Zeng; Z. Zeng; L. Zhang; Y.H. Zhang; M.G. Zhao; Z.Y. Zhou; J.J. Zhu; W.B. Zhu; X.Z. Zhu; Z.H. Zhu
We report results of a search for light dark matter weakly interacting massive particles (WIMPs) with CDEX-1 experiment at the China Jinping Underground Laboratory, based on 53.9 kg-days of data from a p-type point-contact germanium detector enclosed by a NaI(Tl) crystal scintillator as anti-Compton detector. The event rate and spectrum above the analysis threshold of 475 eVee are consistent with the understood background model. Part of the allowed regions for WIMP-nucleus coherent elastic scattering at WIMP mass of 6-20 GeV are probed and excluded. Independent of interaction channels, this result contradicts the interpretation that the anomalous excesses of the CoGeNT experiment are induced by dark matter, since identical detector techniques are used in both experiments. © 2014 American Physical Society.
Limits on Light Weakly Interacting Massive Particles from the First 102.8 kg×day Data of the CDEX-10 Experiment
(American Physical Society, 2018) 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 8×10-42 and 3×10-36 cm2 at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (mχ) of 5 GeV/c2 are achieved. The lower reach of mχ is extended to 2 GeV/c2. © 2018 authors. Published by the American Physical Society.
Limits on light WIMPs with a germanium detector at 177 eVee threshold at the China Jinping Underground Laboratory
(2014) S.K. Liu; Q. Yue; K.J. Kang; J.P. Cheng; H.T. Wong; Y.J. Li; S.T. Lin; J.P. Chang; N. Chen; Q.H. Chen; Y.H. Chen; Y.C. Chuang; Z. Deng; Q. Du; H. Gong; X.Q. Hao; H.J. He; Q.J. He; H.X. Huang; T.R. Huang; H. Jiang; H.B. Li; J.M. Li; J. Li; X. Li; X.Q. Li; X.Y. Li; Y.L. Li; H.Y. Liao; F.K. Lin; L.C. Lü; H. Ma; S.J. Mao; J.Q. Qin; J. Ren; J. Ren; X.C. Ruan; M.B. Shen; L. Singh; M.K. Singh; A.K. Soma; J. Su; C.J. Tang; C.H. Tseng; J.M. Wang; L. Wang; Q. Wang; S.Y. Wu; Y.C. Wu; Y.C. Wu; Z.Z. Xianyu; R.Q. Xiao; H.Y. Xing; F.Z. Xu; Y. Xu; X.J. Xu; T. Xue; C.W. Yang; L.T. Yang; S.W. Yang; N. Yi; C.X. Yu; H. Yu; X.Z. Yu; X.H. Zeng; Z. Zeng; L. Zhang; Y.H. Zhang; M.G. Zhao; W. Zhao; Z.Y. Zhou; J.J. Zhu; W.B. Zhu; X.Z. Zhu; Z.H. Zhu
The China Dark Matter Experiment reports results on light WIMP dark matter searches at the China Jinping Underground Laboratory with a germanium detector array with a total mass of 20 g. The physics threshold achieved is 177 eVee ("ee" represents electron equivalent energy) at 50% signal efficiency. With 0.784 kg-days of data, exclusion region on spin-independent coupling with the nucleon is derived, improving over our earlier bounds at WIMP mass less than 4.6 GeV. © 2014 American Physical Society.
Limits on spin-independent couplings of wimp dark matter with a p-type point-contact germanium detector
(2013) H.B. Li; H.Y. Liao; S.T. Lin; S.K. Liu; L. Singh; M.K. Singh; A.K. Soma; H.T. Wong; Y.C. Wu; W. Zhao; G. Asryan; Y.C. Chuang; M. Deniz; J.M. Fang; C.L. Hsu; T.R. Huang; G. Kiran Kumar; S.C. Lee; J. Li; J.M. Li; Y.J. Li; Y.L. Li; C.W. Lin; F.K. Lin; Y.F. Liu; H. Ma; X.C. Ruan; Y.T. Shen; V. Singh; C.J. Tang; C.H. Tseng; Y. Xu; S.W. Yang; C.X. Yu; Q. Yue; Z. Zeng; M. Zeyrek; Z.Y. Zhou
We report new limits on a spin-independent weakly interacting massive particle (WIMP)-nucleon interaction cross section using 39.5 kg days of data taken with a p-type point-contact germanium detector of 840 g fiducial mass at the Kuo-Sheng Reactor Neutrino Laboratory. Crucial to this study is the understanding of the selection procedures and, in particular, the bulk-surface events differentiation at the sub-keV range. The signal-retaining and background-rejecting efficiencies were measured with calibration gamma sources and a novel n-type point-contact germanium detector. Part of the parameter space in the cross section versus WIMP-mass implied by various experiments is probed and excluded. © 2013 American Physical Society.
Measurement of the intrinsic radiopurity of 137Cs/ 235U/238U/232Th in CsI(Tl) crystal scintillators
(2006) Y.F. Zhu; S.T. Lin; V. Singh; W.C. Chang; M. Deniz; W.P. Lai; H.B. Li; J. Li; Y.L. Li; H.Y. Liao; F.S. Lee; H.T. Wong; S.C. Wu; Q. Yue; Z.Y. Zhou
The inorganic crystal scintillator CsI(Tl) has been used for low energy neutrino and Dark Matter experiments, where the intrinsic radiopurity is an issue of major importance. Low-background data were taken with a CsI(Tl) crystal array at the Kuo-Sheng Reactor Neutrino Laboratory. The pulse shape discrimination capabilities of the crystal, as well as the temporal and spatial correlations of the events, provide powerful means of measuring the intrinsic radiopurity of 137Cs as well as the 235U, 238U and 232Th series. The event selection algorithms are described, with which the decay half-lives of 218Po, 214Po, 220Rn, 216Po and 212Po were derived. The measurements of the contamination levels, their concentration gradients with the crystal growth axis, and the uniformity among different crystal samples, are reported. The radiopurity in the 238U and 232Th series are comparable to those of the best reported in other crystal scintillators. Significant improvements in measurement sensitivities were achieved, similar to those from dedicated massive liquid scintillator detector. This analysis also provides in situ measurements of the detector performance parameters, such as spatial resolution, quenching factors, and data acquisition dead time. © 2005 Elsevier B.V. All rights reserved.