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1. An Enigmatic PeVatron in an Area around H ii Region G35.6−0.5

Author

Zhen Cao, F. Aharonian, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, W. Bian, A. V. Bukevich, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, B. Q. Chen, E. S. Chen, H. X. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. C. Chu, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, J. H. Fang, K. Fang, C. F. Feng, H. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, T. T. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, J. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, O. A. Hannuksela, M. Hasan, H. H. He, H. N. He, J. Y. He, Y. He, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, C. Huang, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, Y. Y. Huang, X. L. Ji, H. Y. Jia, K. Jia, H. B. Jiang, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, I. Karpikov, D. Khangulyan, D. Kuleshov, K. Kurinov, B. B. Li, C. M. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, Jian Li, Jie Li, K. Li, S. D. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, D. B. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, M. Y. Liu, R. Y. Liu, S.M. Liu, W. Liu, Y. Liu, Y. N. Liu, Q. Luo, Y. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, K. C. Y. Ng, L. J. Ou, P. Pattarakijwanich, Z. Y. Pei, J. C. Qi, M. Y. Qi, B. Q. Qiao, J. J. Qin, A. Raza, D. Ruffolo, A. Sáiz, M. Saeed, D. Semikoz, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, D. X. Sun, Q. N. Sun, X. N. Sun, Z. B. Sun, J. Takata, P. H. T. Tam, Q. W. Tang, R. Tang, Z. B. Tang, W. W. Tian, L. H. Wan, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, Kai Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, Q. W. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, Y. L. Xin, Y. Xing, D. R. Xiong, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, C. Y. Yang, F. Yang, F. F. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, W. X. Yang, Y. H. Yao, Z. G. Yao, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, X. H. Zhao, F. Zheng, W. J. Zhong, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, B. Y. Zhu, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, Y. C. Zou, X. Zuo, and (The LHAASO Collaboration)

Subjects
Gamma-rays, Gamma-ray sources, H II regions, Supernova remnants, Astrophysics, QB460-466
Abstract

Identifying Galactic PeVatrons (PeV particle accelerators) from ultrahigh-energy (UHE, >100 TeV) γ -ray sources plays a crucial role in revealing the origin of Galactic cosmic rays. The UHE source 1LHAASO J1857+0203u is suggested to be associated with HESS J1858+020, which may be attributed to the possible PeVatron candidate supernova remnant (SNR) G35.6−0.4 or H ii region G35.6−0.5. We perform detailed analysis on the very-high-energy and UHE γ -ray emissions toward this region with data from the Large High Altitude Air Shower Observatory (LHAASO). 1LHAASO J1857+0203u is detected with a significance of 11.6 σ above 100 TeV, indicating the presence of a PeVatron. It has an extent of ∼0 $\mathop{.}\limits^{\unicode{x000B0}}$ 18 with a power-law (PL) spectral index of ∼2.5 at 1–25 TeV and pointlike emission with a PL spectral index of ∼3.2 above 25 TeV. Using archival CO and H i data, we identify some molecular and atomic clouds that may be associated with the TeV γ -ray emissions. Our modeling indicates that the TeV γ -ray emissions are unlikely to arise from clouds illuminated by the protons that escaped from SNR G35.6−0.4. In the scenario in which H ii region G35.6−0.5 could accelerate particles to the UHE band, the observed GeV–TeV γ -ray emission could be well explained by a hadronic model with a PL spectral index of ∼2.0 and cutoff energy of ∼450 TeV. However, an origin in an evolved pulsar wind nebula cannot be ruled out.

Published
2025
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2. Discovery of Very High Energy Gamma-Ray Emissions from the Low-luminosity AGN NGC 4278 by LHAASO

Author

Zhen Cao, F. Aharonian, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, W. Bian, A. V. Bukevich, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, E. S. Chen, H. X. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, J. H. Fang, K. Fang, C. F. Feng, H. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, M. Hasan, H. H. He, H. N. He, J. Y. He, Y. He, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, X. L. Ji, H. Y. Jia, K. Jia, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, I. Karpikov, D. Kuleshov, K. Kurinov, B. B. Li, C. M. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, Jian Li, Jie Li, K. Li, S. D. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, D. B. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, Q. Luo, Y. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, L. J. Ou, P. Pattarakijwanich, Z. Y. Pei, J. C. Qi, M. Y. Qi, B. Q. Qiao, J. J. Qin, A. Raza, D. Ruffolo, A. Sáiz, M. Saeed, D. Semikoz, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, D. X. Sun, Q. N. Sun, X. N. Sun, Z. B. Sun, J. Takata, P. H. T. Tam, Q. W. Tang, R. Tang, Z. B. Tang, W. W. Tian, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, Kai Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, Q. W. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, Y. L. Xin, Y. Xing, D. R. Xiong, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, C. Y. Yang, F. Yang, F. F. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, W. X. Yang, Y. H. Yao, Z. G. Yao, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, X. H. Zhao, F. Zheng, W. J. Zhong, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, B. Y. Zhu, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, Y. C. Zou, X. Zuo, and The LHAASO Collaboration

Subjects
High energy astrophysics, Gamma-ray astronomy, Low-luminosity active galactic nuclei, LINER galaxies, Blazars, Fanaroff-Riley radio galaxies, Astrophysics, QB460-466
Abstract

The first source catalog of the Large High Altitude Air Shower Observatory (LHAASO) reported the detection of a very high energy gamma-ray source, 1LHAASO J1219+2915. This Letter presents a further detailed study of the spectral and temporal behavior of this pointlike source. The best-fit position of the TeV source (R.A. = 185.°05 ± 0.°04, decl. = 29.°25 ± 0.°03) is compatible with NGC 4278 within ∼0.°03. Variation analysis shows an indication of variability on a timescale of a few months in the TeV band, which is consistent with low-frequency observations. Based on these observations, we report the detection of TeV γ -ray emissions from this low-luminosity active galactic nucleus. The observation by LHAASO's Water Cherenkov Detector Array during the active period has a significance level of 8.8 σ with a best-fit photon spectral index Γ = 2.56 ± 0.14 and a flux f _1–10 TeV = (7.0 ± 1.1 _sta ± 0.35 _syst ) × 10 ^−13 photons cm ^−2 s ^−1 , or approximately 5% of the Crab Nebula. The discovery of VHE gamma-ray emission from NGC 4278 indicates that compact, weak radio jets can efficiently accelerate particles and emit TeV photons.

Published
2024
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3. Detection of Very High-energy Gamma-Ray Emission from the Radio Galaxy M87 with LHAASO

Author

Zhen Cao, F. Aharonian, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, W. Bian, A. V. Bukevich, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, E. S. Chen, H. X. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. C. Chu, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, J. H. Fang, K. Fang, C. F. Feng, H. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, T. T. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, J. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, O. A. Hannuksela, M. Hasan, H. H. He, H. N. He, J. Y. He, Y. He, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, C. Huang, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, Y. Y. Huang, X. L. Ji, H. Y. Jia, K. Jia, H. B. Jiang, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, I. Karpikov, D. Khangulyan, D. Kuleshov, K. Kurinov, B. B. Li, C. M. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, Jian Li, Jie Li, K. Li, S. D. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, D. B. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, Q. Luo, Y. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, K. C. Y. Ng, L. J. Ou, P. Pattarakijwanich, Z. Y. Pei, J. C. Qi, M. Y. Qi, B. Q. Qiao, J. J. Qin, A. Raza, D. Ruffolo, A. Sáiz, M. Saeed, D. Semikoz, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, D. X. Sun, Q. N. Sun, X. N. Sun, Z. B. Sun, J. Takata, P. H. T. Tam, Q. W. Tang, R. Tang, Z. B. Tang, W. W. Tian, L. H. Wan, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, Kai Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, Q. W. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, Y. L. Xin, Y. Xing, D. R. Xiong, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, C. Y. Yang, F. Yang, F. F. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, W. X. Yang, Y. H. Yao, Z. G. Yao, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, X. H. Zhao, F. Zheng, W. J. Zhong, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, B. Y. Zhu, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, Y. C. Zou, and X. Zuo

Subjects
Active galactic nuclei, High energy astrophysics, Astrophysics, QB460-466
Abstract

The nearby radio galaxy M87 is a very high-energy (VHE) gamma-ray emitter established by observations with ground-based gamma-ray detectors. Here we report the long-term monitoring of M87 from 2021 to 2024 with the Large High Altitude Air Shower Observatory (LHAASO). M87 has been detected by LHAASO with a statistical significance ∼ 9 σ . The observed energy spectrum extends to 20 TeV, with a possible hardening at ∼20 TeV and then a clear softening at higher energies. Assuming that the intrinsic spectrum is described by a single power law up to 20 TeV, a tight upper bound on the extragalactic background light intensity is obtained. A strong VHE flare lasting 8 days, with a rise time of ${\tau }_{r}^{\mathrm{rise}}=1.05\pm 0.49$ days and decay time of ${\tau }_{d}^{\mathrm{decay}}=2.17\pm 0.58$ days, was found in early 2022. A possible GeV flare is seen also in Fermi Large Area Telescope data during the VHE flare period. The variability time as short as 1 day seen in the LHAASO data suggests a compact emission region with a size of ∼3 × 10 ^15 δ cm ( δ being the Doppler factor of the emitting region), corresponding to a few Schwarzschild radii of the central supermassive black hole in M87. The continuous monitoring of the source reveals a duty cycle of ∼1% for VHE flares with a flux above 10 ^−11 erg cm ^−2 s ^−1 .

Published
2024
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4. Intelligent optimization of a hybrid renewable energy system using an improved fower pollination algorithm

Author

Y. H. Yu, Y. H. Yu, P. Ong, P. Ong, H. A. Wahab, H. A. Wahab, Y. H. Yu, Y. H. Yu, P. Ong, P. Ong, and H. A. Wahab, H. A. Wahab

Abstract

Renewable energy is an emerging trend to replace fossil fuels as a primary energy source. However, the intermittency of sources and high investment costs inhibit the full-scale adoption of renewable energy as the principal energy producer. This study presented a stand-alone hybrid renewable energy system, comprising solar panels and wind turbines as the primary energy source, with batteries and a diesel engine integrated as a backup system. Attempting to minimize the annualized total cost of investment and carbon emission, this study applied a new optimization algorithm, specifcally the improved fower pollination algorithm, to acquire a techno-economically feasible design of a stand-alone hybrid renewable energy system. Performance comparison with the fower pollination algorithm showed that the proposed improved fower pollination algorithm could converge faster to the optimal solution in single-objective optimization problems. While minimizing both annualized total cost and carbon emission, the confgurations of improved fower pollination algorithm were more dominant and evenly distributed than fower pollination algorithm. Lastly, the sensitivity analysis indicated that the annualized total cost of the hybrid renewable energy system was highly dependent on solar radiation, but not on wind speed.

Published
2024

5. The First LHAASO Catalog of Gamma-Ray Sources

Author

Zhen Cao, F. Aharonian, Q. An, Axikegu, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, J. T. Cai, Q. Cao, W. Y. Cao, Zhe Cao, J. Chang, J. F. Chang, A. M. Chen, E. S. Chen, Liang Chen, Lin Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, M. Y. Cui, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, D. della Volpe, X. Q. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, X. T. Feng, Y. L. Feng, S. Gabici, B. Gao, C. D. Gao, L. Q. Gao, Q. Gao, W. Gao, W. K. Gao, M. M. Ge, L. S. Geng, G. Giacinti, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. Y. He, X. B. He, Y. He, M. Heller, Y. K. Hor, B. W. Hou, C. Hou, X. Hou, H. B. Hu, Q. Hu, S. C. Hu, D. H. Huang, T. Q. Huang, W. J. Huang, X. T. Huang, X. Y. Huang, Y. Huang, Z. C. Huang, X. L. Ji, H. Y. Jia, K. Jia, K. Jiang, X. W. Jiang, Z. J. Jiang, M. Jin, M. M. Kang, T. Ke, D. Kuleshov, K. Kurinov, B. B. Li, Cheng Li, Cong Li, D. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, Jian Li, Jie Li, K. Li, W. L. Li, X. R. Li, Xin Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, R. Lu, Q. Luo, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, Z. Min, W. Mitthumsiri, H. J. Mu, Y. C. Nan, A. Neronov, Z. W. Ou, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, Y. Q. Qi, B. Q. Qiao, J. J. Qin, D. Ruffolo, A. Sáiz, D. Semikoz, C. Y. Shao, L. Shao, O. Shchegolev, X. D. Sheng, F. W. Shu, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Q. W. Tang, Z. B. Tang, W. W. Tian, C. Wang, C. B. Wang, G. W. Wang, H. G. Wang, H. H. Wang, J. C. Wang, K. Wang, L. P. Wang, L. Y. Wang, P. H. Wang, R. Wang, W. Wang, X. G. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, X. F. Wu, Y. S. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, Z. Xiong, D. L. Xu, R. F. Xu, R. X. Xu, W. L. Xu, L. Xue, D. H. Yan, J. Z. Yan, T. Yan, C. W. Yang, F. Yang, F. F. Yang, H. W. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. Yue, H. D. Zeng, T. X. Zeng, W. Zeng, M. Zha, B. B. Zhang, F. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, L. X. Zhang, Li Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. B. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, B. Zhou, H. Zhou, J. N. Zhou, M. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, X. Zuo, and (The LHAASO Collaboration)

Subjects
Gamma-ray astronomy, Gamma-ray observatories, Catalogs, Astrophysics, QB460-466
Abstract

We present the first catalog of very-high-energy and ultra-high-energy gamma-ray sources detected by the Large High Altitude Air Shower Observatory. The catalog was compiled using 508 days of data collected by the Water Cherenkov Detector Array from 2021 March to 2022 September and 933 days of data recorded by the Kilometer Squared Array from 2020 January to 2022 September. This catalog represents the main result from the most sensitive large coverage gamma-ray survey of the sky above 1 TeV, covering decl. from −20° to 80°. In total, the catalog contains 90 sources with an extended size smaller than 2° and a significance of detection at >5 σ . Based on our source association criteria, 32 new TeV sources are proposed in this study. Among the 90 sources, 43 sources are detected with ultra-high energy ( E > 100 TeV) emission at >4 σ significance level. We provide the position, extension, and spectral characteristics of all the sources in this catalog.

Published
2024
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6. Construction and on-site performance of the LHAASO WFCTA camera

Author

F. Aharonian, Q. An, Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, J. Chang, J. F. Chang, X. C. Chang, B. M. Chen, J. Chen, L. Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, Danzengluobu, D. della Volpe, B. D’Ettorre Piazzoli, X. J. Dong, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, X. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, D. Kuleshov, K. Levochkin, B. B. Li, C. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. Li, X. R. Li, Y. Li, Y. Z. Li, Z. Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. R. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. Wang, Z. H. Wang, Z. X. Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. Zhang, L. X. Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S S. Zhang, X. Zhang, X. P. Zhang, Y. Zhang, Y. F. Zhang, Y. L. Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, X. Zuo, and The LHAASO Collaboration

Subjects
Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract The focal plane camera is the core component of the Wide Field-of-view Cherenkov/fluorescence Telescope Array (WFCTA) of the Large High-Altitude Air Shower Observatory (LHAASO). Because of the capability of working under moonlight without aging, silicon photomultipliers (SiPM) have been proven to be not only an alternative but also an improvement to conventional photomultiplier tubes (PMT) in this application. Eighteen SiPM-based cameras with square light funnels have been built for WFCTA. The telescopes have collected more than 100 million cosmic ray events and preliminary results indicate that these cameras are capable of working under moonlight. The characteristics of the light funnels and SiPMs pose challenges (e.g. dynamic range, dark count rate, assembly techniques). In this paper, we present the design features, manufacturing techniques and performances of these cameras. Finally, the test facilities, the test methods and results of SiPMs in the cameras are reported here.

Published
2021
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7. The effect of polymorphism in the FADS2 gene on the fatty acid composition of bovine milk

Author

W. S. Proskura, M. Liput, D. Zaborski, Z. Sobek, Y.-H. Yu, Y.-H. Cheng, and A. Dybus

Subjects
Agriculture, Animal culture, SF1-1100, Science, Zoology, QL1-991
Abstract

Polyunsaturated fatty acids (PUFAs) play a role in a wide variety of physiological processes. They are produced by a series of desaturation and elongation reactions. Δ-6-desaturase is a membrane-bound enzyme that catalyzes the conversion of α-linolenic acid (C18:3n-3) and linoleic acid (C18:2n-6) to stearidonic acid (18:4n-3) and γ-linolenic acid (18:3n-6). It is encoded by the FADS2 gene located on bovine chromosome 29. The aim of this study was to identify a single nucleotide polymorphism in the FADS2 gene and to determine possible associations with milk fatty acid composition in two breeds of dairy cattle, i.e., Jersey and Polish Holstein-Friesian. Direct DNA sequencing revealed the presence of an A-to-G substitution in intron 3 of the FADS2 gene (rs209202414). Both populations were genotyped with an appropriate PCR-RFLP assay. The following genotype distributions were observed: for Jerseys, AA = 0.24, AG = 0.63, and GG = 0.13; for Polish Holstein-Friesians, AA = 0.17, AG = 0.40, and GG = 0.43. In Jerseys, statistically significant relationships were found between the FASD2 genotypes and the following milk fatty acids: lauric (P=0.0486), behenic (P=0.0199), lignoceric (P=0.0209), oleic (P=0.0386), eicosatrienoic (P=0.0113), and docosadienoic (P=0.0181). In Polish Holstein-Friesian cows, significant associations were observed for erucic (P=0.0460) and docosahexaenoic (P=0.0469) acids. The study indicated the A-to-G substitution (rs209202414) in the bovine FADS2 gene as a potential genetic marker for fatty acid composition in cattle milk.

Published
2019
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8. Composite coating with synergistic effect of biomimetic epoxy thermoset morphology and incorporated superhydrophobic silica for corrosion protection

Author

W. F. Ji, C. W. Li, W. J. Huang, H. K. Yu, R. D. Chen, Y. H. Yu, J. M. Yeh, W. C. Tang, and Y. C. Su

Subjects
Polymer composites, Methyl-modified silica microsp, Epoxy resin, Biomimetic, Corrosion protection, Materials of engineering and construction. Mechanics of materials, TA401-492, Chemical technology, TP1-1185
Abstract

In this work, potential anticorrosive coating resulted from the composite with synergistic effect of biomimetic epoxy thermoset (BET) morphology and incorporated superhydrophobic silica microspheres was presented. First of all, superhydrophobic methyl-modified silica (MS) microspheres were synthesized by performing the conventional base-catalyzed sol-gel process of MTMS and APTMS. The as-prepared MS microspheres were identified as having an average particle size of ~1 µm in diameter. The as-prepared MS microspheres were characterized by Fourier transform infrared spectrometry (FTIR), 29Si and 13C solid-state nuclear magnetic resonance (NMR) spectroscopy. Morphological properties of MS microspheres and BET-silica composite coating were studied by scanning electron microscopy (SEM). Subsequently, 3 wt% of MS microspheres were incorporated into an epoxy slurry of DGEBA/T-403 in dimetyl acetamide (DMAc), followed by performing the programmed heating through nanocasting technique with PDMS as soft template materials for pattern transfer by using leaf of Xanthosoma Sagittifolium as natural template, leading to the formation of artificial biomimetic composite coating. The appearance/dispersion capability of silica microspheres in BET coating was confirmed by the energy dispersive X-ray spectroscopy (EDX) and Si-mapping. The roughness level of BET and BEC-3% were detected by AFM. The BETsilica composite was found to exhibit a contact angle (CA) of ~153°, revealing the synergistic effect of biomimetic epoxy morphology and incorporated superhydrophobic MS microspheres, which is found to be more hydrophobic than that of neat epoxy thermoset (CA = 81°). Corrosion protection of as-prepared coatings was demonstrated by performing a series of electrochemical measurements (Tafel, Nyquists and Bode plots) upon CRS electrodes in saline condition. It should be noted that the BET coatings upon CRS electrode revealed an effectively enhanced corrosion protection as compared to that coatings without biomimetic morphology. Moreover, the BET coating with superhydrophobic MS microspheres upon CRS electrode was found to exhibit better corrosion protection as compared to a counterpart coating without MS microspheres.

Published
2016
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9. VvZFP11, a Cys2His2-type zinc finger transcription factor, is involved in defense responses in Vitis vinifera

Author

Y.-H. Yu, X.-Z. Li, Z.-J. Wu, D.-X. Chen, G.-R. Li, X.-Q. Li, and G.-H. Zhang

Subjects
erisiphe necator, golovinomyces cichoracearum, grapevine, methyl jasmonate, salicylic acid, zinc finger protein, Biology (General), QH301-705.5, Plant ecology, QK900-989
Abstract

In plants, many C2H2-type zinc finger transcription factors function in plant defense responses to biotic and abiotic stresses. Here, we report cloning and characterization of VvZFP11 which encoded a C2H2-type zinc finger protein (ZFP) in grapevine (Vitis vinifera). Sequence analysis shows that VvZFP11 contained one L-box, two C2H2-type zinc finger motifs and one ERF-associated amphiphilic repression (EAR) motif. The VvZFP11 localized to the nucleus and functional analysis shows that full-length VvZFP11 had no transcriptional activity, but VvZFP11 lacking the EAR motif had a strong transcriptional activity in yeast. In grapevine, expression of VvZFP11 was induced by salicylic acid and methyl jasmonate and also quickly responded to infection with Erisiphe necator. Arabidopsis thaliana plants overexpressing VvZFP11 were more resistant to Golovinomyces cichoracearum, and real time quantitative polymerase chain reaction revealed that defense-related genes AtPR1 and AtPDF1.2 were up-regulated in the overexpressing lines. These results suggest that VvZFP11 might play an important role in defense responses in grapevine.

Published
2016
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10. Influence of Nutritional Status on a Family-Centered Care Intervention for Older Adults with Cognitive Impairment following Hip-Fracture Surgery: Secondary Data Analysis of a Randomized Controlled Trial

Author

M.-Y. Tseng, J. Liang, C.-C. Wu, H.-S. Cheng, C.-Y. Chen, Y.-E. Lin, C.-J. Weng, Y.-H. Yu, and Yea-Ing L. Shyu

Subjects
Nutrition and Dietetics, Hip Fractures, Medicine (miscellaneous), Nutritional Status, Aftercare, Patient Discharge, Secondary Data Analysis, Patient-Centered Care, Activities of Daily Living, Quality of Life, Humans, Cognitive Dysfunction, Geriatrics and Gerontology, Aged
Abstract

In Taiwan, older adults with cognitive impairment who undergo hip-fracture surgery are routinely cared for by family members. This study aimed to determine if nutritional status influenced the effects of a family-centered intervention for older adults with cognitive impairment recovering from hip-fracture surgery.Secondary data analysis of data from a randomized controlled trial was conducted to examine the influences of nutritional status 1 month after hospital discharge on the effects of a family-centered care intervention model, which was designed for older adults with hip fracture and cognitive impairment. Outcomes were compared among participants according to nutrition status (well-nourished/poorly-nourished) and treatment approach (control/intervention).The original study was conducted at a 3000-bed medical center from July 2015 to October 2019.Participants were older adults with cognitive impairment who had undergone hip-fracture surgery. Participants were assessed as poorly-nourished or well-nourished with the Mini-Nutritional Assessment (MNA) 1-month post-discharge and were then randomly assigned to either the intervention group or control group.A family-centered intervention model for family caregivers of older adults with cognitive impairment recovering from hip-fracture surgery was implemented. The intervention was delivered by geriatric nurses, which included instructions for family caregivers in overseeing exercises for strengthening the hip, understanding dietary requirements, and managing behavioral problems associated with cognitive impairment.Outcome measures included activities of daily living (ADLs), instrumental ADLs, hip range of motion, hip muscle strength, depression, measured with the Geriatric Depressive Scale, and physical and mental health related quality of life, measured with the Short Form Survey (SF-36), Taiwanese version. Participants were assessed at 1-, 3-, 6-, and 12-months post-discharge.Most of the 134 participants were assessed as poorly nourished (n = 122); 57 were the control group and 65 received the intervention. For the well-nourished participants (n = 12), four were in the intervention group and eight were controls. There were no significant differences in any outcome variables for poorly nourished participants who received the intervention compared with controls. For the sample of well-nourished participants, those who received the intervention performed significantly better in outcomes of IADLs (b = 1.74, p.05), hip muscle strength (b = 9.64, p.01), and physical health related quality of life (b = 10.47, p.01).The family-centered care intervention was only effective for older adults with cognitive impairment recovering from hip-fracture surgery who were well-nourished at 1 month following hospital discharge, but not for those at risk of malnutrition. Interventions should focus on enhancing nutritional status following hip surgery which could allow the family-centered in-home intervention to be beneficial for more older adults with cognitive impairment recovering from hip-fracture surgery.

Published
2022

11. Line-of-shower trigger method to lower energy threshold for GRB detection using LHAASO-WCDA

Author

C. F. Feng, Bin Zhou, X. L. Ji, R. Lu, H. B. Xiao, J. R. Shi, W. Zeng, Z. H. Wang, Shengxue Zhang, Pak-Hin Thomas Tam, H. C. Li, Jun Liu, H. Y. Jia, B. D'Ettorre Piazzoli, W. X. Wu, Junjie Mao, Y. Q. Guo, Dong Liu, F. Ji, H. R. Wu, Y. J. Wei, Alejandro Sáiz, Oleg Shchegolev, L. Feng, V. Rulev, L. Xue, Xuliang Chen, Xing-Yuan Hou, D. M. Wei, S. Hu, M. L. Chen, Jianeng Zhou, J. Y. Liu, Warit Mitthumsiri, Y. Zhang, Q. An, Y. He, Q. Gao, Ruizhi Yang, X. N. Sun, H. B. Hu, H. Liu, L. Chen, X. G. Wang, S. Q. Xi, J. Fang, X. H. You, Ping Zhou, Z. C. Huang, Y. Z. Li, P. F. Zhang, C. Y. Wu, Hong-Guang Wang, G. M. Xiang, W. Liu, Yu-Lei Chen, Zihuang Cao, X. C. Chang, Z. K. Zeng, Y. J. Bi, H. D. Liu, Y. D. Cheng, Bo Zhang, Y. Zheng, L. Q. Yin, Duo Yan, F. Zheng, Hao Zhou, X. X. Zhou, Q. Yuan, Hefan Li, J. F. Chang, Z. X. Liu, Felix Aharonian, H. N. He, C. D. Gao, Lei Zhao, Q. H. Chen, Youping Li, Y. M. Ye, B. B. Li, Yongchun Wang, Y. D. Cui, Bai Yibing, L. P. Wang, J. B. Zhao, Y. J. Wang, J. Y. Yang, S. Z. Chen, Yunchao Liu, B. Z. Dai, Rong Xu, Z. X. Fan, Z. Y. You, Z. G. Dai, X. F. Wu, He Zhang, S. H. Feng, S. B. Yang, J. J. Xia, W. Gao, S. L. He, Y. P. Wang, B. M. Chen, Fan Yang, A. Masood, Kun Fang, S.H. Chen, Yugang Zhang, H. Cai, Lang Shao, H. Wang, J.W. Xia, L. Z. Zhao, G. C. Xiao, X. X. Zhai, Y. C. Nan, Shi-Qi Hu, X. J. Bi, Z. Li, R. Liu, E. W. Liang, X. Zuo, M. J. Yang, Y. H. Yao, W. L. Li, L. X. Zhang, H. K. Lv, Xufang Li, B. Y. Pang, Zebo Tang, M. H. Gu, Z. Y. Pei, Xuejiao Li, F. R. Zhu, T. L. Chen, Qie Sun, K. J. Zhu, Ying Zhang, H. M. Zhang, J. Chen, H. L. Dai, Y. L. Xin, T. Wen, S. W. Cui, M. Zha, J. C. He, W. H. Huang, L. X. Bai, Binyu Zhao, Yun-Feng Liang, Jixia Li, X. H. Cui, Xinbo He, K. Jiang, X. J. Hu, J. W. Zhang, Li-Sheng Geng, Wenwu Tian, Z. X. Wang, Xiaofei Zhang, David Ruffolo, Yu. V. Stenkin, C. Hou, Z. B. Sun, Shuibin Lin, Lu Zhang, K. Levochkin, Cheng Guang Zhu, X. D. Sheng, Minghao Qi, Houdun Zeng, Jun-Jie Wei, Jia Zhang, Y. A. Han, H. B. Li, Danzengluobu, Rui Zhang, H. C. Song, Linbin Yang, Y. Z. Fan, J. T. Cai, H. H. He, Y. M. Xing, F. Y. Li, D. H. Huang, H. Zhu, Xiang Zhang, M. M. Ge, J. G. Guo, S. R. Zhang, N. Cheng, L. L. Ma, G. H. Gong, J. S. Wang, Cunguo Wang, Shujuan Liu, N. Yin, Y. H. Yu, W. J. Long, Axikegu, Xuelong Wang, P. P. Zhang, Chunlong Li, Minghui Liu, D. Bastieri, Jinyao Liu, Z. G. Yao, X. H. Ma, M. Heller, K. Li, Z. J. Jiang, J. Liu, R. N. Wang, V. I. Stepanov, Jian Wang, Chiming Jin, D.A. Kuleshov, G. G. Xin, M. J. Chen, S. P. Zhao, Y. Y. Guo, Donglian Xu, X. L. Guo, X. J. Dong, Y. K. Hor, T. Montaruli, Y. L. Feng, W. Wang, P. Pattarakijwanich, S. Wu, B. D. Wang, C. X. Liu, Y. W. Bao, X. T. Huang, R. Zhou, L. Y. Wang, D. della Volpe, C. W. Yang, Jun-Hui Fan, Zujian Wang, Q. B. Gou, Qizhi Huang, B. Liu, Bingshui Gao, Xiang-Yu Wang, Tao Zeng, and Bin Ma

Subjects
Physics, Nuclear and High Energy Physics, Cherenkov detector, Astrophysics::High Energy Astrophysical Phenomena, Detector, Astrophysics, law.invention, Air shower, Nuclear Energy and Engineering, Duty cycle, law, Observatory, Gamma-ray burst, Energy (signal processing), Line (formation)
Abstract

Observation of high energy and very high emission from Gamma Ray Bursts (GRBs) is crucial to study the gigantic explosion and the underline processes. With a large field-of-view and almost full duty cycle, the Water Cherenkov Detector Array (WCDA), a sub-array of the Large High Altitude Air Shower Observatory (LHAASO), is appropriate to monitor the very high energy emission from unpredictable transients such as GRBs. Nevertheless, the main issue for an extensive air shower array is the high energy threshold which limits the horizon of the detector. To address this issue a new trigger method is developed in this article to lower the energy threshold of WCDA for GRB observation. The proposed method significantly improves the detection efficiency of WCDA for gamma-rays around the GRB direction at 10-300 GeV. The sensitivity of the WCDA for GRB detection with the new trigger method is estimated. The achieved sensitivity of the quarter WCDA array above 10 GeV is comparable with that of Fermi-LAT. The data analysis process and corresponding fluence upper limit for GRB 190719C is presented as an example.

Published
2021
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12. A dynamic range extension system for LHAASO WCDA-1

Author

F. Aharonian, Q. An, null Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, J. Chang, J. F. Chang, X. C. Chang, B. M. Chen, J. Chen, L. Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, null Danzengluobu, D. della Volpe, B. D’Ettorre Piazzoli, X. J. Dong, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, X. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, Y. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, D. Kuleshov, K. Levochkin, B. B. Li, C. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. Li, X. R. Li, Y. Li, Y. Z. Li, Z. Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. R. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. Wang, Z. H. Wang, Z. X. Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. Zhang, L. X. Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. Zhang, Y. F. Zhang, Y. L. Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, and X. Zuo

Subjects
Physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Dynamic range, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Extension (predicate logic), Measure (mathematics), Effective nuclear charge, Nuclear physics, Air shower, Nuclear Energy and Engineering, Orders of magnitude (time), Energy (signal processing)
Abstract

The main scientific goal of LHAASO-WCDA is to survey gamma-ray sources with energy from 100 GeV to 30 TeV. To observe high-energy shower events, especially to measure the energy spectrum of cosmic rays from 100 TeV to 10 PeV, a dynamic range extension system (WCDA++) is designed to use a 1.5-inch PMT with a dynamic range of four orders of magnitude for each cell in WCDA-1. The dynamic range is extended by using these PMTs to measure the effective charge density in the core region of air shower events, which is an important parameter for identifying the composition of primary particles. The system has been running for more than one year. In this paper, the details of the design and performance of WCDA++ are presented.

Published
2021
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13. Constraints on heavy decaying dark matter from 570 days of LHAASO observations

Author

Zhen, Cao, F, Aharonian, Q, An, Axikegu, L X, Bai, Y X, Bai, Y W, Bao, D, Bastieri, X J, Bi, Y J, Bi, J T, Cai, Zhe, Cao, J, Chang, J F, Chang, E S, Chen, Liang, Chen, Long, Chen, M J, Chen, M L, Chen, Q H, Chen, S H, Chen, S Z, Chen, T L, Chen, Y, Chen, H L, Cheng, N, Cheng, Y D, Cheng, S W, Cui, X H, Cui, Y D, Cui, B, D'Ettorre Piazzoli, B Z, Dai, H L, Dai, Z G, Dai, Danzengluobu, D, Della Volpe, K K, Duan, J H, Fan, Y Z, Fan, Z X, Fan, J, Fang, K, Fang, C F, Feng, L, Feng, S H, Feng, X T, Feng, Y L, Feng, B, Gao, C D, Gao, L Q, Gao, Q, Gao, W, Gao, W K, Gao, M M, Ge, L S, Geng, G H, Gong, Q B, Gou, M H, Gu, F L, Guo, J G, Guo, X L, Guo, Y Q, Guo, Y Y, Guo, Y A, Han, H H, He, H N, He, S L, He, X B, He, Y, He, M, Heller, Y K, Hor, C, Hou, X, Hou, H B, Hu, Q, Hu, S, Hu, S C, Hu, X J, Hu, D H, Huang, W H, Huang, X T, Huang, X Y, Huang, Y, Huang, Z C, Huang, X L, Ji, H Y, Jia, K, Jia, K, Jiang, Z J, Jiang, M, Jin, M M, Kang, T, Ke, D, Kuleshov, K, Levochkin, B B, Li, Cheng, Li, Cong, Li, F, Li, H B, Li, H C, Li, H Y, Li, J, Li, Jian, Li, Jie, Li, K, Li, W L, Li, X R, Li, Xin, Li, Y Z, Li, Zhe, Li, Zhuo, Li, E W, Liang, Y F, Liang, S J, Lin, B, Liu, C, Liu, D, Liu, H, Liu, H D, Liu, J, Liu, J L, Liu, J S, Liu, J Y, Liu, M Y, Liu, R Y, Liu, S M, Liu, W, Liu, Y, Liu, Y N, Liu, W J, Long, R, Lu, Q, Luo, H K, Lv, B Q, Ma, L L, Ma, X H, Ma, J R, Mao, A, Masood, Z, Min, W, Mitthumsiri, Y C, Nan, Z W, Ou, B Y, Pang, P, Pattarakijwanich, Z Y, Pei, M Y, Qi, Y Q, Qi, B Q, Qiao, J J, Qin, D, Ruffolo, A, Sáiz, C Y, Shao, L, Shao, O, Shchegolev, X D, Sheng, J Y, Shi, H C, Song, Yu V, Stenkin, V, Stepanov, Y, Su, Q N, Sun, X N, Sun, Z B, Sun, P H T, Tam, Z B, Tang, W W, Tian, B D, Wang, C, Wang, H, Wang, H G, Wang, J C, Wang, J S, Wang, L P, Wang, L Y, Wang, R, Wang, R N, Wang, W, Wang, X G, Wang, X Y, Wang, Y, Wang, Y D, Wang, Y J, Wang, Y P, Wang, Z H, Wang, Z X, Wang, Zhen, Wang, Zheng, Wang, D M, Wei, J J, Wei, Y J, Wei, T, Wen, C Y, Wu, H R, Wu, S, Wu, X F, Wu, Y S, Wu, S Q, Xi, J, Xia, J J, Xia, G M, Xiang, D X, Xiao, G, Xiao, G G, Xin, Y L, Xin, Y, Xing, Z, Xiong, D L, Xu, R X, Xu, L, Xue, D H, Yan, J Z, Yan, C W, Yang, F F, Yang, H W, Yang, J Y, Yang, L L, Yang, M J, Yang, R Z, Yang, S B, Yang, Y H, Yao, Z G, Yao, Y M, Ye, L Q, Yin, N, Yin, X H, You, Z Y, You, Y H, Yu, Q, Yuan, H, Yue, H D, Zeng, T X, Zeng, W, Zeng, Z K, Zeng, M, Zha, X X, Zhai, B B, Zhang, F, Zhang, H M, Zhang, H Y, Zhang, J L, Zhang, L X, Zhang, Li, Zhang, Lu, Zhang, P F, Zhang, P P, Zhang, R, Zhang, S B, Zhang, S R, Zhang, S S, Zhang, X, Zhang, X P, Zhang, Y F, Zhang, Y L, Zhang, Yi, Zhang, Yong, Zhang, B, Zhao, J, Zhao, L, Zhao, L Z, Zhao, S P, Zhao, F, Zheng, Y, Zheng, B, Zhou, H, Zhou, J N, Zhou, P, Zhou, R, Zhou, X X, Zhou, C G, Zhu, F R, Zhu, H, Zhu, K J, Zhu, X, Zuo, S, Ando, M, Chianese, D F G, Fiorillo, G, Miele, K C Y, Ng, and GRAPPA (ITFA, IoP, FNWI)

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), High Energy Physics - Phenomenology, Cosmology and Nongalactic Astrophysics (astro-ph.CO), High Energy Physics - Phenomenology (hep-ph), General Physics and Astronomy, FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 105 and 109 GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Published
2022

14. Secular trends of incidence and hospitalization cost of hip fracture in Tangshan, China

Author

Y.-h. Yu, J.-y. Liu, Y.-y. Zhang, X.-h. Fan, X.-x. Sun, G.-l. Cao, Z.-b. Guo, Y.-q. Tian, N. Zhang, Faming Tian, and X.-l. Hou

Subjects
Hip fracture, medicine.medical_specialty, Cervical fracture, business.industry, Endocrinology, Diabetes and Metabolism, Incidence (epidemiology), Osteoporosis, medicine.disease, Secular variation, Hospitalization cost, Orthopedic surgery, medicine, business, Urban hospital, Demography
Abstract

We investigated the secular trends of the incidence and hospitalization cost of hip fracture in Tangshan, China. The incidence of hip fracture and the hospitalization cost were both increasing during the observation period. The present study aimed to determine sex-, age-, and fracture type-specific incidence and annual changes in hip fractures in Tangshan, China, between 2007 and 2018. We analyzed annual hip fracture incidence using urban hospital data during 2007–2018 and calculated incidence rate/100,000 person years in each age group and sex. We assessed annual changes in incidence among people aged >60 years using linear-by-linear association tests and evaluated hospitalization costs with the Kruskal–Wallis test. During the study period, we observed an increasing proportion of hip fractures in people >60 years old from 14.2 to 22.79%. Crude hip fracture incidence increased markedly from 140.87 to 306.56/100,000 in women (p 60 years. Type-specific analysis indicated significantly increased trends in incidence of cervical and trochanteric fractures among women and cervical fracture among men (p < 0.01). In people aged 36–60 years, the trend of hip fracture increased significantly in both sexes. The total and cervical-to-trochanteric ratio in men increased, with significant upward trends (p < 0.01). The proportion of cervical fracture was higher than that for trochanteric fracture in women, with stable levels from 2007 to 2018. Hospitalization costs for cervical and trochanteric fractures increased by 51.91% and 53.20%, respectively, during 2011–2018. Tangshan will have an increasing burden on health care resources attributable to a considerable rise in hip fracture incidence and the older population. Further investigation of risk factors and subsequent implementation of effective measures to prevent hip fracture are needed.

Published
2021
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15. Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

Author

Alejandro Sáiz, Y. H. Yao, W. X. Wu, P. P. Zhang, Zhuo Li, R. Liu, Pak-Hin Thomas Tam, H. C. Li, Liang Chen, J. C. Wang, Y. L. Xin, L. Chen, M. J. Chen, Hong-Guang Wang, Y. J. Wei, S. Hu, Junjie Mao, Y. Q. Guo, J. Y. Liu, V. Rulev, P. F. Zhang, L. Xue, H. B. Hu, H. Liu, Rui Zhang, Linbin Yang, C. F. Feng, F. Ji, Xiaofei Zhang, F. Zheng, V. I. Stepanov, Ping Zhou, Q. H. Chen, H. R. Wu, Warit Mitthumsiri, X. C. Chang, Z. K. Zeng, C. D. Gao, Bin Zhou, W. L. Li, S. Z. Chen, M. M. Ge, Lei Zhao, Y. Z. Li, Y. Y. Guo, Y. J. Bi, Zhe Cao, Y. K. Hor, Xuejiao Li, H. D. Liu, S. H. Feng, B. Liu, Y. D. Cheng, Bo Zhang, H. K. Lv, H. M. Zhang, K. Levochkin, Y. J. Wang, L. X. Bai, Jixia Li, T. Montaruli, Duo Yan, Hefan Li, Ying Zhang, Bingshui Gao, Q. An, H. B. Xiao, J. R. Shi, X. D. Sheng, Z. X. Liu, W. H. Huang, M. L. Chen, Jianeng Zhou, Q. Gao, Minghao Qi, W. Zeng, Li-Sheng Geng, J. Chen, B. M. Chen, T. Wen, S. W. Cui, Z. X. Wang, Chiming Jin, S. B. Yang, L. Z. Zhao, C. W. Yang, J. B. Zhao, D.A. Kuleshov, Y. M. Xing, L. P. Wang, E. W. Liang, X. F. Wu, Zhe Li, B. Y. Pang, B. B. Li, X. Zuo, Cong Li, S. Q. Xi, Kun Fang, W. Gao, B. Z. Dai, Z. H. Wang, H. Cai, Jun Liu, Zhen Wang, J. C. He, Houdun Zeng, J. Fang, G. C. Xiao, Y. C. Nan, Z. G. Yao, Z. Y. Pei, Jun-Hui Fan, X. X. Zhou, Q. Yuan, H. B. Li, Shi-Qi Hu, G. G. Xin, J. F. Chang, Xufang Li, Oleg Shchegolev, G. M. Xiang, S. P. Zhao, W. Liu, X. L. Ji, M. J. Yang, H. H. He, R. Lu, Zhengguo Cao, Felix Aharonian, J. W. Zhang, H. C. Song, Yongchun Wang, Yugang Zhang, Wenwu Tian, He Zhang, Bai Yibing, S. L. He, Donglian Xu, Y. L. Feng, Zebo Tang, X. L. Guo, Y. D. Cui, X. J. Dong, Zheng Wang, Jun-Jie Wei, Q. B. Gou, Qizhi Huang, H. N. He, K. J. Zhu, M. Zha, B. D. Wang, Ruizhi Yang, X. N. Sun, Y. P. Wang, Z. C. Huang, H. L. Dai, H. Wang, Xiang Zhang, Xing-Yuan Hou, Yunchao Liu, H. Y. Jia, D. M. Wei, Z. G. Dai, Rong Xu, Fan Yang, A. Masood, F. Y. Li, Xinbo He, Youping Li, X. T. Huang, L. Y. Wang, X. R. Li, J. J. Xia, K. Jiang, Binyu Zhao, X. J. Hu, Yun-Feng Liang, W. Wang, Y. A. Han, J. G. Guo, Yu. V. Stenkin, Lang Shao, J.W. Xia, P. Pattarakijwanich, X. H. You, S.H. Chen, S. R. Zhang, C. Hou, Shuibin Lin, Lu Zhang, L. Feng, Xuelong Wang, S. Wu, X. X. Zhai, Xuliang Chen, C. X. Liu, L. L. Ma, Y. He, Z. X. Fan, Z. Y. You, F. R. Zhu, Y. W. Bao, Qie Sun, Yi Chen, X. G. Wang, Yi Zhang, Xiang-Yu Wang, D. H. Huang, R. Zhou, Hao Zhou, H. Zhu, X. J. Bi, D. della Volpe, Tao Zeng, T. L. Chen, Bin Ma, J. S. Wang, Cunguo Wang, L. X. Zhang, Shujuan Liu, N. Yin, N. Cheng, D. Bastieri, X. H. Cui, Cheng Li, W. J. Long, Shengxue Zhang, Axikegu, Li Zhang, G. H. Gong, Danzengluobu, M. H. Gu, Y. H. Yu, Jie Zhang, Y. Z. Fan, Dong Liu, C. Y. Wu, J. T. Cai, Long Chen, Y. Zheng, L. Q. Yin, Y. M. Ye, J. Y. Yang, B D Ettorre Piazzoli, David Ruffolo, Z. B. Sun, Cheng Guang Zhu, X. H. Ma, M. Heller, K. Li, Z. J. Jiang, J. Liu, Yong Zhang, Minghui Liu, R. N. Wang, and Jinyao Liu

Subjects
Physics, Multidisciplinary, Photon, COSMIC cancer database, Proton, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Electron, Astrophysics, 01 natural sciences, Galaxy, Supernova, Crab Nebula, Pulsar, 0103 physical sciences, 010306 general physics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 1015 electronvolts) indicates the existence of the so-called PeVatrons—cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays1. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. 2). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane3–6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators. Observations of γ-rays with energies up to 1.4 PeV find that 12 sources in the Galaxy are PeVatrons, one of which is the Crab Nebula.

Published
2021
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16. Probing Mo93m Isomer Depletion with an Isomer Beam

Author

S. Guo, B. Ding, X. H. Zhou, Y. B. Wu, J. G. Wang, S. W. Xu, Y. D. Fang, C. M. Petrache, E. A. Lawrie, Y. H. Qiang, Y. Y. Yang, H. J. Ong, J. B. Ma, J. L. Chen, F. Fang, Y. H. Yu, B. F. Lv, F. F. Zeng, Q. B. Zeng, H. Huang, Z. H. Jia, C. X. Jia, W. Liang, Y. Li, N. W. Huang, L. J. Liu, Y. Zheng, W. Q. Zhang, A. Rohilla, Z. Bai, S. L. Jin, K. Wang, F. F. Duan, G. Yang, J. H. Li, J. H. Xu, G. S. Li, M. L. Liu, Z. Liu, Z. G. Gan, M. Wang, and Y. H. Zhang

Subjects
General Physics and Astronomy
Published
2022
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19. Probing ^{93m}Mo Isomer Depletion with an Isomer Beam

Author

S, Guo, B, Ding, X H, Zhou, Y B, Wu, J G, Wang, S W, Xu, Y D, Fang, C M, Petrache, E A, Lawrie, Y H, Qiang, Y Y, Yang, H J, Ong, J B, Ma, J L, Chen, F, Fang, Y H, Yu, B F, Lv, F F, Zeng, Q B, Zeng, H, Huang, Z H, Jia, C X, Jia, W, Liang, Y, Li, N W, Huang, L J, Liu, Y, Zheng, W Q, Zhang, A, Rohilla, Z, Bai, S L, Jin, K, Wang, F F, Duan, G, Yang, J H, Li, J H, Xu, G S, Li, M L, Liu, Z, Liu, Z G, Gan, M, Wang, and Y H, Zhang

Abstract

The isomer depletion of ^{93m}Mo was recently reported [Chiara et al., Nature (London) 554, 216 (2018)NATUAS0028-083610.1038/nature25483] as the first direct observation of nuclear excitation by electron capture (NEEC). However, the measured excitation probability of 1.0(3)% is far beyond the theoretical expectation. In order to understand the inconsistency between theory and experiment, we produce the ^{93m}Mo nuclei using the ^{12}C(^{86}Kr,5n) reaction at a beam energy of 559 MeV and transport the reaction residues to a detection station far away from the target area employing a secondary beam line. The isomer depletion is expected to occur during the slowdown process of the ions in the stopping material. In such a low γ-ray background environment, the signature of isomer depletion is not observed, and an upper limit of 2×10^{-5} is estimated for the excitation probability. This is consistent with the theoretical expectation. Our findings shed doubt on the previously reported NEEC phenomenon and highlight the necessity and feasibility of further experimental investigations for reexamining the isomer depletion under low γ-ray background.

Published
2022

23. Charge Loss Correction in the Silicon-Tungsten Tracker-Converter for Proton-Helium Charge Identification in the DAMPE Detector

Author

Zi Qing Xia, F. C. T. Barbato, M. Di Santo, Kai Kai Duan, D. Mo, A. Ruina, A. Kotenko, Tao Ma, Yong Jie Zhang, Yan Fang Wang, M. N. Mazziotta, H. Su, Yong Qiang Zhang, A. Parenti, Guang Shun Huang, Z. X. Dong, Meng Su, Hui Jun Yao, Jinglai Duan, Xiao Yuan Huang, Yang Haibo, X. J. Teng, Qi Ding, F. de Palma, J. N. Rao, Chang Yi Zhou, Zhi Yong Zhang, J. J. Zang, Lei Feng, Chang Qing Feng, Hao Ran Sun, J. J. Wei, Lihui Wu, Huaguang Wang, Yi Zhang, Yao Ming Liang, Xu Pan, D. D'Urso, Zhan Fang Chen, Yan Zhang, Maria Ionica, Jie Kong, E. Casilli, W. H. Shen, Y. Y. Huang, Shi Jun Lei, Cong Zhao, L. Silveri, P. Fusco, A. De Benedittis, M. S. Cai, Deng Yi Chen, F. Alemanno, Peng Xiong Ma, Z. T. Shen, I. De Mitri, D. Droz, Yang Liu, Q. An, Xiao Yong Ma, W. X. Peng, M. Stolpovskiy, M. Y. Cui, Zi Zong Xu, Sheng Xia Zhang, Jin Zhou Wang, K. Gong, Yi-Zhong Fan, Xiang Li, Hong Yun Zhao, M. M. Salinas, Xiao Yang Niu, Ya Peng Zhang, R. Qiao, Z. Y. Sun, G. Z. Shang, Shuang Xue Han, E. Catanzani, Shu Xin Wang, Wen Hao Li, Peng Yang, Di Wu, En Heng Xu, T. S. Cui, A. Surdo, Jian Wu, Jin Chang, P. Azzarello, Chuan Yue, Ya Qing Yang, Shen Wang, Xin Wu, Fang Fang, Kun Fang, Chuan Ning Luo, Maksym Deliyergiyev, F. Gargano, Jian Hua Guo, D. Kyratzis, Y. Z. Gong, Qiang Yuan, X. Y. Peng, S. B. Liu, Xian Qiang Li, M. M. Ma, Y. F. Wei, Y. H. Yu, Yun Long Zhang, C. Liu, Xiao Lian Wang, V. Gallo, W. Zhang, Wei Jiang, Zhe Zhang, C. Perrina, G. F. Xue, Ying Wang, Yu Xing Cui, Sha Sha Wu, Giacinto Donvito, Y. M. Hu, F. Loparco, J. L. Chen, Hao Ting Dai, L. G. Wang, Dong Ya Guo, Guan Wen Yuan, Hao Liu, Jie Liu, G. Marsella, Andrii Tykhonov, Hai Tao Xu, Xiao Jun Bi, Min Gao, Zun Lei Xu, Zhao Qiang Shen, Xun Feng Zhao, Zhi Hui Xu, Da Ming Wei, Wei Liang Li, P. Bernardini, Tie Kuang Dong, Jing Xing Song, R. R. Fan, and Yuan Zhu Wang

Subjects
Physics, Nuclear physics, chemistry, Proton, Physics::Instrumentation and Detectors, Dark matter, Detector, Gamma ray, chemistry.chemical_element, Particle, Charge (physics), Helium, Ion
Abstract

The DArk Matter Particle Explorer (DAMPE) is a satellite-borne experiment, in operation since 2015, aimed at studying high-energy gamma rays and cosmic nuclei fluxes. Of the various sub-detectors in the DAMPE payload, the Silicon-Tungsten tracKer-converter (STK) plays a significant role in the charge measurement of incoming ions. Depending on the angle of inclination of the impinging particle and its position of impact on these strips, the collected charge can spread between the strips which results in some fractional signal loss. The $\eta$ variable is used to identify this spread of charge across the strips and correct for the associated charge loss. This brings us closer to accurate determination of particle charge which is crucial for ensuring a good discrimination between particles. The $\eta$-correction is, therefore, expected to play an important role in the determination of heavy ions by the DAMPE detector. It has helped reduce the proton background for the helium identification in STK by a factor of 1.5 for MIP tracks. It has been sucessfully applied to carbon nuclei and its application to heavier nuclei is currently being studied.

Published
2021
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24. Performance of the DAMPE silicon-tungsten tracker during the first 5 years of in-orbit operations

Author

Peng Yang, Jinglai Duan, Xian Qiang Li, Zun Lei Xu, Zhi Yong Zhang, Xiang Li, Zhao Qiang Shen, Xun Feng Zhao, Yang Haibo, Z. X. Dong, M. M. Ma, J. N. Rao, X. J. Teng, Ying Wang, Yang Liu, Guan Wen Yuan, Jin Zhou Wang, Qi Ding, Zhi Hui Xu, Kai Kai Duan, Z. Y. Sun, G. Marsella, Yu Xing Cui, D. Mo, J. J. Zang, Andrii Tykhonov, Da Ming Wei, W. H. Shen, Qiang Yuan, Giacinto Donvito, Y. H. Yu, Yun Long Zhang, P. Azzarello, Huaguang Wang, I. Di Santo, M. S. Cai, Hai Tao Xu, Yan Fang Wang, Di Wu, Chuan Ning Luo, Q. An, Wei Liang Li, S. B. Liu, Z. T. Shen, Xiao Jun Bi, Min Gao, A. Kotenko, Guang Shun Huang, Xiao Yuan Huang, Tie Kuang Dong, Jian Wu, Sha Sha Wu, W. X. Peng, Zhan Fang Chen, T. S. Cui, Ya Qing Yang, Tao Ma, Fang Fang, Jing Xing Song, K. Gong, Zi Zong Xu, R. R. Fan, F. de Palma, Yong Jie Zhang, Jian Hua Guo, Y. F. Wei, Maria Munoz Salinas, F. Loparco, Yan Zhang, M. N. Mazziotta, H. Su, En Heng Xu, C. Liu, Xiao Lian Wang, A. Surdo, Yi Zhang, J. L. Chen, G. Z. Shang, Shuang Xue Han, Chang Qing Feng, W. Zhang, Y. Z. Gong, Ya Peng Zhang, I. De Mitri, Lei Feng, Wei Jiang, Xiao Yong Ma, R. Qiao, Shu Xin Wang, Deng Yi Chen, Zhe Zhang, Li Bo Wu, Xiao Yang Niu, G. F. Xue, X. Y. Peng, Zi Qing Xia, D. Droz, F. Alemanno, Jin Chang, Yao Ming Liang, E. Catanzani, Wen Hao Li, Xin Wu, L. Silveri, Chang Yi Zhou, Yuan Zhu Wang, F. C. T. Barbato, F. Gargano, Chuan Yue, Yong Qiang Zhang, Yi-Zhong Fan, Meng Su, D. D'Urso, Dampe, Y. Y. Huang, Kun Fang, Maksym Deliyergiyev, P. Fusco, Shi Jun Lei, D. Kyratzis, A. De Benedittis, Peng Xiong Ma, P. Bernardini, A. Parenti, M. Stolpovskiy, M. Y. Cui, A. Ruina, Hui Jun Yao, Hao Ran Sun, J. J. Wei, Shen Wang, Hong Yun Zhao, Maria Ionica, Jie Kong, E. Casilli, Sheng Xia Zhang, Y. M. Hu, Hao Ting Dai, C. Perrina, L. G. Wang, Dong Ya Guo, Hao Liu, Jie Liu, Xu Pan, and Cong Zhao

Subjects
Physics, Optics, Physics::Instrumentation and Detectors, business.industry, Detector, Orbit (dynamics), Calibration, Satellite, Tracking (particle physics), business, Particle detector, Noise (radio), Charged particle
Abstract

Since its launch, in December 2015, the satellite-based DAMPE (DArk Matter Particle Explorer) particle detector is taking data smoothly. The Silicon-Tungsten tracKer-converter (STK) of DAMPE consists of six tracking planes (6x, 6y) of single-sided silicon micro-strip detectors mounted on seven support trays. The STK is able to measure the charge and precisely reconstruct the track of traversing charged particles. Tungsten plates (1 mm thick) are integrated in the second, third and fourth tray from the top to serve as $\gamma \rightarrow e^+e^−$ converters. Commissioned rapidly after the launch, the STK is running extremely well since then. The STK in-orbit calibration and performance during its first more than 5 years of operation, including the noise behaviour and the thermal and mechanical stability, are presented in this contribution.

Published
2021
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25. On-orbit performance of the DAMPE BGO calorimeter

Author

D. Droz, Yang Liu, Jin Zhou Wang, Guan Wen Yuan, G. Marsella, Zun Lei Xu, Zhao Qiang Shen, Xun Feng Zhao, Zhi Hui Xu, Ya Peng Zhang, Qiang Yuan, S. B. Liu, Andrii Tykhonov, Hai Tao Xu, Y. M. Hu, Xiao Jun Bi, Min Gao, K. Gong, Da Ming Wei, Yi Zhang, Chuan Yue, G. Z. Shang, Shuang Xue Han, Hao Ting Dai, Y. F. Wei, Shu Xin Wang, Jinglai Duan, Chang Qing Feng, Maria Ionica, Jie Kong, E. Casilli, Zi Qing Xia, Z. X. Dong, Wei Liang Li, P. Azzarello, M. Di Santo, Yao Ming Liang, Fang Fang, Yuan Zhu Wang, Y. Y. Huang, F. C. T. Barbato, Tie Kuang Dong, Peng Xiong Ma, P. Fusco, L. Silveri, J. J. Zang, Huaguang Wang, L. G. Wang, X. J. Teng, M. Y. Cui, Sha Sha Wu, C. Liu, Xiao Lian Wang, V. Gallo, W. Zhang, Dong Ya Guo, Yi-Zhong Fan, Tao Ma, Chuan Ning Luo, F. Loparco, Jing Xing Song, W. H. Shen, R. R. Fan, Yong Jie Zhang, M. S. Cai, Shen Wang, J. L. Chen, Hao Liu, Deng Yi Chen, J. N. Rao, M. N. Mazziotta, H. Su, Jie Liu, Yan Zhang, Z. T. Shen, Hui Jun Yao, Yifeng Wei, Y. H. Yu, P. Bernardini, W. X. Peng, Yun Long Zhang, A. Parenti, Wei Jiang, Yong Qiang Zhang, Meng Su, Kai Kai Duan, Zhe Zhang, D. Mo, F. Alemanno, Hao Ran Sun, Xiao Yang Niu, Peng Yang, Zhan Fang Chen, A. Ruina, J. J. Wei, Lihui Wu, Ying Wang, Xiao Yuan Huang, Yan Fang Wang, G. F. Xue, Sheng Xia Zhang, Di Wu, F. de Palma, Kun Fang, Zi Zong Xu, Chang Yi Zhou, Xin Wu, Yu Xing Cui, D. D'Urso, C. Perrina, D. Kyratzis, Yang Haibo, Q. An, Xian Qiang Li, Jian Wu, En Heng Xu, Shi Jun Lei, M. M. Ma, Jian Hua Guo, Qi Ding, Xu Pan, Giacinto Donvito, Ya Qing Yang, Jin Chang, Z. Y. Sun, R. Qiao, Cong Zhao, F. Gargano, I. De Mitri, Hong Yun Zhao, T. S. Cui, Xiao Yong Ma, Zhi Yong Zhang, E. Catanzani, Y. Z. Gong, Wen Hao Li, A. Surdo, X. Y. Peng, Dampe, M. M. Salinas, Guang Shun Huang, Lei Feng, A. De Benedittis, M. Stolpovskiy, A. Kotenko, and Xiang Li

Subjects
Physics, Scintillation, Range (particle radiation), Calorimeter (particle physics), Physics::Instrumentation and Detectors, Payload, business.industry, Detector, Dark matter, Optics, High Energy Physics::Experiment, Satellite, Optical filter, business
Abstract

The DArk Matter Particle Explorer (DAMPE) is the first Chinese cosmic-ray direct detection experiment. It has been operating smoothly on-orbit since its successful launch at the end of 2015. Currently, its sub-detectors and the satellite are in good working order. The DAMPE payload employs a BGO Calorimeter for energy measurements, trigger and e/p identification. The calorimeter is constructed of 308 BGO crystals, and PMTs are coupled to the crystals with optical filters to readout scintillation light. In this work, we present the status and performance of the calorimeter, including status of detector units, energy measurement, especially in TeV range, detector endurance, and long term performance in a duration of 65 months.

Published
2021
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26. Analyzing the Fermi Bubbles with DArk Matter Particle Explorer

Author

Z. X. Dong, J. N. Rao, D. Droz, Yang Liu, Jin Zhou Wang, Xun Feng Zhao, Zhi Hui Xu, Da Ming Wei, Yong Qiang Zhang, Meng Su, Zhan Fang Chen, Yuan Zhu Wang, Wei Liang Li, F. Alemanno, Yan Zhang, Yi Zhang, P. Azzarello, Guang Shun Huang, Tie Kuang Dong, Sha Sha Wu, A. Surdo, Jinglai Duan, Zhao-Qiang Shen, F. Loparco, J. L. Chen, Zi Qing Xia, I. De Mitri, Xiao Yong Ma, Zhi Yong Zhang, P. Bernardini, Jing Xing Song, F. C. T. Barbato, R. R. Fan, Z. Y. Sun, Yong Jie Zhang, Di Wu, Yang Haibo, Shi Jun Lei, Chuan Ning Luo, Y. H. Yu, Yun Long Zhang, Y. M. Hu, C. Liu, Xiao Lian Wang, M. N. Mazziotta, H. Su, K. Gong, Jian Wu, E. Catanzani, V. Gallo, W. Zhang, Wen Hao Li, Qi Ding, Ya Qing Yang, T. S. Cui, G. Z. Shang, Shuang Xue Han, Wei Jiang, Zhe Zhang, Zi Zong Xu, Xiang Li, G. F. Xue, Shu Xin Wang, Guan Wen Yuan, Xian Qiang Li, M. M. Ma, Hao Ting Dai, Ying Wang, Tao Ma, D. Mo, Hong Yun Zhao, G. Marsella, Andrii Tykhonov, Hai Tao Xu, Xiao Jun Bi, Min Gao, Yu Xing Cui, Yao Ming Liang, L. Silveri, Giacinto Donvito, Yan Fang Wang, L. G. Wang, Jin Chang, F. Gargano, Y. F. Wei, M. M. Salinas, Dong Ya Guo, Y. Z. Gong, Xu Pan, Xin Wu, Hao Liu, Jie Liu, X. Y. Peng, Cong Zhao, M. S. Cai, Jian Hua Guo, A. Parenti, Deng Yi Chen, Chang Qing Feng, Peng Xiong Ma, W. X. Peng, Ya Peng Zhang, En Heng Xu, A. Ruina, M. Y. Cui, Chang Yi Zhou, D. D'Urso, C. Perrina, J. J. Zang, Huaguang Wang, I. Di Santo, Chuan Yue, Shen Wang, Z. Xu, A. De Benedittis, Kun Fang, Yi-Zhong Fan, Xiao Yuan Huang, Kai-Kai Duan, D. Kyratzis, F. de Palma, M. Stolpovskiy, Qiang Yuan, S. B. Liu, Y. Y. Huang, P. Fusco, Lei Feng, A. Kotenko, Li Bo Wu, Xiao Yang Niu, Fang Fang, X. J. Teng, W. H. Shen, Z. T. Shen, Q. An, R. Qiao, Hui Jun Yao, Hao Ran Sun, J. J. Wei, Maria Ionica, Jie Kong, E. Casilli, Sheng Xia Zhang, and Peng Yang

Subjects
Physics, Range (particle radiation), High energy particle, Photon, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, Galactic Center, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galactic plane, Astrophysics::Galaxy Astrophysics, Fermi Gamma-ray Space Telescope
Abstract

The Fermi bubbles are two large structures above and below the Galactic Plane. They are first discovered by Fermi-LAT and thought to be related to the jet or the wind from the Galactic center. The DArk Matter Particle Explorer (DAMPE) is a space-borne high energy particle telescope aiming at measuring cosmic rays and photons in a broad energy range. In this work, we use 4.8 years of DAMPE photon data to search for the emission from the Fermi Bubbles. We calculate the TS values of the lobes and the significance of its curved spectrum. The obtained spectral parameters are then compared with those from the Fermi-LAT. We also search for the emission from the cocoon in the southeast part of lobes. Since the Galactic diffuse emission (GDE) model is a major source of systematic uncertainty, we also switch to the GDE models calculated with Galprop and evaluate the influence.

Published
2021
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27. Measurement of the Boron to Carbon Flux Ratio in Cosmic Rays with the DAMPE Experiment

Author

Jinglai Duan, Peng Yang, Xian Qiang Li, Maria Ionica, Jie Kong, E. Casilli, Wei Liang Li, M. M. Ma, Yan Zhang, Ya Peng Zhang, Y. Z. Gong, Z. X. Dong, Y. M. Hu, Yi Zhang, Chang Qing Feng, Tie Kuang Dong, K. Gong, X. Y. Peng, G. Z. Shang, Shuang Xue Han, Q. An, Hao Ting Dai, Chuan Yue, Shu Xin Wang, P. Azzarello, Qiang Yuan, D. Kyratzis, Y. Y. Huang, Yuan Zhu Wang, S. B. Liu, Xin Wu, Kai Kai Duan, Y. H. Yu, En Heng Xu, D. Mo, Yun Long Zhang, Jing Xing Song, P. Fusco, Yong Jie Zhang, R. Qiao, A. Parenti, R. R. Fan, C. Perrina, Hui Jun Yao, J. N. Rao, Y. F. Wei, M. M. Salinas, Yan Fang Wang, M. N. Mazziotta, H. Su, Zun Lei Xu, J. J. Zang, A. Ruina, Deng Yi Chen, Hao Ran Sun, Zhao Qiang Shen, Xun Feng Zhao, Huaguang Wang, J. J. Wei, L. G. Wang, Dong Ya Guo, I. Di Santo, Zhi Hui Xu, Yi-Zhong Fan, P. Bernardini, Tao Ma, Hao Liu, Jie Liu, Guang Shun Huang, Ying Wang, Zhan-Fang Chen, Sha Sha Wu, Dampe, Zi Zong Xu, Yu Xing Cui, Chuan Ning Luo, Sheng Xia Zhang, Yang Haibo, Giacinto Donvito, Xiao Yuan Huang, Yao Ming Liang, F. Loparco, Li-Bo Wu, J. L. Chen, Da Ming Wei, Qi Ding, Zhan Fang Chen, F. de Palma, L. Silveri, Guan Wen Yuan, Kun Fang, D. Droz, Yang Liu, G. Marsella, Andrii Tykhonov, Jin Zhou Wang, Hai Tao Xu, Xiang Li, Xiao Jun Bi, Min Gao, Jin Chang, F. Gargano, Zhi Yong Zhang, Fang Fang, Peng Xiong Ma, Di Wu, Jian Wu, M. Y. Cui, Ya Qing Yang, Li Bo Wu, Xiao Yang Niu, X. J. Teng, W. H. Shen, Z. T. Shen, Xu Pan, Cong Zhao, Ming-Yang Cui, M. S. Cai, Lei Feng, W. X. Peng, Jian Hua Guo, I. De Mitri, Xiao Yong Ma, Zi Qing Xia, A. De Benedittis, E. Catanzani, Wen Hao Li, F. C. T. Barbato, M. Stolpovskiy, A. Kotenko, Shen Wang, A. Surdo, Hong Yun Zhao, F. Alemanno, C. Liu, Xiao Lian Wang, V. Gallo, W. Zhang, Z. Y. Sun, Chang Yi Zhou, Wei Jiang, D. D'Urso, T. S. Cui, Shi Jun Lei, Zhe Zhang, G. F. Xue, Yong Qiang Zhang, and Meng Su

Subjects
Physics, Nuclear physics, Range (particle radiation), High energy particle, chemistry, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, Detector, chemistry.chemical_element, Particle, Cosmic ray, Boron, Carbon
Abstract

The DArk Matter Particle Explorer (DAMPE), a space-based high energy particle detector, has been operated on-orbit for more than five years. The large geometric factor and good charge resolution enable DAMPE to have very good potential to measure cosmic-rays up to 100 TeV. Knowledge of the boron to carbon (B/C) flux ratio is very important in understanding the prop- agation of cosmic rays, especially in TeV energy range. In this contribution, the latest progress of the B/C flux ratio analysis based on the flight data collected by DAMPE during the 5 years of operation, is presented.

Published
2021
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28. Discovery of a new $\gamma$-ray source LHAASO J0341+5258 with emission up to 200TeV

Author

Zhengguo Cao, L. Feng, Xufang Li, Zebo Tang, Jun-Jie Wei, C. Y. Wu, Jia Zhang, L. X. Bai, Yi Zhang, H. K. Lv, Jixia Li, L. L. Yang, Z. X. Wang, M. Zha, Y. M. Ye, X. H. Ma, L. P. Wang, X. G. Wang, Donglian Xu, X. L. Guo, Y. A. Han, Binyu Zhao, Yun-Feng Liang, Houdun Zeng, Zhe Li, Y. Su, B. Z. Dai, Z. G. Dai, Jinmei Liu, B. D'Ettorre Piazzoli, Z. G. Yao, Y. Zheng, W. X. Wu, M. L. Chen, Jianeng Zhou, Hefan Li, W. Wang, P. Pattarakijwanich, Rong Xu, J. J. Xia, X. X. Zhai, J. Fang, F. R. Zhu, Qie Sun, Yi Chen, H. B. Li, G. M. Xiang, W. Liu, B. Y. Pang, S. Wu, X. L. Ji, R. Lu, K. Li, Y. J. Bi, H. D. Liu, Y. D. Cheng, Bo Zhang, L. Q. Yin, Hanzhong Zhang, C. X. Liu, D. della Volpe, Y. D. Cui, Kun Fang, Yugang Zhang, E. W. Liang, Ping Zhou, Z. J. Jiang, Y. J. Wei, J. Liu, Yong Zhang, Duo Yan, Yu. V. Stenkin, S. L. He, Y. P. Wang, Z. X. Liu, D. H. Huang, R. N. Wang, S. M. Liu, F. Ji, V. Rulev, Y. Z. Li, H. H. He, H. Zhu, C. Hou, Zheng Wang, B. Q. Ma, Y. C. Nan, L. Xue, Jun Liu, Lu Zhang, H. Y. Jia, D. M. Wei, V. I. Stepanov, E. S. Chen, Sina Chen, K. J. Zhu, Y. Q. Qi, Fulai Guo, J. Y. Shi, Minghui Liu, Yi Liu, J. B. Zhao, H. Wang, X. F. Wu, Zhen Wang, Z. X. Fan, Z. Y. You, Shi-Qi Hu, J. Y. Yang, N. Cheng, Z. K. Zeng, C. D. Gao, X. H. You, Long Gao, H. C. Song, Lei Zhao, D.A. Kuleshov, X. X. Zhou, Q. Yuan, B. M. Chen, Ruizhi Yang, X. N. Sun, Shengxue Zhang, Danzengluobu, J. F. Chang, S. P. Zhao, H. Liu, J.W. Xia, W. Gao, G. C. Xiao, Felix Aharonian, Xinbo He, K. Jiang, Pak-Hin Thomas Tam, H. C. Li, Y. Wang, Y. Z. Fan, Dong Liu, Y. W. Bao, P. F. Zhang, X. J. Bi, H. N. He, T. L. Chen, L. Z. Zhao, X. J. Hu, R. Zhou, Ying Zhang, Oleg Shchegolev, Junjie Mao, Y. Q. Guo, F. Y. Li, K. Levochkin, J. T. Cai, X. D. Sheng, Cong Li, X. Zuo, B. B. Li, Long Chen, Yunchao Liu, H. L. Dai, T. Wen, S. W. Cui, S. Z. Chen, David Ruffolo, Y. M. Xing, H. R. Wu, Liang Chen, Xiang-Kun Dong, S. Hu, J. Y. Liu, X. Y. Huang, P. P. Zhang, X. H. Cui, Minghao Qi, Z. B. Sun, Y. Bai, Z. Y. Pei, Cheng Guang Zhu, Yuan-Hao Wang, Zhuo Li, Warit Mitthumsiri, H. M. Zhang, Q. An, Y. H. Yao, W. H. Huang, H. Zhou, W. J. Long, Binbin Zhou, Li-Sheng Geng, R. Liu, Xiang Zhang, J. G. Guo, J. W. Zhang, S. R. Zhang, Wenwu Tian, L. L. Ma, Q. Gao, C. F. Feng, Jiangang He, J. S. Wang, Cunguo Wang, Y. L. Xin, Z. C. Huang, H. B. Hu, N. Yin, B. Q. Qiao, Xin Li, Cheng Li, Jiajun Qin, M. H. Gu, Boyang Wang, Rui Zhang, H. B. Xiao, W. Zeng, L. X. Zhang, S. H. Feng, M. M. Ge, Axikegu, Yonggang Wang, M. J. Chen, Zhao-Qi Wang, Y. Y. Guo, Li Zhang, G. H. Gong, Zhe Cao, Y. K. Hor, Y. H. Yu, T. Montaruli, Jian Wang, Chiming Jin, Z. Min, Xuelong Wang, G. G. Xin, Kai-Kai Duan, D. Bastieri, Y. L. Feng, T. Ke, S. J. Lin, X. T. Huang, L. Y. Wang, B. Liu, Jingzhi Yan, Bingshui Gao, Xiang-Yu Wang, Yulong Li, Tao Zeng, Xuliang Chen, Y. He, C. W. Yang, Jun-Hui Fan, Q. B. Gou, W. L. Li, D. X. Xiao, Qizhi Huang, J. Chen, Xiao-Hu Zhang, H. Cai, M. J. Yang, S. Q. Xi, Hong-Guang Wang, Alejandro Sáiz, Q. H. Chen, S. B. Yang, Fan Yang, A. Masood, F. Zheng, Lang Shao, and M. Heller

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Gamma ray, Flux, Astronomy and Astrophysics, Astrophysics, Galactic plane, Crab Nebula, Pulsar, Space and Planetary Science, Angular diameter, High Energy Physics::Experiment, Supernova remnant, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics
Abstract

We report the discovery of a new unidentified extended $\gamma$-ray source in the Galactic plane named LHAASO J0341+5258 with a pre-trial significance of 8.2 standard deviations above 25 TeV. The best fit position is R.A.$=55.34^{\circ}\pm0.11^{\circ}$ and Dec$=52.97^{\circ}\pm0.07^{\circ}$. The angular size of LHAASO J0341+5258 is $0.29^\circ \pm 0.06^\circ_{stat} \pm0.02^\circ_{sys}$. The flux above 25 TeV is about $20\%$ of the flux of Crab Nebula. Although a power-law fit of the spectrum from 10 TeV to 200 TeV with the photon index $\alpha=2.98 \pm 0.19_{stat} \pm 0.02_{sys}$ is not excluded, the LHAASO data together with the flux upper limit at 10 GeV set by the Fermi LAT observation, indicate a noticeable steepening of an initially hard power-law spectrum %($\alpha \leq 1.75$) spectrum with a cutoff at $\approx 50$ TeV. We briefly discuss the origin of UHE gamma-rays. The lack of an energetic pulsar and a young SNR inside or in the vicinity of LHAASO J0341+5258 challenge, but do not exclude both the leptonic and hadronic scenarios of gamma-ray production., Comment: Accepted by APJL

Published
2021

29. Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Author

Zhen, Cao, F, Aharonian, Q, An, Axikegu, L X, Bai, Y X, Bai, Y W, Bao, D, Bastieri, X J, Bi, Y J, Bi, H, Cai, J T, Cai, Zhe, Cao, J, Chang, J F, Chang, B M, Chen, E S, Chen, J, Chen, Liang, Chen, Long, Chen, M J, Chen, M L, Chen, Q H, Chen, S H, Chen, S Z, Chen, T L, Chen, X L, Chen, Y, Chen, N, Cheng, Y D, Cheng, S W, Cui, X H, Cui, Y D, Cui, B D'Ettorre, Piazzoli, B Z, Dai, H L, Dai, Z G, Dai, Danzengluobu, D, Della Volpe, X J, Dong, K K, Duan, J H, Fan, Y Z, Fan, Z X, Fan, J, Fang, K, Fang, C F, Feng, L, Feng, S H, Feng, Y L, Feng, B, Gao, C D, Gao, L Q, Gao, Q, Gao, W, Gao, M M, Ge, L S, Geng, G H, Gong, Q B, Gou, M H, Gu, F L, Guo, J G, Guo, X L, Guo, Y Q, Guo, Y Y, Guo, Y A, Han, H H, He, H N, He, J C, He, S L, He, X B, He, Y, He, M, Heller, Y K, Hor, C, Hou, X, Hou, H B, Hu, S, Hu, S C, Hu, X J, Hu, D H, Huang, Q L, Huang, W H, Huang, X T, Huang, X Y, Huang, Z C, Huang, F, Ji, X L, Ji, H Y, Jia, K, Jiang, Z J, Jiang, C, Jin, T, Ke, D, Kuleshov, K, Levochkin, B B, Li, Cheng, Li, Cong, Li, F, Li, H B, Li, H C, Li, H Y, Li, Jian, Li, Jie, Li, K, Li, W L, Li, X R, Li, Xin, Li, Y, Li, Y Z, Li, Zhe, Li, Zhuo, Li, E W, Liang, Y F, Liang, S J, Lin, B, Liu, C, Liu, D, Liu, H, Liu, H D, Liu, J, Liu, J L, Liu, J S, Liu, J Y, Liu, M Y, Liu, R Y, Liu, S M, Liu, W, Liu, Y, Liu, Y N, Liu, Z X, Liu, W J, Long, R, Lu, H K, Lv, B Q, Ma, L L, Ma, X H, Ma, J R, Mao, A, Masood, Z, Min, W, Mitthumsiri, T, Montaruli, Y C, Nan, B Y, Pang, P, Pattarakijwanich, Z Y, Pei, M Y, Qi, Y Q, Qi, B Q, Qiao, J J, Qin, D, Ruffolo, V, Rulev, A, Sáiz, L, Shao, O, Shchegolev, X D, Sheng, J R, Shi, H C, Song, Yu V, Stenkin, V, Stepanov, Y, Su, Q N, Sun, X N, Sun, Z B, Sun, P H T, Tam, Z B, Tang, W W, Tian, B D, Wang, C, Wang, H, Wang, H G, Wang, J C, Wang, J S, Wang, L P, Wang, L Y, Wang, R N, Wang, W, Wang, X G, Wang, X J, Wang, X Y, Wang, Y, Wang, Y D, Wang, Y J, Wang, Y P, Wang, Z H, Wang, Z X, Wang, Zhen, Wang, Zheng, Wang, D M, Wei, J J, Wei, Y J, Wei, T, Wen, C Y, Wu, H R, Wu, S, Wu, W X, Wu, X F, Wu, S Q, Xi, J, Xia, J J, Xia, G M, Xiang, D X, Xiao, G, Xiao, H B, Xiao, G G, Xin, Y L, Xin, Y, Xing, D L, Xu, R X, Xu, L, Xue, D H, Yan, J Z, Yan, C W, Yang, F F, Yang, J Y, Yang, L L, Yang, M J, Yang, R Z, Yang, S B, Yang, Y H, Yao, Z G, Yao, Y M, Ye, L Q, Yin, N, Yin, X H, You, Z Y, You, Y H, Yu, Q, Yuan, H D, Zeng, T X, Zeng, W, Zeng, Z K, Zeng, M, Zha, X X, Zhai, B B, Zhang, H M, Zhang, H Y, Zhang, J L, Zhang, J W, Zhang, L X, Zhang, Li, Zhang, Lu, Zhang, P F, Zhang, P P, Zhang, R, Zhang, S R, Zhang, S S, Zhang, X, Zhang, X P, Zhang, Y F, Zhang, Y L, Zhang, Yi, Zhang, Yong, Zhang, B, Zhao, J, Zhao, L, Zhao, L Z, Zhao, S P, Zhao, F, Zheng, Y, Zheng, B, Zhou, H, Zhou, J N, Zhou, P, Zhou, R, Zhou, X X, Zhou, C G, Zhu, F R, Zhu, H, Zhu, K J, Zhu, and X, Zuo

Subjects
General Physics and Astronomy
Abstract

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

Published
2021

30. Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

Author

Fengtao Zhang, Y. F. Wang, Y. Y. Huang, Xiangpeng Guo, Jinfei Wu, D. Droz, J. N. Rao, Jinglai Duan, Yang Haibo, C. Liu, D. M. Wei, Zongye Zhang, X. Y. Ma, P. Azzarello, P. Fusco, Z. Y. Sun, Niu Xiaoyang, I. De Mitri, W. Zhang, Cihang Luo, C. Q. Feng, Yu Xing Cui, X. X. Li, M. S. Cai, Z.-Q. Shen, G. Marsella, X. L. Wang, S. Wang, F. Loparco, Guan Wen Yuan, Y. F. Wei, Jin Chang, Y. J. Zhang, Giacinto Donvito, W. X. Peng, J. L. Chen, Q. An, S. B. Liu, S. C. Wen, F. Gargano, Xiulian Pan, Y. Z. Gong, Cang Zhao, Yuqing Fan, T. S. Cui, H. T. Xu, A. De Benedittis, E. Catanzani, M. M. Salinas, Y. H. Yu, Zhao-Min Wang, Yun Long Zhang, Andrii Tykhonov, Wei Liu, Dingsong Wu, Zhenyu Zhang, Yifan Yang, G. F. Xue, Fang Fang, Pengtao Yang, M. Di Santo, R. Qiao, Yaohui Zhang, Xian Qiang Li, X. J. Bi, Chuan Yue, Min Gao, Z. Q. Xia, Shumei Wu, X. Y. Peng, M. M. Ma, Wenhan Jiang, J. Z. Wang, F. C. T. Barbato, M. Stolpovskiy, Hengchang Liu, F. Alemanno, P. Bernardini, J. J. Wei, Lihui Wu, Yujuan Liu, J. Liu, Yao Ming Liang, Z. Xu, A. Parenti, L. Feng, Yun-Zhi Zhang, A. Ruina, D. Mo, M. Y. Cui, Xin Wu, L. Silveri, Jun-jun Guo, Yu-Sa Wang, Hong Yun Zhao, W. Li, Hu-Rong Yao, Jinyuo Song, Z. Z. Xu, Z. X. Dong, Yan Fang Wang, Kun Fang, Y. Zhang, A. D'Amone, H. Su, Meng Su, A. Kotenko, Maria Ionica, Jie Kong, Shi-Jun Lei, Sheng Xia Zhang, Q. Yuan, Guangshun Huang, R. R. Fan, Peng-Xiong Ma, Xun Feng Zhao, Zhi Hui Xu, S.X. Li, A. Surdo, Yu-Xuan Zhu, X. J. Teng, Tie-Kuang Dong, W. H. Shen, Z. T. Shen, D. D'Urso, Zu-Cheng Chen, L. G. Wang, Dong Ya Guo, Xiaoyuan Huang, Y. M. Hu, F. de Palma, Hao Ting Dai, C. Perrina, Tianxiao Ma, Donghong Chen, Kai-Kai Duan, Maksym Deliyergiyev, D. Kyratzis, K. Gong, Chengrui Zhou, Mn Mazziotta, G. Z. Shang, Shuang Xue Han, J. J. Zang, Huaguang Wang, Alemanno F., An Q., Azzarello P., Barbato F.C.T., Bernardini P., Bi X.J., Cai M.S., Catanzani E., Chang J., Chen D.Y., Chen J.L., Chen Z.F., Cui M.Y., Cui T.S., Cui Y.X., Dai H.T., D'amone A., De Benedittis A., De Mitri I., De Palma F., Deliyergiyev M., Di Santo M., Dong T.K., Dong Z.X., Donvito G., Droz D., Duan J.L., Duan K.K., D'urso D., Fan R.R., Fan Y.Z., Fang K., Fang F., Feng C.Q., Feng L., Fusco P., Gao M., Gargano F., Gong K., Gong Y.Z., Guo D.Y., Guo J.H., Guo X.L., Han S.X., Hu Y.M., Huang G.S., Huang X.Y., Huang Y.Y., Ionica M., Jiang W., Kong J., Kotenko A., Kyratzis D., Lei S.J., Li S., Li W.L., Li X., Li X.Q., Liang Y.M., Liu C.M., Liu H., Liu J., Liu S.B., Liu W.Q., Liu Y., Loparco F., Luo C.N., Ma M., Ma P.X., Ma T., Ma X.Y., Marsella G., Mazziotta M.N., Mo D., Niu X.Y., Pan X., Parenti A., Peng W.X., Peng X.Y., Perrina C., Qiao R., Rao J.N., Ruina A., Salinas M.M., Shang G.Z., Shen W.H., Shen Z.Q., Shen Z.T., Silveri L., Song J.X., Stolpovskiy M., Su H., Su M., Sun Z.Y., Surdo A., Teng X.J., Tykhonov A., Wang H., Wang J.Z., Wang L.G., Wang S., Wang X.L., Wang Y., Wang Y.F., Wang Y.Z., Wang Z.M., Wei D.M., Wei J.J., Wei Y.F., Wen S.C., Wu D., Wu J., Wu L.B., Wu S.S., Wu X., Xia Z.Q., Xu H.T., Xu Z.H., Xu Z.L., Xu Z.Z., Xue G.F., Yang H.B., Yang P., Yang Y.Q., Yao H.J., Yu Y.H., Yuan G.W., Yuan Q., Yue C., Zang J.J., Zhang F., Zhang S.X., Zhang W.Z., Zhang Y., Zhang Y.J., Zhang Y.L., Zhang Y.P., Zhang Y.Q., Zhang Z., Zhang Z.Y., Zhao C., Zhao H.Y., Zhao X.F., Zhou C.Y., Zhu Y., Alemanno, F., An, Q., Azzarello, P., Barbato, F. C. T., Bernardini, P., Bi, X. J., Cai, M. S., Catanzani, E., Chang, J., Chen, D. Y., Chen, J. L., Chen, Z. F., Cui, M. Y., Cui, T. S., Cui, Y. X., Dai, H. T., D’Amone, A., De Benedittis, A., De Mitri, I., de Palma, F., Deliyergiyev, M., Di Santo, M., Dong, T. K., Dong, Z. X., Donvito, G., Droz, D., Duan, J. L., Duan, K. K., D’Urso, D., Fan, R. R., Fan, Y. Z., Fang, K., Fang, F., Feng, C. Q., Feng, L., Fusco, P., Gao, M., Gargano, F., Gong, K., Gong, Y. Z., Guo, D. Y., Guo, J. H., Guo, X. L., Han, S. X., Hu, Y. M., Huang, G. S., Huang, X. Y., Huang, Y. Y., Ionica, M., Jiang, W., Kong, J., Kotenko, A., Kyratzis, D., Lei, S. J., Li, S., Li, W. L., Li, X., Li, X. Q., Liang, Y. M., Liu, C. M., Liu, H., Liu, J., Liu, S. B., Liu, W. Q., Liu, Y., Loparco, F., Luo, C. N., Ma, M., Ma, P. X., Ma, T., Ma, X. Y., Marsella, G., Mazziotta, M. N., Mo, D., Niu, X. Y., Pan, X., Parenti, A., Peng, W. X., Peng, X. Y., Perrina, C., Qiao, R., Rao, J. N., Ruina, A., Salinas, M. M., Shang, G. Z., Shen, W. H., Shen, Z. Q., Shen, Z. T., Silveri, L., Song, J. X., Stolpovskiy, M., Su, H., Su, M., Sun, Z. Y., Surdo, A., Teng, X. J., Tykhonov, A., Wang, H., Wang, J. Z., Wang, L. G., Wang, S., Wang, X. L., Wang, Y., Wang, Y. F., Wang, Y. Z., Wang, Z. M., Wei, D. M., Wei, J. J., Wei, Y. F., Wen, S. C., Wu, D., Wu, J., Wu, L. B., Wu, S. S., Wu, X., Xia, Z. Q., Xu, H. T., Xu, Z. H., Xu, Z. L., Xu, Z. Z., Xue, G. F., Yang, H. B., Yang, P., Yang, Y. Q., Yao, H. J., Yu, Y. H., Yuan, G. W., Yuan, Q., Yue, C., Zang, J. J., Zhang, F., Zhang, S. X., Zhang, W. Z., Zhang, Y., Zhang, Y. J., Zhang, Y. L., Zhang, Y. P., Zhang, Y. Q., Zhang, Z., Zhang, Z. Y., Zhao, C., Zhao, H. Y., Zhao, X. F., Zhou, C. Y., and Zhu, Y.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Dark matter, General Physics and Astronomy, chemistry.chemical_element, FOS: Physical sciences, Cosmic ray, Space (mathematics), 01 natural sciences, 7. Clean energy, Cosmic ray, helium, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, Energy spectrum, cosmic rays, dark matter, space, crystals, 010306 general physics, Helium, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), COSMIC cancer database, detector, Settore FIS/01 - Fisica Sperimentale, calibration, chemistry, Particle, Astrophysics - High Energy Astrophysical Phenomena, Nucleon, performance
Abstract

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the DArk Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of $4.3\sigma$. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out., Comment: 11 pages, 13 figures, published in Phys. Rev. Lett. Add one more digit for first three columns in Table S2

Published
2021

31. Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

Author

F, Aharonian, Q, An, Axikegu, L X, Bai, Y X, Bai, Y W, Bao, D, Bastieri, X J, Bi, Y J, Bi, H, Cai, J T, Cai, Z, Cao, J, Chang, J F, Chang, X C, Chang, B M, Chen, J, Chen, L, Chen, M J, Chen, M L, Chen, Q H, Chen, S H, Chen, S Z, Chen, T L, Chen, X L, Chen, Y, Chen, N, Cheng, Y D, Cheng, S W, Cui, X H, Cui, Y D, Cui, B Z, Dai, H L, Dai, Z G, Dai, Danzengluobu, D, Della Volpe, B, D'Ettorre Piazzoli, X J, Dong, J H, Fan, Y Z, Fan, Z X, Fan, J, Fang, K, Fang, C F, Feng, L, Feng, S H, Feng, Y L, Feng, B, Gao, C D, Gao, Q, Gao, W, Gao, M M, Ge, L S, Geng, G H, Gong, Q B, Gou, M H, Gu, J G, Guo, X L, Guo, Y Q, Guo, Y Y, Guo, Y A, Han, H H, He, H N, He, J C, He, S L, He, X B, He, Y, He, M, Heller, Y K, Hor, C, Hou, X, Hou, H B, Hu, S, Hu, S C, Hu, X J, Hu, D H, Huang, Q L, Huang, W H, Huang, X T, Huang, Z C, Huang, F, Ji, X L, Ji, H Y, Jia, K, Jiang, Z J, Jiang, C, Jin, D, Kuleshov, K, Levochkin, B B, Li, C, Li, F, Li, H B, Li, H C, Li, H Y, Li, J, Li, K, Li, W L, Li, X, Li, X R, Li, Y, Li, Y Z, Li, Z, Li, E W, Liang, Y F, Liang, S J, Lin, B, Liu, C, Liu, D, Liu, H, Liu, H D, Liu, J, Liu, J L, Liu, J S, Liu, J Y, Liu, M Y, Liu, R Y, Liu, S M, Liu, W, Liu, Y N, Liu, Z X, Liu, W J, Long, R, Lu, H K, Lv, B Q, Ma, L L, Ma, X H, Ma, J R, Mao, A, Masood, W, Mitthumsiri, T, Montaruli, Y C, Nan, B Y, Pang, P, Pattarakijwanich, Z Y, Pei, M Y, Qi, D, Ruffolo, V, Rulev, A, Sáiz, L, Shao, O, Shchegolev, X D, Sheng, J R, Shi, H C, Song, Yu V, Stenkin, V, Stepanov, Q N, Sun, X N, Sun, Z B, Sun, P H T, Tam, Z B, Tang, W W, Tian, B D, Wang, C, Wang, H, Wang, H G, Wang, J C, Wang, J S, Wang, L P, Wang, L Y, Wang, R N, Wang, W, Wang, X G, Wang, X J, Wang, X Y, Wang, Y D, Wang, Y J, Wang, Y P, Wang, Z, Wang, Z H, Wang, Z X, Wang, D M, Wei, J J, Wei, Y J, Wei, T, Wen, C Y, Wu, H R, Wu, S, Wu, W X, Wu, X F, Wu, S Q, Xi, J, Xia, J J, Xia, G M, Xiang, G, Xiao, H B, Xiao, G G, Xin, Y L, Xin, Y, Xing, D L, Xu, R X, Xu, L, Xue, D H, Yan, C W, Yang, F F, Yang, J Y, Yang, L L, Yang, M J, Yang, R Z, Yang, S B, Yang, Y H, Yao, Z G, Yao, Y M, Ye, L Q, Yin, N, Yin, X H, You, Z Y, You, Y H, Yu, Q, Yuan, H D, Zeng, T X, Zeng, W, Zeng, Z K, Zeng, M, Zha, X X, Zhai, B B, Zhang, H M, Zhang, H Y, Zhang, J L, Zhang, J W, Zhang, L, Zhang, L X, Zhang, P F, Zhang, P P, Zhang, R, Zhang, S R, Zhang, S S, Zhang, X, Zhang, X P, Zhang, Y, Zhang, Y F, Zhang, Y L, Zhang, B, Zhao, J, Zhao, L, Zhao, L Z, Zhao, S P, Zhao, F, Zheng, Y, Zheng, B, Zhou, H, Zhou, J N, Zhou, P, Zhou, R, Zhou, X X, Zhou, C G, Zhu, F R, Zhu, H, Zhu, K J, Zhu, X, Zuo, and X Y, Huang

Abstract

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E25 TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160 TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

Published
2021

32. Discovery of the Ultra-high energy gamma-ray source LHAASO J2108+5157

Author

Zhen Cao, F. Aharonian, Q. An, null Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Zhe Cao, J. Chang, J. F. Chang, B. M. Chen, E. S. Chen, J. Chen, Liang Chen, Long Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. D’Ettorre Piazzoli, B. Z. Dai, H. L. Dai, Z. G. Dai, Dan-Zeng Dan-Zeng-Luo-Bu, D. della Volpe, X. J. Dong, K. K. Duan, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, L. Q. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, F. L. Guo, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, X. Y. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, T. Ke, D. Kuleshov, K. Levochkin, B. B. Li, Cheng Li, Cong Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. R. Li, Xin Li, Y. Li, Y. Z. Li, Zhe Li, Zhuo Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, Z. Min, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, Y. Q. Qi, B. Q. Qiao, J. J. Qin, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. Y. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Y. Su, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. H. Wang, Z. X. Wang, Zhen Wang, Zheng Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, D. X. Xiao, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, J. Z. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. X. Zhang, Li Zhang, Lu Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. F. Zhang, Y. L. Zhang, Yi Zhang, Yong Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, and X. Zuo

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Molecular cloud, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Gamma ray, Flux, Sigma, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Gamma-ray astronomy, Space and Planetary Science, Energy spectrum, Ultrahigh energy, Astrophysics - High Energy Astrophysical Phenomena
Abstract

We report the discovery of a UHE gamma-ray source, LHAASO J2108+5157, by analyzing the LHAASO-KM2A data of 308.33 live days. Significant excess of gamma-ray induced showers is observed in both energy bands of 25-100 TeV and $\gt$100 TeV with 9.5 sigma and 8.5 sigma, respectively. This source is not significantly favored as an extensive source with the angular extension smaller than the point-spread function of KM2A. The measured energy spectrum from 20 to 200 TeV can be approximately described by a power-law function with an index of -2.83$\pm$ 0.18stat. A harder spectrum is demanded at lower energies considering the flux upper limit set by Fermi-LAT observations. The position of the gamma-ray emission is correlated with a giant molecular cloud, which favors a hadronic origin. No obvious counterparts have been found, deeper multiwavelength observations will help to shed new light on this intriguing UHE source., Comment: 12 pages, 7 figures, accepted by ApJL

Published
2021
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33. CONVERGENT SYNTHESIS AND EVALUATION OF 18F-LABELED AZULENIC COX2 PROBES FOR CANCER IMAGING

Author

Donald D. Nolting, Michael eNickels, Mohammed N. Tantawy, James Y. H. Yu, Jingping eXie, Todd E. Peterson, Brenda A. Crews, Larry eMarnett, John C. Gore, and Wellington ePham

Subjects
Molecular Imaging, Cancer, PET, COX2, Azulene, xenograft tumor, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
Abstract

The overall objectives of this research are to (i) develop azulene-based PET probes and (ii) image COX2 as a potential biomarker of breast cancer. Several lines of research have demonstrated that COX2 is overexpressed in breast cancer and that its presence correlates with poor prognoses. While other studies have reported that COX2 inhibition can be modulated and used beneficially as a chemopreventive strategy in cancer, no viable mechanism for achieving that approach has yet been developed. This shortfall could be circumvented through in vivo imaging of COX2 activity, particularly using sensitive imaging techniques such as PET. Toward that goal, our laboratory focuses on the development of novel 18F-labled COX2 probes. We began the synthesis of the probes by transforming tropolone into a lactone, which was subjected to an [8+2] cycloaddition reaction to yield 2-methylazulene as the core ring of the probe. After exploring numerous synthetic routes, the final target molecule and precursor PET compounds were prepared successfully using convergent synthesis. Conventional 18F labeling methods caused precursor decomposition, which prompted us to hypothesize that the acidic protons of the methylene moiety between the azulene and thiazole rings were readily abstracted by a strong base such as potassium carbonate. Ultimately, this caused the precursors to disintegrate. This observation was supported after successfully using an 18F labeling strategy that employed a much milder phosphate buffer. The 18F-labeled COX2 probe was tested in a breast cancer xenograft mouse model. The data obtained via successive whole-body PET/CT scans indicated probe accumulation and retention in the tumor. Overall, the probe was stable in vivo and no defluorination was observed. A biodistribution study and Western blot analysis corroborate with the imaging data. In conclusion, this novel COX2 PET probe was shown to be a promising agent for cancer imaging and deserves further investigation.

Published
2013
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34. ψ(2S) Hadronic Decays to Vector-Tensor Final States

Author

Dehong Zhang, W. G. Yan, I. Blum, F. Sun, A. J. Lankford, Qiyang Zhang, H. Z. Shi, Y. H. Yu, Chun-Hua Jiang, Q. M. Zhu, J. Z. Bai, X. F. Song, Lei Zhang, Joseph Izen, G. Rong, Y. Z. Huang, P. Wang, L. Z. Wang, W. G. Li, J. Panetta, Y. C. Zhu, Kai Yi, M. Z. Wang, L. P. Zhou, F. C. Porter, Z. G. Zhao, M. H. Kelsey, D. M. Xi, J. G. Lu, J. Yan, Jiming Yang, F. Wang, C. H. Luo, P. L. Wang, Z. Z. Du, H. S. Sun, L. J. Pan, Z. P. Mao, Meng Wang, Y. X. Ye, H. M. Liu, S. T. Xue, S. M. Wang, X. N. Li, X. C. Lou, H. Shen, P. Gratton, J. H. Liu, Q. H. Hu, J. Y. Zhang, T. Hu, F. Lu, Y. H. Xie, Y. G. Xie, Y. K. Que, J. Chen, G. Y. Hu, X. M. Xia, H. M. Hu, Michael Schernau, T. J. Wang, H. L. Ding, Z. W. Chai, W. Yang, J. Nie, J. G. Bian, D. H. Zhang, C. S. Yu, F. A. Harris, H. Y. Sheng, Z. Q. Yu, Y. Y. Zhang, C. Z. Yuan, X. Q. Hu, E. C. Ma, H. L. Zhang, Y. Y. Shao, S. D. Gu, S.L. Olsen, Cunfeng Wei, H. B. Li, C. S. Gao, D. G. Hitlin, J. W. Zhang, J. P. Liu, H. S. Mao, G. P. Chen, W. D. Li, S. Feng, Y. F. Gu, C. X. Yu, Shun-Qi Zhang, M. He, D. L. Shen, N. D. Qi, Y. B. Chen, X. C. Meng, W. J. Xiong, P. F. Lang, Jinxing Zheng, J. D. Huang, J. F. Qiu, Y. Jin, R. B. Li, J. Standifird, C. D. Qian, C. C. Zhang, M. G. Zhao, L. Y. Dong, G. P. Zhou, D. Kong, Cheng-Kui Li, W. X. Gu, Y. N. Guo, B. S. Cheng, W. H. Toki, Y. L. Han, W. R. Zhao, B. W. Shen, L. C. Lu, G. F. Xu, B. Lowery, D. Paluselli, J. He, S. Q. Gao, Z. J. Ke, W. Dunwoodie, X. R. Qi, J. L. Zhang, Y. Zhang, J. C. Li, P. P. Xie, J. C. Chen, R. Malchow, D. Li, C. M. Yang, J. W. Zhao, Y. Yuan, Y. S. Zhu, J. H. Gu, L. S. Zheng, P. Q. Li, X. Y. Shen, Z. P. Zheng, J. Oyang, X. Y. Zhang, R. G. Liu, L. S. Wang, M. H. Ye, G. L. Tong, B. A. Zhuang, M. L. Gao, S. Q. Tang, Wei Li, L. Y. Ding, Y. H. Qu, B. K. Kim, Y. F. Lai, H. F. Chen, S. W. Han, A. M. Ma, H. S. Zhou, H. W. Zhao, C. Y. Yang, Jun-Bing Ma, Xingzhu Cui, Z. T. Yu, D. X. Zhao, B. Y. Zhang, Y. Y. Wang, S. W. Ye, M. Weaver, J. L. Hu, Y. G. Wu, J. J. He, Y. Q. Chen, X. H. Li, J. Y. Lu, C. C. Xu, Y. B. Liu, and Xuan Yang

Subjects
Physics, Particle physics, Hadron, Tensor
Published
2020
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36. Vertical Silicon Nanowire Platform for Low Power Electronics and Clean Energy Applications

Author

D.-L. Kwong, X. Li, Y. Sun, G. Ramanathan, Z. X. Chen, S. M. Wong, Y. Li, N. S. Shen, K. Buddharaju, Y. H. Yu, S. J. Lee, N. Singh, and G. Q. Lo

Subjects
Technology (General), T1-995
Abstract

This paper reviews the progress of the vertical top-down nanowire technology platform developed to explore novel device architectures and integration schemes for green electronics and clean energy applications. Under electronics domain, besides having ultimate scaling potential, the vertical wire offers (1) CMOS circuits with much smaller foot print as compared to planar transistor at the same technology node, (2) a natural platform for tunneling FETs, and (3) a route to fabricate stacked nonvolatile memory cells. Under clean energy harvesting area, vertical wires could provide (1) cost reduction in photovoltaic energy conversion through enhanced light trapping and (2) a fully CMOS compatible thermoelectric engine converting waste-heat into electricity. In addition to progress review, we discuss the challenges and future prospects with vertical nanowires platform.

Published
2012
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37. Absolute calibration of LHAASO WFCTA camera based on LED

Author

W. J. Long, Rong Xu, Cong Li, J. J. Xia, Houdun Zeng, Axikegu, Yongchun Wang, H. H. He, Xufang Li, X. X. Zhai, Y. D. Cui, L. Feng, H. B. Li, F. R. Zhu, Qie Sun, Yi Chen, F. Y. Li, C. F. Feng, D. H. Huang, Bin Zhou, J. Y. Shi, V. I. Stepanov, H. Zhu, Jun-Jie Wei, L. Z. Zhao, F. Ji, M. Zha, Jia Zhang, Y. H. Yao, Yi Zhang, B. Q. Qiao, Rui Zhang, Linbin Yang, Zhengguo Cao, M. L. Chen, Jianeng Zhou, Jian Wang, Chiming Jin, Zhe Cao, M. M. Ge, X. Zuo, Xuliang Chen, D.A. Kuleshov, Hong-Guang Wang, Y. He, Xiang-Yu Wang, E. S. Chen, Y. A. Han, N. Cheng, J. Fang, S. Hu, J. Y. Liu, G. M. Xiang, H. C. Song, S. P. Zhao, Zebo Tang, H. B. Xiao, W. Liu, L. X. Bai, Binyu Zhao, Yun-Feng Liang, Tao Zeng, Jixia Li, W. Zeng, Bin Ma, Donglian Xu, Z. Min, Xuelong Wang, Xiaofei Zhang, X. L. Guo, X. J. Dong, Hefan Li, S. H. Feng, Q. H. Chen, G. G. Xin, Warit Mitthumsiri, Kai-Kai Duan, Ying Zhang, P. F. Zhang, Z. X. Wang, H.Y. Gan, T. Wen, S. W. Cui, K. Levochkin, Hao Zhou, W. Wang, P. Pattarakijwanich, Kun Fang, D. M. Wei, H. Cai, S. Wu, Sina Chen, X. D. Sheng, Minghao Qi, C. X. Liu, Y. L. Feng, D. Bastieri, Q. An, B. Y. Pang, B. Liu, B. D. Wang, T. Ke, S. B. Yang, Bai Yibing, Lidan Gao, Y. W. Bao, Y. C. Nan, S. Z. Chen, Zhe Li, Shi-Qi Hu, X. H. You, H. B. Hu, H. Liu, X. T. Huang, J. C. He, Bingshui Gao, R. Zhou, L. Y. Wang, Z. H. Wang, Li Zhang, Z. G. Dai, M. J. Yang, Fan Yang, A. Masood, David Ruffolo, C. W. Yang, Q. Gao, Jun Liu, Z. K. Zeng, C. D. Gao, Lei Zhao, Z. C. Huang, B. B. Li, G. H. Gong, Lang Shao, M. J. Chen, Y. J. Wang, H. M. Zhang, D. della Volpe, He Zhang, Jianguo Qin, Y. J. Bi, Jun-Hui Fan, H. D. Liu, W. H. Huang, Y. D. Cheng, Z. B. Sun, Bo Zhang, Duo Yan, Z. X. Liu, Ruizhi Yang, X. N. Sun, Li-Sheng Geng, S. L. He, W. L. Li, Y. P. Wang, Y. H. Yu, Z. G. Yao, D. X. Xiao, J.W. Xia, X. G. Wang, H. L. Dai, Y. Y. Guo, Danzengluobu, Y. Q. Qi, H. Wang, W. Gao, Yi Liu, J. B. Zhao, Y. K. Hor, J. Chen, Zheng Wang, Q. B. Gou, L. P. Wang, Qizhi Huang, T. L. Chen, X. F. Wu, X. L. Ji, R. Lu, Cheng Guang Zhu, Zhuo Li, T. Montaruli, S. Q. Xi, Zhen Wang, Y.T. Fu, G. C. Xiao, Y. Z. Fan, X. H. Cui, Z. Y. Pei, B. D'Ettorre Piazzoli, W. X. Wu, H. Y. Jia, Y. Wang, B. Z. Dai, Alejandro Sáiz, Youping Li, J. T. Cai, R. Liu, Long Chen, Y. J. Wei, Fengqin Guo, J. F. Chang, V. Rulev, L. Xue, Liang Chen, Y. L. Xin, Yugang Zhang, Xinbo He, K. Jiang, X. J. Bi, X. J. Hu, Y. Zheng, L. Q. Yin, X. Y. Huang, J. W. Zhang, P. P. Zhang, Wenwu Tian, Pak-Hin Thomas Tam, H. C. Li, Z. X. Fan, Z. Y. You, J. Y. Yang, Ping Zhou, Junjie Mao, Y. Z. Li, F. Zheng, Y. Q. Guo, H. R. Wu, B. M. Chen, X. X. Zhou, Q. Yuan, Felix Aharonian, H. N. He, M. Heller, K. Li, L. L. Ma, Yu. V. Stenkin, Z. J. Jiang, J. Liu, Yong Zhang, R. N. Wang, C. Hou, Shuibin Lin, S. M. Liu, Lu Zhang, J. S. Wang, Cunguo Wang, E. W. Liang, N. Yin, K. J. Zhu, Minghui Liu, Shengxue Zhang, Cheng Li, Dong Liu, Jinyao Liu, C. Y. Wu, Y. M. Ye, Yunchao Liu, Y. M. Xing, H. K. Lv, X. H. Ma, Xiang Zhang, Y. Su, J. G. Guo, S. R. Zhang, M. H. Gu, L. X. Zhang, Jiawei Yan, Xin Li, and Oleg Shchegolev

Subjects
Physics, Nuclear and High Energy Physics, Photon, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Cosmic ray, Metrology, law.invention, Telescope, Air shower, Silicon photomultiplier, Optics, law, Calibration, business, Instrumentation, Cherenkov radiation
Abstract

The main scientific goal of the LHAASO WFCTA experiment is to measure the cosmic ray energy spectra and composition from 10 TeV to 1 EeV. Cherenkov photons in the extensive air shower measured by the SiPM camera of Cherenkov telescopes can be used to reconstruct the cosmic ray energy. The absolute calibration of the camera is a crucial step to achieve the accurate measurement of the cosmic ray energy spectrum. A multi-wavelength cylindrical illuminator based on LEDs is developed and mounted inside the telescope to calibrate and monitor the camera, and the illuminator’s stability is better than 0.5% under the temperature variation from -26 to 26 ° C. A portable probe with a single photoelectron resolution of 21.6% is developed. After calibration by National Institute of Metrology, China (NIM), the probe is taken to the LHAASO site to measure the absolute photon density of the cylindrical illuminator inside the telescope. Based on the illuminator with known photon density, the photon conversion factor of the camera can be calibrated, and the overall calibration uncertainty is less than 2.6%.

Published
2022
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39. Computational modelling and experimental tank testing of the multi float WaveSub under regular wave forcing

Author

Martin Hann, Y-H Yu, Ian Masters, Kelly Ruehl, Graham Foster, Emilio Faraggiana, Deborah Greaves, Gareth Ian Stockman, Andrew Hillis, Jens Roesner, Craig Whitlam, and John Chapman

Subjects
Drag coefficient, Renewable energy, Physical model, 060102 archaeology, Renewable Energy, Sustainability and the Environment, Computer science, 020209 energy, Damping, Tank testing, Wave energy, Wave potential theory, Flow (psychology), 06 humanities and the arts, 02 engineering and technology, Mechanics, Displacement (vector), Power (physics), Inviscid flow, Drag, 0202 electrical engineering, electronic engineering, information engineering, 0601 history and archaeology, Time domain, SDG 7 - Affordable and Clean Energy
Abstract

A submerged wave device generates energy from the relative motion of floating bodies. In WaveSub, three floats are joined to a reactor; each connected to a spring and generator. Electricity generated damps the orbital movements of the floats. The forces are non-linear and each float interacts with the others. Tuning to the wave climate is achieved by changing the line lengths, so there is a need to understand the performance trade-offs for a large number of configurations. This requires an efficient, large displacement, multidirectional, multi-body numerical scheme. Results from a 1/25 scale wave basin experiment are described. Here, we show that a time domain linear potential flow formulation (Nemoh, WEC-Sim) can match the tank testing provided that suitably tuned drag coefficients are employed. Inviscid linear potential models can match some wave device experiments; however, additional viscous terms generally provide better accuracy. Scale experiments are also prone to mechanical friction, and we estimate friction terms to improve the correlation further. The resulting error in mean power between numerical and physical models is approximately 10%. Predicted device movement shows a good match. Overall, drag terms in time domain wave energy modelling will improve simulation accuracy in wave renewable energy device design.

Published
2020
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40. Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

Author

Chi Wang, Y. Z. Gong, Yujuan Liu, Kai-Kai Duan, Yaohui Zhang, L. G. Wang, Dong Ya Guo, Cihang Luo, X. Y. Peng, Jie Liu, Guangshun Huang, Zhi-Yu Sun, S. Wang, R. R. Fan, Maria Ionica, Jie Kong, Peng-Xiong Ma, Zhi Hui Xu, Xiaoyuan Huang, Yu-Sa Wang, N. H. Liao, L. Feng, Michael Ma, H. Liu, X. Y. Ma, Z. X. Dong, Dingsong Wu, Jun-jun Guo, Niu Xiaoyang, A. D'Amone, K. Gong, S. C. Wen, I. De Mitri, P. Azzarello, Min Gao, Chengrui Zhou, Shengxia Zhang, Shumei Wu, Mn Mazziotta, G. Z. Shang, K. Xi, Xian-Min Jin, F. Loparco, Xin-Fu Zhao, Z. Z. Xu, Y. Y. Huang, Shuang Xue Han, X. L. Wang, Zhongjie Yang, Y. H. Yu, G. Marsella, Zhao-Min Wang, Jinglai Duan, Andrii Tykhonov, S. B. Liu, Y. Zhang, Meng Su, Q. An, Y. F. Dong, C. Q. Feng, Xiulian Pan, Ju-Xian Song, Peidong Yang, W. Li, Y. M. Hu, S.X. Li, S. Y. Ma, H. T. Xu, Jindong Zhang, Z. Q. Xia, Yali Zhou, Jialong Chen, J. Z. Wang, X. X. Li, H. Su, M. S. Cai, Jian Wu, X. J. Bi, Haiqiong Wang, Yifan Yang, Tianxiao Ma, F. J. Gan, Donghong Chen, J. J. Zang, Hao Ting Dai, Huaguang Wang, Zhoubin Zhang, P. Bernardini, Z.-Q. Shen, F. Gargano, H. S. Chen, Manyu Ding, Y. F. Liang, R. Qiao, D. Droz, Chuan Yue, W. X. Peng, Y. F. Wei, Shi-Jun Lei, Q. Yuan, Y. J. Zhang, P. Fusco, Yun-Zhi Zhang, A. Surdo, YM Liang, Jiang Chang, J. J. Wei, Lihui Wu, D. Mo, Y. Li, Giacinto Donvito, A. De Benedittis, Wangli Chen, Yang Haibo, Quan Wang, R. Asfandiyarov, M. Di Santo, J. Y. Zhang, Xi Zhu, J. N. Rao, D. M. Wei, Zongye Zhang, Hong Yun Zhao, Yu-Xuan Zhu, D. D'Urso, Hu-Rong Yao, S. Vitillo, Yen-Po Wang, Yugang Zhang, M. Y. Cui, M. M. Salinas, Fang Fang, Wei Liu, T. S. Cui, Huan Zhao, Z. Xu, X. J. Teng, Tie-Kuang Dong, W. H. Shen, Z. T. Shen, Shanta M. Zimmer, Xian Qiang Li, Xin Wu, C. Liu, Y. F. Wang, V. Gallo, W. Zhang, Wei Jiang, Yuqing Fan, Fengtao Zhang, G. F. Xue, Pengchao Zhang, Xiangpeng Guo, Xixian Wang, An Q., Asfandiyarov R., Azzarello P., Bernardini P., Bi X. J., Cai M. S., Chang J., Chen D. Y., Chen H. F., Chen J. L., Chen W., Cui M. Y., Cui T. S., Dai H. T., D'Amone A., De Benedittis A., De Mitri I., Di Santo M., Ding M., Dong T. K., Dong Y. F., Dong Z. X., Donvito G., Droz D., Duan J. L., Duan K. K., D'Urso D., Fan R. R., Fan Y. Z., Fang F., Feng C. Q., Feng L., Fusco P., Gallo V., Gan F. J., Gao M., Gargano F., Gong K., Gong Y. Z., Guo D. Y., Guo J. H., Guo X. L., Han S. X., Hu Y. M., Huang G. S., Huang X. Y., Huang Y. Y., Ionica M., Jiang W., Jin X., Kong J., Lei S. J., Li S., Li W. L., Li X., Li X. Q., Li Y., Liang Y. F., Liang Y. M., Liao N. H., Liu C. M., Liu H., Liu J., Liu S. B., Liu W. Q., Liu Y., Loparco F., Luo C. N., Ma M., Ma P. X., Ma S. Y., Ma T., Ma X. Y., Marsella G., Mazziotta M. N., Mo D., Niu X. Y., Pan X., Peng W. X., Peng X. Y., Qiao R., Rao J. N., Salinas M. M., Shang G. Z., Shen W. H., Shen Z. Q., Shen Z. T., Song J. X., Su H., Su M., Sun Z. Y., Surdo A., Teng X. J., Tykhonov A., Vitillo S., Wang C., Wang H., Wang H. Y., Wang J. Z., Wang L. G., Wang Q., Wang S., Wang X. H., Wang X. L., Wang Y. F., Wang Y. P., Wang Y. Z., Wang Z. M., Wei D. M., Wei J. J., Wei Y. F., Wen S. C., Wu D., Wu J., Wu L. B., Wu S. S., Wu X., Xi K., Xia Z. Q., Xu H. T., Xu Z. H., Xu Z. L., Xu Z. Z., Xue G. F., Yang H. B., Yang P., Yang Y. Q., Yang Z. L., Yao H. J., Yu Y. H., Yuan Q., Yue C., Zang J. J., Zhang F., Zhang J. Y., Zhang J. Z., Zhang P. F., Zhang S. X., Zhang W. Z., Zhang Y., Zhang Y. J., Zhang Y. L., Zhang Y. P., Zhang Y. Q., Zhang Z., Zhang Z. Y., Zhao H., Zhao H. Y., Zhao X. F., Zhou C. Y., Zhou Y., Zhu X., Zhu Y., Zimmer S., An, Q., Asfandiyarov, R., Azzarello, P., Bernardini, P., Bi, X. J., Cai, M. S., Chang, J., Chen, D. Y., Chen, H. F., Chen, J. L., Chen, W., Cui, M. Y., Cui, T. S., Dai, H. T., D'Amone, A., De Benedittis, A., De Mitri, I., Di Santo, M., Ding, M., Dong, T. K., Dong, Y. F., Dong, Z. X., Donvito, G., Droz, D., Duan, J. L., Duan, K. K., D'Urso, D., Fan, R. R., Fan, Y. Z., Fang, F., Feng, C. Q., Feng, L., Fusco, P., Gallo, V., Gan, F. J., Gao, M., Gargano, F., Gong, K., Gong, Y. Z., Guo, D. Y., Guo, J. H., Guo, X. L., Han, S. X., Hu, Y. M., Huang, G. S., Huang, X. Y., Huang, Y. Y., Ionica, M., Jiang, W., Jin, X., Kong, J., Lei, S. J., Li, S., Li, W. L., Li, X., Li, X. Q., Li, Y., Liang, Y. F., Liang, Y. M., Liao, N. H., Liu, C. M., Liu, H., Liu, J., Liu, S. B., Liu, W. Q., Liu, Y., Loparco, F., Luo, C. N., Ma, M., Ma, P. X., Ma, S. Y., Ma, T., Ma, X. Y., Marsella, G., Mazziotta, M. N., Mo, D., Niu, X. Y., Pan, X., Peng, W. X., Peng, X. Y., Qiao, R., Rao, J. N., Salinas, M. M., Shang, G. Z., Shen, W. H., Shen, Z. Q., Shen, Z. T., Song, J. X., Su, H., Su, M., Sun, Z. Y., Surdo, A., Teng, X. J., Tykhonov, A., Vitillo, S., Wang, C., Wang, H., Wang, H. Y., Wang, J. Z., Wang, L. G., Wang, Q., Wang, S., Wang, X. H., Wang, X. L., Wang, Y. F., Wang, Y. P., Wang, Y. Z., Wang, Z. M., Wei, D. M., Wei, J. J., Wei, Y. F., Wen, S. C., Wu, D., Wu, J., Wu, L. B., Wu, S. S., Wu, X., Xi, K., Xia, Z. Q., Xu, H. T., Xu, Z. H., Xu, Z. L., Xu, Z. Z., Xue, G. F., Yang, H. B., Yang, P., Yang, Y. Q., Yang, Z. L., Yao, H. J., Yu, Y. H., Yuan, Q., Yue, C., Zang, J. J., Zhang, F., Zhang, J. Y., Zhang, J. Z., Zhang, P. F., Zhang, S. X., Zhang, W. Z., Zhang, Y., Zhang, Y. J., Zhang, Y. L., Zhang, Y. P., Zhang, Y. Q., Zhang, Z., Zhang, Z. Y., Zhao, H., Zhao, H. Y., Zhao, X. F., Zhou, C. Y., Zhou, Y., Zhu, X., Zhu, Y., and Zimmer, S.

Subjects
dark matter, cosmic rays, space, Proton, Milky Way, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, FOS: Physical sciences, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Kinetic energy, 01 natural sciences, 0103 physical sciences, 010306 general physics, Nuclear Experiment, Research Articles, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Spectral index, Multidisciplinary, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Settore FIS/01 - Fisica Sperimentale, SciAdv r-articles, Physics::Accelerator Physics, High Energy Physics::Experiment, Astrophysics - High Energy Astrophysical Phenomena, Research Article
Abstract

DAMPE satellite has directly measured the cosmic ray proton spectrum from 40 GeV to 100 TeV and revealed a new feature at about 13.6 TeV., The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 1/2 years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

Published
2019

41. Effect of BDNF-TrKB pathway on apoptosis of retinal ganglion cells in glaucomatous animal model

Author

Y, Liang, Y-H, Yu, H-J, Yu, and L-S, Ma

Subjects
Male, Rats, Sprague-Dawley, Retinal Ganglion Cells, Disease Models, Animal, Brain-Derived Neurotrophic Factor, Animals, Receptor, trkB, Apoptosis, Ocular Hypertension, Rats
Abstract

The aim of this paper is to investigate the effect of BDNF-TrKB pathway on AOH by accessing its regulatory role in retinal ganglion cell apoptosis.Acute ocular hypertension (AOH) model in rats was established by anterior chamber perfusion to increase intraocular tension. Rats were randomly divided into AOH group, control group and k252a group, with ten rats in each group. Rats were sacrificed 72 h after animal procedures and eyeballs were harvested. HE staining was used to observe retinal structural changes at different time points. Immunohistochemical staining was used to observe the BDNF-positive cells in retinal tissues. TUNEL staining was conducted to measure apoptosis of retinal ganglion cells. Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and Western blot were performed to detect mRNA and protein levels of BDNF, TrKB, PI3K and ERK1 in retinal tissues, respectively.HE and TUNEL staining showed significant pathological changes and abundant apoptotic cells in rat retina of AOH group and k252a group compared with those of the control group (p0.05). The number of survived retinal ganglion cells in the AOH group was lower than that of the control group (p0.05). K252a group had the lowest number of survived retinal ganglion cells. Immunohistochemical results showed that BDNF was rarely expressed in rat retinal tissues of the control group, which was remarkably pronounced in the AOH group and k252a group. The number of BDNF-positive cells in the k252a group was higher than that in the AOH group (p0.05). RT-PCR and Western blot indicated that mRNA and protein levels of relative genes in BDNF-TrKB and PI3K/ERK1 pathways were upregulated in AOH group (p0.05), but were significantly downregulated in k252a group (p0.05).BNDF-TrKB pathway exerts a protective effect on retina against acute ocular hypertension by reducing retinal cell apoptosis.

Published
2019

43. Geometrical reconstruction of fluorescence events observed by the LHAASO experiment *

Author

F. Aharonian, Q. An, null Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, J. Chang, J. F. Chang, X. C. Chang, B. M. Chen, J. Chen, L. Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, null Danzengluobu, D. della Volpe, B. D'Ettorre Piazzoli, X. J. Dong, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, X. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, D. Kuleshov, K. Levochkin, B. B. Li, C. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. Li, X. R. Li, Y. Li, Y. Z. Li, Z. Li, E. W. Liang, Y. F. Liang, S.J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. R. Shi, H. C. Song, Yu.V. Stenkin, V. Stepanov, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. Wang, Z. H. Wang, Z. X. Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. Zhang, L. X. Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. Zhang, Y. F. Zhang, Y. L. Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, and X. Zuo

Subjects
Physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Detector, Resolution (electron density), Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Cosmic ray, 01 natural sciences, Fluorescence, law.invention, Telescope, Optics, law, 0103 physical sciences, Trajectory, Range (statistics), 010306 general physics, business, Instrumentation, Cherenkov radiation
Abstract

The LHAASO-WFCTA experiment, which aims to observe cosmic rays in the sub-EeV range using the fluorescence technique, uses a new generation of high-performance telescopes. To ensure that the experiment has excellent detection capability associated with the measurement of the energy spectrum, the primary composition of cosmic rays, and so on, an accurate geometrical reconstruction of air-shower events is fundamental. This paper describes the development and testing of geometrical reconstruction for stereo viewed events using the WFCTA (Wide Field of view Cherenkov/Fluorescence Telescope Array) detectors. Two approaches, which take full advantage of the WFCTA detectors, are investigated. One is the stereo-angular method, which uses the pointing of triggered SiPMs in the shower trajectory, and the other is the stereo-timing method, which uses the triggering time of the fired SiPMs. The results show that both methods have good geometrical resolution; the resolution of the stereo-timing method is slightly better than the stereo-angular method because the resolution of the latter is slightly limited by the shower track length.

Published
2021
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44. 23rd Annual Meeting of Chinese Society of Anesthesiology

Author

Wuhua Ma, Y.-H. Yu, W. J. Wang, P. Fort, Muhan Zhang, G. L. Wang, W. Zhong, J. X. Liu, W. B. Sun, Q. Y. Cen, Y. H. Li, H-L. Dong, Y. Tong, M. J. Liu, T. Yu, F. X. Yan, W-G. Hou, Y. X. Bian, Quan Wang, Y. Pan, X. C. Zhao, Y. Yonghao, Y. Liu, A-Q. Yin, S. Y. Wang, B. Wang, D. Wang, Q. X. Cai, K.-L. Xie, X. Ding, Y-X. Wu, W. Guolin, S-Y. Jin, Y-L. Ma, X. H. Huang, W. J. Yang, L. Zhang, B. Liu, W. D. Yao, W. Yang, X. Jiang, R. Shu, N. Li, S. J. Xu, J. Xiaoju, H. T. Zhang, C. Y. Wang, S. Q. Jin, Yonghao Yu, Y. Weidong, C. Yang, Lei Zhang, Y. L. Wang, K. X. Liu, D. Q. Liu, Huafeng Wei, L. Xiong, Z. B. Shen, J. Ding, D. Beibei, Q. W. Liao, Z. X. Chen, X. B. Ding, H. Guo, L. Shen, Q. P. Luo, Z. Chen, Y. G. Huang, S-J. Zhang, Q. Ming, L. Tao, H. Wu, Ye Zhang, S-F. He, Z. Zhishen, C. N. Wu, J. Q. Wei, Hui Dong, Q. Li, Shufang He, Z. Y. Han, E. W. Jensen, Haiyun Wang, Jian-Tong Shen, J. Cheng, Q. Y. Zhang, Y. Qiu, R. Li, G. Wang, C. P. Gu, Y. S. Li, S. Mei, S. Ge, Y. Z. Gong, Shi-Hong Wen, T. Zhao, X. J. Jin, Yuanhai Li, X. Y. Ma, and Q. W. Liu

Subjects
0301 basic medicine, Gerontology, medicine.medical_specialty, business.industry, Alternative medicine, Library science, Chinese society, 03 medical and health sciences, 030104 developmental biology, 0302 clinical medicine, Anesthesiology and Pain Medicine, Anesthesiology, medicine, China, business, 030217 neurology & neurosurgery
Published
2016
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45. Observation of the Crab Nebula with LHAASO-KM2A − a performance study *

Author

F. Aharonian, Q. An, 克古 Axikegu, L. X. Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, X. J. Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, J. Chang, J. F. Chang, X. C. Chang, B. M. Chen, J. Chen, L. Chen, M. J. Chen, M. L. Chen, Q. H. Chen, S. H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Y. Chen, N. Cheng, Y. D. Cheng, S. W. Cui, X. H. Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Z. G. Dai, 罗布 Danzengluobu, D. della Volpe, B. D'Ettorre Piazzoli, X. J. Dong, J. H. Fan, Y. Z. Fan, Z. X. Fan, J. Fang, K. Fang, C. F. Feng, L. Feng, S. H. Feng, Y. L. Feng, B. Gao, C. D. Gao, Q. Gao, W. Gao, M. M. Ge, L. S. Geng, G. H. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, X. L. Guo, Y. Q. Guo, Y. Y. Guo, Y. A. Han, H. H. He, H. N. He, J. C. He, S. L. He, X. B. He, Y. He, M. Heller, Y. K. Hor, C. Hou, X. Hou, H. B. Hu, S. Hu, S. C. Hu, X. J. Hu, D. H. Huang, Q. L. Huang, W. H. Huang, X. T. Huang, Z. C. Huang, F. Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, C. Jin, D. Kuleshov, K. Levochkin, B. B. Li, C. Li, F. Li, H. B. Li, H. C. Li, H. Y. Li, J. Li, K. Li, W. L. Li, X. Li, X. R. Li, Y. Li, Y. Z. Li, Z. Li, E. W. Liang, Y. F. Liang, S. J. Lin, B. Liu, C. Liu, D. Liu, H. Liu, H. D. Liu, J. Liu, J. L. Liu, J. S. Liu, J. Y. Liu, M. Y. Liu, R. Y. Liu, S. M. Liu, W. Liu, Y. N. Liu, Z. X. Liu, W. J. Long, R. Lu, H. K. Lv, B. Q. Ma, L. L. Ma, X. H. Ma, J. R. Mao, A. Masood, W. Mitthumsiri, T. Montaruli, Y. C. Nan, B. Y. Pang, P. Pattarakijwanich, Z. Y. Pei, M. Y. Qi, D. Ruffolo, V. Rulev, A. Sáiz, L. Shao, O. Shchegolev, X. D. Sheng, J. R. Shi, H. C. Song, Yu. V. Stenkin, V. Stepanov, Q. N. Sun, X. N. Sun, Z. B. Sun, P. H. T. Tam, Z. B. Tang, W. W. Tian, B. D. Wang, C. Wang, H. Wang, H. G. Wang, J. C. Wang, J. S. Wang, L. P. Wang, L. Y. Wang, R. N. Wang, W. Wang, X. G. Wang, X. J. Wang, X. Y. Wang, Y. D. Wang, Y. J. Wang, Y. P. Wang, Z. Wang, Z. H. Wang, Z. X. Wang, D. M. Wei, J. J. Wei, Y. J. Wei, T. Wen, C. Y. Wu, H. R. Wu, S. Wu, W. X. Wu, X. F. Wu, S. Q. Xi, J. Xia, J. J. Xia, G. M. Xiang, G. Xiao, H. B. Xiao, G. G. Xin, Y. L. Xin, Y. Xing, D. L. Xu, R. X. Xu, L. Xue, D. H. Yan, C. W. Yang, F. F. Yang, J. Y. Yang, L. L. Yang, M. J. Yang, R. Z. Yang, S. B. Yang, Y. H. Yao, Z. G. Yao, Y. M. Ye, L. Q. Yin, N. Yin, X. H. You, Z. Y. You, Y. H. Yu, Q. Yuan, H. D. Zeng, T. X. Zeng, W. Zeng, Z. K. Zeng, M. Zha, X. X. Zhai, B. B. Zhang, H. M. Zhang, H. Y. Zhang, J. L. Zhang, J. W. Zhang, L. Zhang, L. X. Zhang, P. F. Zhang, P. P. Zhang, R. Zhang, S. R. Zhang, S. S. Zhang, X. Zhang, X. P. Zhang, Y. Zhang, Y. F. Zhang, Y. L. Zhang, B. Zhao, J. Zhao, L. Zhao, L. Z. Zhao, S. P. Zhao, F. Zheng, Y. Zheng, B. Zhou, H. Zhou, J. N. Zhou, P. Zhou, R. Zhou, X. X. Zhou, C. G. Zhu, F. R. Zhu, H. Zhu, K. J. Zhu, and X. Zuo

Subjects
Physics, Nuclear and High Energy Physics, High energy, 010308 nuclear & particles physics, Cosmic distance ladder, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Crab Nebula, 0103 physical sciences, Energy spectrum, 010306 general physics, Instrumentation, Energy (signal processing)
Abstract

A sub-array of the Large High Altitude Air Shower Observatory (LHAASO), KM2A is mainly designed to observe a large fraction of the northern sky to hunt for γ-ray sources at energies above 10 TeV. Even though the detector construction is still underway, half of the KM2A array has been operating stably since the end of 2019. In this paper, we present the KM2A data analysis pipeline and the first observation of the Crab Nebula, a standard candle in very high energy γ-ray astronomy. We detect γ-ray signals from the Crab Nebula in both energy ranges of 10 100 TeV and 100 TeV with high significance, by analyzing the KM2A data of 136 live days between December 2019 and May 2020. With the observations, we test the detector performance, including angular resolution, pointing accuracy and cosmic-ray background rejection power. The energy spectrum of the Crab Nebula in the energy range 10-250 TeV fits well with a single power-law function dN/dE = (1.13 0.05 0.08 ) 10 (E/20 TeV) cm s TeV . It is consistent with previous measurements by other experiments. This opens a new window of γ-ray astronomy above 0.1 PeV through which new ultrahigh-energy γ-ray phenomena, such as cosmic PeVatrons, might be discovered.

Published
2021
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46. Endotoxin‐induced cerebral pathophysiology: differences between fetus and newborn

Author

Susan Y. S. Feng, David James Phillips, Victor Y H Yu, Thilini Samarasinghe, Jacob Harvey Hollis, Shripada Rao, and Adrian M. Walker

Subjects
Central Nervous System, Lipopolysaccharides, Male, medicine.medical_specialty, endotoxin, Physiology, injury, medicine.medical_treatment, Immunology, 030204 cardiovascular system & hematology, Maternal, Fetal and Neonatal Physiology, Cardiovascular Physiology, Neurological Conditions, Disorders and Treatments, 03 medical and health sciences, Cerebral circulation, 0302 clinical medicine, newborn, Physiology (medical), Internal medicine, medicine, Animals, Saline, Nitrites, Original Research, Fetus, Nitrates, Sheep, business.industry, Tumor Necrosis Factor-alpha, Macrophages, Brain, Pathophysiology, Vasodilation, fetus, Fetal Diseases, Endocrinology, Cerebral blood flow, Vasoconstriction, Cerebrovascular Circulation, Circulatory system, Encephalitis, Tumor necrosis factor alpha, Female, medicine.symptom, business, Toxins, Pollutants and Chemical Agents, 030217 neurology & neurosurgery
Abstract

As the comparative pathophysiology of perinatal infection in the fetus and newborn is uncertain, this study contrasted the cerebral effects of endotoxemia in conscious fetal sheep and newborn lambs. Responses to intravenous bacterial endotoxin (lipopolysaccharide, LPS) or normal saline were studied on three consecutive days in fetal sheep (LPS 1 μg/kg, n = 5; normal saline n = 5) and newborn lambs (LPS 2 μg/kg, n = 10; normal saline n = 5). Cerebro‐vascular function was assessed by monitoring cerebral blood flow (CBF) and cerebral vascular resistance (CVR) over 12 h each day, and inflammatory responses were assessed by plasma TNF alpha (TNF‐α), nitrate and nitrite concentrations. Brain injury was quantified by counting both resting and active macrophages in the caudate nucleus and periventricular white matter (PVWM). An acute cerebral vasoconstriction (within 1 h of LPS injection) occurred in both the fetus (ΔCVR +53%) and newborn (ΔCVR +63%); subsequently prolonged cerebral vasodilatation occurred in the fetus (ΔCVR −33%) in association with double plasma nitrate/nitrite concentrations, but not in the newborn. Abundant infiltration of activated macrophages was observed in both CN and PVWM at each age, with the extent being 2–3 times greater in the fetus (P

Published
2019

47. Effect of the JAK2/STAT3 signaling pathway on nerve cell apoptosis in rats with white matter injury

Author

X-M, Chen, Y-H, Yu, L, Wang, X-Y, Zhao, and J-R, Li

Subjects
Male, Neurons, STAT3 Transcription Factor, Cell Survival, Apoptosis, Cerebral Infarction, Janus Kinase 2, Tyrphostins, Hippocampus, White Matter, Rats, Disease Models, Animal, Animals, Humans, Phosphorylation, RNA, Small Interfering, Signal Transduction
Abstract

The Janus activated kinase 2 (JAK2)/signal transducer and the activator of transcription 3 (STAT3) pathway are involved in many physiological processes, such as cell survival, inflammation, development, proliferation and differentiation. Increasing evidence has shown that this pathway also has neuron-specific functions in the central nervous system. In this study, the functional significance of the JAK2/STAT3 signaling pathway in nerve cell apoptosis in rats with white matter injury was evaluated.The rat model of white matter injury was established by ligating bilateral common carotid arteries, and the changes of the JAK2 and STAT3 phosphorylation in hippocampal neurons were evaluated using the immunohistochemistry. In addition, the effects of JAK2 inhibitor AG490 and STAT3 small interfering ribonucleic acids (siRNAs) on the expression of phosphorylated-JAK2 (pJAK2), STAT3 messenger RNAs (mRNAs) and pSTAT3 in hippocampal neurons of white matter injury rats were studied. The effects of both on cerebral infarction volume and neuron apoptosis in white matter injury rats were also investigated.The expression of pJAK2 and pSTAT3 were significantly increased after white matter injury in rats (p0.05). JAK2 inhibitor AG490 markedly decreased the phosphorylation of JAK2 and STAT3 in hippocampal neurons in the model group (p0.05). STAT3 siRNAs remarkably reduced the expression levels of STAT3 mRNA and protein in hippocampus neurons in the model group (p0.05), while having no effect on the expression level of pJAK2 protein. AG490 and STAT3 siRNAs notably attenuated the volume of cerebral infarction in the model group, as well as reduced neuron apoptosis after white matter injury.The inhibition of the JAK2/STAT3 signaling pathway contributed to reducing the volume of cerebral infarction and neuron apoptosis in rats with white matter injury.

Published
2019

48. Aclidinium bromide inhibits proliferation of osteosarcoma cells through regulation of PI3K/Akt pathway

Author

Z-Z, Li, Y-L, Wang, Y-H, Yu, Y-L, Xing, and X-F, Ji

Subjects
Osteosarcoma, Cell Movement, Cell Line, Tumor, Humans, Apoptosis, Bone Neoplasms, Drug Screening Assays, Antitumor, Phosphatidylinositol 3-Kinase, Proto-Oncogene Proteins c-akt, Cell Proliferation, Signal Transduction, Tropanes
Abstract

Osteosarcoma is recognized as the most common primary malignant bone tumor, the 5-year disease-free survival rate in patients with metastatic or recurrent disease is below than 30%. Drug resistance and toxic side effects limit the therapeutic efficacy of osteosarcoma. Therefore, it is urgent to develop new drugs for osteosarcoma treatment. Muscarinic 3 (M3) acetylcholine receptor (AChR) has been demonstrated in nonneurocrest-derived malignancies such as colon, prostate, lung, and ovarian carcinomas. Hence, targeted regulation of M3 AChR may be a possible mechanism for treating tumors. Aclidinium bromide has anti-tumoral properties in several tumors, namely gastric cancer and glioma. In this study, we intended to investigate whether aclidinium bromide, a novel M3 AChR antagonist, had effects on osteosarcoma cells proliferation and migration.The viability of U2 OS cells was detected by cell counting kit-8 (CCK-8) assay. The migration and invasion capabilities were measured by transwell invasion and migration assays. The cell apoptosis rate was tested by Annexin V-fluorescein isothiocyanate (FITC)/Propidum iodide (PI) staining and flow cytometry. Key apoptosis-related and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) signaling pathway-associated were assessed by Western blot analysis.Aclidinium bromide markedly decreased the OD value of U2 OS cells 48 h and 72 h after treatment. The number of positive crystal violet staining cells significantly decreased after treatment with aclidinium bromide. Treatment with aclidinium bromide significantly increased cell apoptosis rate, accompanied by the expression of anti-apoptotic protein Bcl-2 decreased, the expression of pro-apoptotic protein Active caspase-3 and Bax significantly increased in U2 OS cells treated with aclidinium bromide. Additionally, aclidinium bromide suppressed the PI3K/AKT signaling pathway in U2 OS cells.Therefore, the current study reveals that aclidinium bromide might inhibit osteosarcoma cell growth by regulating the PI3K/AKT signaling pathway, which suggests aclidinium bromide is a potential chemotherapeutic agent for osteosarcoma.

Published
2019

49. The on-orbit calibration of DArk Matter Particle Explorer

Author

Chang Qing Feng, A. D'Amone, X.Q. Ma, K. Gong, D. Mo, R. Asfandiyarov, G. Ambrosi, Y. M. Hu, Peng-Xiong Ma, Xun Feng Zhao, Zhi Hui Xu, Jinglai Duan, Tianxiao Ma, G. Z. Shang, H. T. Xu, C. Liu, X. Y. Ma, M. Y. Cui, S. C. Wen, Chenchen Wang, J. J. Zang, Deng Yi Chen, Xixian Wang, M. M. Salinas, Niu Xiaoyang, Yaping Wang, Shanta M. Zimmer, J. N. Rao, Haiqiong Wang, Da Ming Wei, Z. Y. Sun, Hao Ting Dai, V. Gallo, Q. An, Peidong Yang, Honglong Wang, D. D’Urso, Yuan Zhu Wang, Xiulian Pan, W. Zhang, I. De Mitri, H. Liu, Yang Haibo, Wei Liang Li, D.L. Zhang, H. S. Chen, Min Gao, Li Bo Wu, A. De Benedittis, Wangli Chen, Xi Zhu, Shuyao Li, X.B. Tian, Paolo Bernardini, J.N. Dong, Sha Wu, Y. Q. Zhang, Hu-Rong Yao, Kai-Kai Duan, Y. F. Wei, Jin Chang, Jiangtao Guo, F. J. Gan, S. Y. Ma, Wei Jiang, Z. Q. Xia, Yifan Yang, L. G. Wang, P. Azzarello, Y. J. Zhang, F. Gargano, Zhenyu Zhang, Maria Ionica, Jie Kong, Y. F. Liang, Yali Zhou, Jing Xing Song, M. Di Santo, Xin Wu, Y. F. Wang, R. R. Fan, R. Qiao, M. Caragiulo, Yuqing Fan, N. H. Liao, Jindan Zhang, Qian Wang, Y.L. Xin, Jie Liu, Zhoubin Zhang, Y. H. Yu, Zhao-Qiang Shen, T. S. Cui, Zhao-Min Wang, Yun Long Zhang, Yao Ming Liang, G. F. Xue, Shengxia Zhang, Zhongjie Yang, J. J. Wei, Z. Xu, Dan Jiang, F. Loparco, Laiyu Zhang, S. Vitillo, X. L. Wang, Wei Liu, Y. Zhang, Yongxiang Liu, J.B. Zhang, J. L. Chen, Qing Yuan, Meng Su, Z.Z. Xu, G. Marsella, Andrii Tykhonov, S. Wang, X. J. Teng, Tie-Kuang Dong, M. M. Ma, Zhang Yalan, Shi-Jun Lei, D. Droz, Fengtao Zhang, Huan Zhao, S. B. Liu, M. N. Mazziotta, H. Su, A. Surdo, Jin Zhou Wang, S. Garrappa, W. H. Shen, Yinlian Zhu, Z. T. Shen, Pengchao Zhang, Guang Shun Huang, Fang Fang, X. X. Li, Hong Yun Zhao, M. S. Cai, W. X. Peng, Y. Li, Y. Z. Gong, Z. X. Dong, Chang Yi Zhou, X. Y. Peng, Lingyan Feng, K. Xi, Jindong Zhang, Di Wu, Jian Wu, Chuan Yue, Y. Y. Huang, P. Fusco, Y. F. Dong, Shan-Shan Gao, Manyu Ding, Xian-Min Jin, Ambrosi, G., An, Q., Asfandiyarov, R., Azzarello, P., Bernardini, P., Cai, M. S., Caragiulo, M., Chang, J., Chen, D. Y., Chen, H. F., Chen, J. L., Chen, W., Cui, M. Y., Cui, T. S., Dai, H. T., D'Amone, A., Benedittis, De, Mitri, De, I., Ding, Di Santo, M., Dong, J. N., Dong, T. K., Dong, Y. F., Dong, Z. X., Droz, D., Duan, K. K., Duan, J. L., D'Urso, D., Fan, R. R., Fan, Y. Z., Iemail, Author, Fang, F., Feng, C. Q., Feng, L., Fusco, P., Gallo, V., Gan, F., Gao, M., Gao, S. S., Gargano, F., Garrappa, S., Gong, K., Gong, Y. Z., Guo, J. H., Email Author, Hu, Y. M., Huang, G. S., Huang, Y. Y., Ionica, M., Jiang, D., Jiang, W., Jin, X., Kong, J., Lei, S. J., Li, S., Li, X., Li, W. L., Li, Y., Liang, Y. F., Liang, Y. M., Liao, N. H., Liu, C. M., Liu, H., Liu, J., Liu, S. B., Liu, W. Q., Liu, Y., Loparco, F., Ma, M., Ma, P. X., Ma, S. Y., Ma, T., Ma, X. Q., Ma, X. Y., Marsella, G., Mazziotta, M. N., Mo, D., Niu, X. Y., Pan, X, Peng, X. Y., Peng, W. X., Qiao, R., Rao, J. N., Salinas, M. M., Shang, G. Z., Shen, W. H., Shen, Z. Q., Shen, Z. T., Song, J. X., Su, H., Su, M., Sun, Z. Y., Surdo, A., Teng, X. J., Tian, X. B., Tykhonov, A., Vitillo, S., Wang, C., Wang, H., Wang, H. Y., Wang, J. Z., Wang, L. G., Wang, Q., Wang, S., Wang, X. H., Wang, X. L., Wang, Y. F., Wang, Y. P., Wang, Y. Z., Wang, Z. M., Wen, S. C., Wei, D. M., Wei J. J., A, Wei Y. F., C, Wu D., J, Wu J., A, H, Wu, L. B., c Wu, S. S., k Wu, X., d Xi, K., j Xia, Z. Q., a h, Xin Y. L., A, Xu H. T., K, Xu Z. H., A, H, Xu, Z. L., a Xu, Z. Z., a Xue, G. F., k Yang, H. B., j Yang, P., j Yang, Y. Q., j Yang, Z. L., j Yao, H. J., j Yu, Y. H., j Yuan, Q., a h, Yue C., A, Zang J. J., A, Zhang D. L., C, Zhang F., M, Zhang J. B., C, Zhang J. Y., M, Zhang J. Z., J, Zhang L., A, I, Zhang, P. F., a Zhang, S. X., j Zhang, W. Z., k Zhang, Y., a i, Zhang Y. J., J, Zhang Y. Q., A, Y. L., c Zhang, Y. P., j Zhang, Z., a Zhang, Z. Y., c Zhao, H., m Zhao, H. Y., j Zhao, X. F., k Zhou, C. Y., k Zhou, Y., j Zhu, X., c Zhu, Y., k Zimmer, Ambrosi G., An Q., Asfandiyarov R., Azzarello P., Bernardini P., Cai M. S., Caragiulo M., Chang J., Chen D. Y., Chen H. F., Chen J. L., Chen W., Cui M. Y., Cui T. S., Dai H. T., D'Amone A., De Beneditti, De Mitri, I. Ding, Dong J. N., Dong T. K., Dong Y. F., Dong Z. X., Droz D., Duan K. K., Duan J. L., D'Urso D., Fan R. R., Fan Y. Z., iEmail Author, Fang F., Feng C. Q., Feng L., Fusco P., Gallo V., Gan F., Gao M., Gao S. S., Gargano F., Garrappa S., Gong K., Gong Y. Z., J. H. Email Author, Hu Y. M., Huang G. S., Huang Y. Y., Ionica M., Jiang D., Jiang W., Jin X., Kong J., Lei S. J., Li S., Li X., Li W. L., Li Y., Liang Y. F., Liang Y. M., Liao N. H., Liu C. M., Liu H., Liu J., Liu S. B., Liu W. Q., Liu Y., Loparco F., Ma M., Ma P. X., Ma S. Y., Ma T., Ma X. Q., Ma X. Y., Marsella G., Mazziotta M. N., Mo D., Niu X. Y., Pan X, Peng X. Y., Peng W. X., Qiao R., Rao J. N., Salinas M. M., Shang G. Z., Shen W. H., Shen Z. Q., Shen Z. T., Song J. X., Su H., Su M., Sun Z. Y., Surdo A., Teng X. J., Tian X. B., Tykhonov A., Vitillo S., Wang C., Wang H., Wang H. Y., Wang J. Z., Wang L. G., Wang Q., Wang S., Wang X. H., Wang X. L., Wang Y. F., Wang Y. P., Wang Y. Z., Wang Z. M., Wen S. C., Wei D. M., Wei J. J. a, Wei Y. F. c, Wu D. j, Wu J. a, h Wu, L. B. c Wu, S. S. k Wu, X. d Xi, K. j Xia, Z. Q. a h, Xin Y. L. a, Xu H. T. k, Xu Z. H. a, h Xu, Z. L. a Xu, Z. Z. a Xue, G. F. k Yang, H. B. j Yang, P. j Yang, Y. Q. j Yang, Z. L. j Yao, H. J. j Yu, Y. H. j Yuan, Q. a h, Yue C. a, Zang J. J. a, Zhang D. L. c, Zhang F. m, Zhang J. B. c, Zhang J. Y. m, Zhang J. Z. j, Zhang L. a, i Zhang, P. F. a Zhang, S. X. j Zhang, W. Z. k Zhang, Y. a i, Zhang Y. J. j, Zhang Y. Q. a, Y. L. c Zhang, Y. P. j Zhang, Z. a Zhang, Z. Y. c Zhao, H. m Zhao, H. Y. j Zhao, X. F. k Zhou, C. Y. k Zhou, Y. j Zhu, X. c Zhu, and Y. k Zimmer

Subjects
Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, FOS: Physical sciences, Cosmic ray, Scintillator, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, Neutron detection, Dark Matter, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Calorimeter (particle physics), 010308 nuclear & particles physics, Detector, Settore FIS/01 - Fisica Sperimentale, Gamma ray, Astronomy, Astronomy and Astrophysics, Cosmic Rays, South Atlantic Anomaly, High Energy Physics::Experiment, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

The DArk Matter Particle Explorer (DAMPE), a satellite-based cosmic ray and gamma-ray detector, was launched on December 17, 2015, and began its on-orbit operation on December 24, 2015. In this work we document the on-orbit calibration procedures used by DAMPE and report the calibration results of the Plastic Scintillator strip Detector (PSD), the Silicon-Tungsten tracKer-converter (STK), the BGO imaging calorimeter (BGO), and the Neutron Detector (NUD). The results are obtained using Galactic cosmic rays, bright known GeV gamma-ray sources, and charge injection into the front-end electronics of each sub-detector. The determination of the boundary of the South Atlantic Anomaly (SAA), the measurement of the live time, and the alignments of the detectors are also introduced. The calibration results demonstrate the stability of the detectors in almost two years of the on-orbit operation.

Published
2019

50. Photomultiplier tube performance of the WCDA++ in the LHAASO experiment

Author

Khuram Tariq, Z. K. Zeng, Dong Liu, Hengying Zhang, Xiurong Li, Y. H. Yu, Cheng Liu, and Cunfeng Feng

Subjects
Physics, Nuclear and High Energy Physics, Photomultiplier, 010308 nuclear & particles physics, Dynamic range, Cherenkov detector, business.industry, Voltage divider, Signal Width, High voltage, 01 natural sciences, law.invention, Air shower, Optics, law, 0103 physical sciences, 010306 general physics, business, Instrumentation, Dark current
Abstract

In the Large High Altitude Air Shower Observatory (LHAASO), the main physics objective of the water Cherenkov detector array (WCDA) is to survey the sky for gamma-ray sources in the energy range of 100 GeV to 30 TeV. In order to extend the dynamic range of the WCDA, a 1.5-inch photomultiplier tube (PMT) is placed aside the 8-inch PMT in each cell of the WCDA. All of these 1.5-inch PMTs (900 in total) consist of the WCDA dynamic extended system (WCDA++). These PMTs are required to maintain linearity within four orders of magnitude. The performance of the 1.5-inch PMTs with a specially designed bi-readout voltage divider is tested with a PMT test system. Accordingly, the effects of the working high voltage and signal width on the dynamic range of the PMTs are studied. The test results show that the dynamic range with a 5% non-linearity for a driven signal width of 5.5 ns is more than 200 kPEs (photoelectrons). The dark noise count rate is less than 200 Hz for a 1 mV threshold at a PMT gain of 2 × 1 0 5 . These results confirm that the PMT performance meets the WCDA++ requirements.

Published
2020
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