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1. 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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2. 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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3. 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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4. Quartz Crystal Microbalance Coated with Sol-gel-derived Thin Films as Gas Sensor for NO Detection

Author: S. J. OÃ¢Â€Â™Shea, H. Gong, F. R. Zhu, J. Q. Hu, and J. Zhang
Subjects: Quartz Crystal Microbalance, Indium tin oxide, gas sensor, resonant frequency, Chemical technology, TP1-1185
Abstract: This paper presents the possibilities and properties of Indium tin oxide (ITO)-covered quartz crystal as a NOx toxic gas-sensor. The starting sol-gel solution was prepared by mixing indium chloride dissolved in acetylacetone and tin chloride dissolved in ethanol (0-20% by weight). The ITO thin films were deposited on the gold electrodes of quartz crystal by spin-coating technique and subsequently followed a standard photolithography to pattern the derived films to ensure all sensors with the same sensing areas. All heat treatment processes were controlled below 500Ã‚Â°C in order to avoid the piezoelectric characteristics degradation of quartz crystal (Quartz will lose its piezoelectricity at ~573Ã‚Â°C due to the phase change from ÃŽÂ± to ÃŽÂ²). The electrical and structural properties of ITO thin films were characterized with Hall analysis system, TG/DTA, XRD, XPS, SEM and etc. The gas sensor had featured with ITO thin films of ~100nm as the receptor to sense the toxic gas NO and quartz crystal with frequency of 10MHz as the transducer to transfer the surface reactions (mass loading, etc) into the frequency shift. A homemade setup had been employed to measure the sensor response under the static mode. The experimental results had indicated that the ITO-coated QCM had a good sensitivity for NO gas, ~12Hz/100ppm within 5mins. These results prove that the ITO-covered quartz crystals are usable as a gas sensor and as an analytical device.
Published: 2003
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5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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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13. Prospects for a Multi-TeV Gamma-ray Sky Survey with the LHAASO Water Cherenkov Detector Array

Author: Guoqing Xiao, Bo Gao, Yu-Hua Yao, B. Q. Qiao, E. W. Liang, X. G. Wang, Yong Zhang, X. C. Chang, X. H. Cui, S. Wu, F. Y. Li, M. M. Ge, H. L. Dai, L. X. Bai, Z. G. Yao, Lei Zhao, Chang Jin, L. Chen, J. W. Zhao, H. D. Liu, Duo Yan, BZ Zhao, Z. X. Liu, Y. C. Nan, H. B. Li, H. K. Lv, B. D'Ettorre Piazzoli, W. X. Wu, Xiao-Yang Zhang, Y. D. Cheng, Z. H. Wang, F. R. Zhu, Y. Wang, M. Zha, P. Zhou, Yi Chen, C. X. Liu, Xufang Li, Yinong Liu, Jun-Jie Wei, Y. Y. Guo, R. Y. Liu, X. F. Wu, L. Zhang, X. J. Wang, H. M. Zhang, V. Rulev, Xiao-Hu Zhang, Y. Yu, C. Y. Wu, Zhe Cao, W. H. Huang, Guanghua Gong, Li-Sheng Geng, B. M. Chen, L. Xue, B. Liu, L. L. Yang, D. H. Huang, Y. A. Han, B. B. Zhang, D. M. Wei, Y. D. Cui, S. R. Zhang, Ziyi Wang, Zhengguo Cao, X. L. Ji, R. Lu, Jianrong Zhou, M. J. Yang, Z. Y. Pei, Y. M. Ye, S. P. Chao, H. C. Li, Jun He, Qiang Yuan, G. M. Xiang, Z. J. Jiang, Jiaxing Li, V. Alekseenko, J. F. Chang, Danzengluobu, H. Y. Jia, J. Chen, Zebo Tang, P. Pattarakijwanich, J. S. Liu, H. Y. Zhang, J. R. Mao, Wang Yanfang, H. Wang, D. Bastieri, Liang-Liang Wang, Jie Zhang, Teresa Montaruli, Cong Li, Y. Li, K. Levochkin, X. J. Bi, T. X. Zeng, Chao-Peng Wang, J. W. Zhang, S. Z. Chen, H. Liu, X. D. Sheng, Yu. V. Stenkin, C. Hou, H. Zhu, Z. K. Zeng, P. P. Zhang, P. F. Zhang, Wenwu Tian, W. J. Long, Lanqing Ma, G. G. Xin, S. H. Feng, X. Y. Wang, X. Zuo, J. C. Wang, W. H. Wang, R. Zhou, N. Yin, H. B. Hu, C. F. Feng, S. M. Liu, X. T. Huang, Yi Zhang, N. Cheng, Cheng Li, Ying Zhang, Hong-Jie Li, H. Li, Y. Zheng, M. L. Chen, Axikegu, S. B. Yang, S. W. Cui, F. Ji, J. H. Fan, Y. Z. Fan, Bo-Qiang Ma, C. W. Yang, L. Feng, Z. G. Dai, L. Z. Zhao, L. Q. Yin, Wang Yingjie, Wei Liu, Zujian Wang, Z. Li, W. Zeng, Shengxue Zhang, Q. B. Gou, Huihai He, M. H. Gu, J. Fang, X. L. Chen, H. G. Wang, O. Shchegolev, S. L. He, K. Jiang, F. Zheng, T. L. Chen, W. Gao, T. Wen, L. Shao, Yucheng Feng, M. Y. Qi, X. X. Zhou, Yiwei Wang, Felix Aharonian, K. Li, Y. F. Liang, Ruizhi Yang, Y. W. Bao, David Ruffolo, Z. Y. You, S. Hu, J. Y. Liu, Ming Chen, Warit Mitthumsiri, V. Stepanov, Q. An, Q. Gao, K. J. Zhu, Z. B. Sun, P. H. T. Tam, Y. Q. Guo, H. R. Wu, B. Z. Dai, D. Liu, M. Heller, Sina Chen, H. D. Zeng, X. H. You, Renxin Xu, C. G. Zhu, Minghui Liu, X. H. Ma, Y. He, J. R. Shi, Yuan-Ming Xing, F. F. Yang, X. X. Li, W. L. Li, Q. H. Chen, D. della Volpe, Huang Qiyan, A. Masood, H. Cai, and Alejandro Sáiz
Subjects: Nuclear and High Energy Physics, Active galactic nucleus, Cherenkov detector, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, High Energy Physics - Experiment, law.invention, Hochenergie-Astrophysik Theorie - Abteilung Hinton, High Energy Physics - Experiment (hep-ex), Observatory, law, 0103 physical sciences, 010306 general physics, Instrumentation, media_common, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Order (ring theory), Astronomy and Astrophysics, Projection (relational algebra), Air shower, Sky, High Energy Physics::Experiment, Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing)
Abstract: The Water Cherenkov Detector Array (WCDA) is a major component of the Large High Altitude Air Shower Array Observatory (LHAASO), a new generation cosmic-ray experiment with unprecedented sensitivity, currently under construction. The WCDA is aimed at the study of TeV $\gamma$-rays. In order to evaluate the prospects of searching for TeV $\gamma$-ray sources with the WCDA, we present in this paper a projection for the one-year sensitivity of the WCDA to TeV $\gamma$-ray sources from TeVCat (footnote: http://tevcat.uchicago.edu) using an all-sky approach. Out of 128 TeVCat sources observable to the WCDA up to a zenith angle of $45^\circ$, we estimate that 42 would be detectable for one year of observations at a median energy of 1 TeV. Most of them are Galactic sources, and the extragalactic sources are Active Galactic Nuclei (AGN)., Comment: 10 pages,10 figures, it is to be published in Chinese Physics C
Published: 2020
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14. 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

15. Intrinsic linearity of bakelite Resistive Plate Chambers operated in streamer mode

Author: M. Iacovacci, L. L. Ma, X. H. Ma, Hongbo Hu, X. Y. Zhang, Minghui Liu, L. Perrone, Zihuang Cao, P. Creti, Haifeng Li, R. Santonico, Yicheng Guo, J. B. Zhao, P. Salvini, A. Budano, Chang-Chun Ning, Cunfeng Feng, Zhaoyang Feng, Fudong Shi, Z. G. Yao, C. Y. Wu, B. D'Ettorre Piazzoli, H. Lu, F. R. Zhu, S. Mastroianni, Danzengluobu, G. Di Sciascio, I. De Mitri, S. M. Mari, X. C. Yang, Piero Vallania, T. L. Chen, Zhaxiciren, G. Liguori, L. Xue, Paolo Camarri, Zhenyong Feng, B. Bartoli, C. X. Liu, H. W. Wang, Zhaxisangzhu, J. K. K. Liu, H. Y. Jia, Longzhou Zhang, Q. Q. Zhu, M. Zha, X. J. Bi, M. Panareo, G. Mancarella, S. W. Cui, S. Z. Chen, T. Di Girolamo, H. R. Wu, B. Z. Dai, F. Ruggieri, P. Branchini, Q. B. Gou, A. F. Yuan, Labaciren, Q. Y. Yang, G. Zizzi, H. H. He, Y. H. Tan, A. D'Amone, X. D. Sheng, Paolo Bernardini, Paolo Montini, R. Iuppa, R. Cardarelli, G. Marsella, S. Vernetto, Pengnian Shen, S. Catalanotti, P. Pistilli, H. M. Zhang, X. X. Zhou, A. Surdo, Carlo Vigorito, Haibing Hu, Y. Zhang, D. Martello, Bartoli B., Bernardini P., Bi X. J., Branchini P., Budano A., Camarri P., Cao Z., Cardarelli R., Catalanotti S., Chen S. Z., Chen T. L., Creti P., Cui S. W., Dai B. Z., D'Amone A., Danzengluobu, De Mitri I., D'Ettorre Piazzoli B., Di Girolamo T., Di Sciascio G., Feng C. F., Feng Z., Gou Q. B., Guo Y. Q., He H. H., Hu H., Iacovacci M., Iuppa R., Jia H. Y., Labaciren, Li H. J., Liguori G., Liu C., Liu J., Liu M. Y., Lu H., Ma L. L., Ma X. H., Mancarella G., Mari S. M., Marsella G., Martello D., Mastroianni S., Montini P., Ning C. C., Panareo M., Perrone L., Pistilli P., Ruggieri F., Salvini P., Santonico R., Shen P. R., Sheng X. D., Shi F., Surdo A., Tan Y. H., Vallania P., Vernetto S., Vigorito C., Wang H., Wu C. Y., Wu H. R., Xue L., Yang Q. Y., Yang X. C., Yao Z. G., Yuan A. F., Zha M., Zhang H. M., Zhang L., Zhang X. Y., Zhang Y., Zhao J., Zhaxiciren Zhaxisangzhu, Zhou X. X., Zhu F. R., Zhu Q. Q., Zizzi G., Bartoli, B., Bernardini, P., Bi, X. J., Branchini, P., Budano, A., Camarri, P., Cao, Z., Cardarelli, R., Catalanotti, S., Chen, S. Z., Chen, T. L., Creti, P., Cui, S. W., Dai, B. Z., D'Amone, A., De Mitri, I., D'Ettorre Piazzoli, B., Di Girolamo, T., Di Sciascio, G., Feng, C. F., Feng, Z., Gou, Q. B., Guo, Y. Q., He, H. H., Hu, H., Iacovacci, M., Iuppa, R., Jia, H. Y., Li, H. J., Liguori, G., Liu, C., Liu, J., Liu, M. Y., Lu, H., Ma, L. L., Ma, X. H., Mancarella, G., Mari, S. M., Marsella, G., Martello, D., Mastroianni, S., Montini, P., Ning, C. C., Panareo, M., Perrone, L., Pistilli, P., Ruggieri, F., Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, H., Wu, C. Y., Wu, H. R., Xue, L., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M., Zhang, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhao, J., Zhaxiciren, Zhaxisangzhu, Zhou, X. X., Zhu, F. R., Zhu, Q. Q., Zizzi, G., D’Amone, A., Danzengluobu, Null, D’Ettorre Piazzoli, B., Feng, Zhaoyang, Feng, Zhenyong, Hu, Haibing, Hu, Hongbo, Labaciren, Null, Zhaxiciren, Null, and Zhaxisangzhu, Null
Subjects: Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Intrinsic linearity, Streamer mode, Cosmic ray, Calorimetry, 01 natural sciences, chemistry.chemical_compound, Optics, 0103 physical sciences, Bakelite, Particle density, 010303 astronomy & astrophysics, Instrumentation, Physics, Resistive touchscreen, 010308 nuclear & particles physics, business.industry, Detector, Settore FIS/01 - Fisica Sperimentale, Linearity, RPC detector, Streamer mode, Intrinsic linearity, Calorimetry, chemistry, Particle, Physics::Accelerator Physics, RPC detector, business, Beam (structure)
Abstract: Resistive Plate Chambers have largely been used in High Energy Physics and Cosmic Ray research. In view of using this detector for calorimetry applications it is important to know the maximum measurable particle density, or its intrinsic linearity limit, which is tightly related to the dimension of the discharge region. In this paper we report the results of measurements performed at the Beam Test Facility (INFN National Laboratory of Frascati, Italy) where the intrinsic linearity of bakelite RPCs operated in streamer mode has been tested at different impinging particle densities.
Published: 2019

16. A calibration of WFCTA prototype telescopes using N2 laser

Author: M. H. Gu, G. C. Xiao, S. H. Feng, Zihuang Cao, M. Zha, L. L. Ma, M. J. Chen, Bin Zhou, J. Liu, X. Zuo, H. Y. Jia, Bai Yibing, Bingshui Gao, Shengxue Zhang, C. Hou, J. B. Zhao, S. Z. Chen, B.K. Zhang, H. H. He, Y. Zhang, Jiali Liu, and F. R. Zhu
Subjects: Physics, Nuclear and High Energy Physics, Photon, 010308 nuclear & particles physics, business.industry, Scattering, Aperture, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Field of view, Laser, 01 natural sciences, law.invention, 010309 optics, Telescope, Optics, law, 0103 physical sciences, Calibration, business, Instrumentation
Abstract: An end-to-end calibration method, which is different from the traditional way, has been employed in WFCTA prototype experiment based on N 2 laser. As we known, the calculation of the expected and the observed light fluxes at the front of the aperture of the telescope are crucial in the such method. To calculate predicted light flux accurately, the propagation and scattering of photons in the atmosphere have been considered in detail. In order to get the detector effective areas, which will be used in the transformation of ADC signals to the observed light flux, a ray trace procedure, considering all details of detector response, has been performed for all incident direction of photons in field of view of the detector. By matching the observed and expected light flux at the entrance of the telescope, the overall calibration gains of two telescopes can be obtained. During the test run of the calibration, a overall calibration gain around G = 0 . 38 A D C c o u n t s ∕ p h o t o n and G = 0 . 36 A D C c o u n t s ∕ p h o t o n for WFCT01 and WFCT02 are given, respectively. Furthermore, in view of all uncertainty sources, systematic uncertainties for the calibration have also been estimated. They are around the level of ( − 7 . 3 % , + 7 . 8 % ) . The calibration results achieved by end-to-end method and the traditional way are in consistent at the level of 10%, which is within the range of uncertainties. Since the end-to-end and traditional calibration methods have their own advantages, the performance of the combination of these two calibration methods has also been discussed in the end.
Published: 2018

17. Absolute-energy-scale calibration of ARGO-YBJ for light primaries in multi-TeV region with the Moon shadow observation

Author: X. C. Yang, H. H. He, T. Di Girolamo, Zhenyong Feng, H. Y. Jia, B. D'Ettorre Piazzoli, L. Xue, Hong-peng Lu, P. Pistilli, H. M. Zhang, X. X. Zhou, M. Iacovacci, M. Zha, Labaciren, X. D. Sheng, S. M. Mari, J. K. K. Liu, A. Surdo, Paolo Bernardini, L. L. Ma, Haibing Hu, Longzhou Zhang, H. W. Wang, J. B. Zhao, P. Salvini, Chang-Chun Ning, C. X. Liu, H. J. Li, H. R. Wu, Zhaoyang Feng, G. Marsella, X. J. Bi, Y. Zhang, Z. G. Yao, G. Mancarella, Zhaxisangzhu, C. Y. Wu, B. Bartoli, S. Z. Chen, L. Perrone, R. Santonico, G. Di Sciascio, Y. H. Tan, Fudong Shi, B. Z. Dai, S. Mastroianni, Carlo Vigorito, Zhaxiciren, F. R. Zhu, Danzengluobu, Y. Q. Guo, Q. Q. Zhu, I. De Mitri, Q. B. Gou, Zihuang Cao, Piero Vallania, T. L. Chen, A. F. Yuan, Pengnian Shen, S. Catalanotti, S. W. Cui, Hongbo Hu, C. F. Feng, P. Montini, X. H. Ma, X. Y. Zhang, Minghui Liu, R. Iuppa, S. Vernetto, A. D'Amone, Q. Y. Yang, Bartoli, B., Bernardini, P., Bi, X. J., Cao, Z., Catalanotti, S., Chen, S. Z., Chen, T. L., Cui, S. W., Dai, B. Z., D'Amone, A., Danzengluobu, Null, De Mitri, I., D'Ettorre Piazzoli, B., Di Girolamo, T., Di Sciascio, G., Feng, C. F., Feng, Zhaoyang, Feng, Zhenyong, Gou, Q. B., Guo, Y. Q., He, H. H., Hu, Haibing, Hu, Hongbo, Iacovacci, M., Iuppa, R., Jia, H. Y., Labaciren, Null, Li, H. J., Liu, C., Liu, J., Liu, M. Y., Lu, H., Ma, L. L., Ma, X. H., Mancarella, G., Mari, Stefano Maria, Marsella, G., Mastroianni, S., Montini, Paolo, Ning, C. C., Perrone, L., Pistilli, Pio, Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, H., Wu, C. Y., Wu, H. R., Xue, L., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M, Zhang, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhao, J., Zhaxiciren, Null, Zhaxisangzhu, Null, Zhou, X. X., Zhu, F. R., Zhu, Q. Q., Bernardini, Paolo, D'Amone, Antonio, DE MITRI, Ivan, D’Ettorre Piazzoli, B., Mancarella, Giovanni, Mari, S. M., Marsella, Giovanni, Montini, P., Perrone, Lorenzo, Pistilli, P., Zha, M., and collaboration), (The ARGO YBJ
Subjects: Cosmic ray, Energy calibration, Energy spectrum, Moon shadow, Physics, Large Hadron Collider, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Moon shadow, Astronomy, Astronomy and Astrophysics, Cosmic ray, Interaction model, Astrophysics, 01 natural sciences, Scale error, Energy calibration, Energy spectrum, Rigidity (electromagnetism), 0103 physical sciences, Ultra-high-energy cosmic ray, 010303 astronomy & astrophysics, Argo
Abstract: In 2011 ARGO-YBJ experiment has reported a work to study the absolute rigidity scale of the primary cosmic ray particles based on the Moon's shadow observation. Given the progress in high energy hadronic interaction models with LHC data, in cosmic ray chemical composition measurement and in experimental data accumulation, more updates can be researched. This paper aims to further disentangle the composition dependence in absolute-energy-scale calibration by using specific moon-shadow data which mainly is comprised of light component cosmic rays. Results show that, 17% energy scale error is estimated from 3 TeV to 50 TeV. To validate the performance of this technique, the light component cosmic ray spectrum in the same energy region is shown. (C) 2017 Elsevier B.V. All rights reserved.
Published: 2017

18. Search for Gamma-Ray Emission from the Sun during Solar Minimum with the ARGO-YBJ Experiment

Author: C. Y. Wu, Labaciren, Q. Y. Yang, P. Montini, X. H. Ma, C. C. Ning, Haifeng Li, C. Q. Liu, Q. B. Gou, Q. Q. Zhu, L. Zhang, T. L. Chen, Danzengluobu, C. Vigorito, P. Bernardini, R. Santonico, Zhaxisangzhu, Hongbo Hu, Yicheng Guo, A. Surdo, Y. H. Tan, P. R. Shen, X. C. Yang, H. Y. Jia, H. R. Wu, S. Catalanotti, B. Z. Dai, J. Zhao, Huihai He, Zhaoyang Feng, F. R. Zhu, P. Pistilli, H. M. Zhang, H. Lu, Minghui Liu, G. Di Sciascio, X. Y. Zhang, Zihou Li, G. Mancarella, I. De Mitri, T. Di Girolamo, Zhaxiciren, Xiangdong Sheng, R. Iuppa, S. W. Cui, A. F. Yuan, S. Vernetto, S. Z. Chen, A. D'Amone, Cunfeng Feng, H. Wang, S. Mastroianni, Y. J. Zhang, Haibing Hu, B. Bartoli, X. J. Bi, L. Perrone, J. K. K. Liu, L. L. Ma, W. Gao, M. Zha, Zhenyong Feng, X. X. Zhou, P. Vallania, B. D'Ettorre Piazzoli, L. Xue, Z. G. Yao, M. Iacovacci, Zhengguo Cao, F. Shi, P. Salvini, G. Marsella, S. M. Mari, Bartoli B., Bernardini P., Bi X. J., Cao Z., Catalanotti S., Chen S. Z., Chen T. L., Cui S. W., Dai B. Z., D'Amone A., Danzengluobu, Mitri I. D., Piazzoli B. D., Girolamo T. D., Sciascio G. D., Feng C. F., Feng Z., Gao W., Gou Q. B., Guo Y. Q., He H. H., Hu H., Iacovacci M., Iuppa R., Jia H. Y., Labaciren, Li H. J., Li Z., Liu C., Liu J., Liu M. Y., Lu H., Ma L. L., Ma X. H., Mancarella G., Mari S. M., Marsella G., Mastroianni S., Montini P., Ning C. C., Perrone L., Pistilli P., Salvini P., Santonico R., Shen P. R., Sheng X. D., Shi F., Surdo A., Tan Y. H., Vallania P., Vernetto S., Vigorito C., Wang H., Wu C. Y., Wu H. R., Xue L., Yang Q. Y., Yang X. C., Yao Z. G., Yuan A. F., Zha M., Zhang H. M., Zhang L., Zhang X. Y., Zhang Y., Zhao J., Zhaxiciren Zhaxisangzhu, Zhou X. X., Zhu F. R., Zhu Q. Q., Bartoli, B., Bernardini, P., Bi, X. J., Cao, Z., Catalanotti, S., Chen, S. Z., Chen, T. L., Cui, S. W., Dai, B. Z., D'Amone, A., Mitri, I. D., Piazzoli, B. D., Girolamo, T. D., Sciascio, G. D., Feng, C. F., Feng, Z., Gao, W., Gou, Q. B., Guo, Y. Q., He, H. H., Hu, H., Iacovacci, M., Iuppa, R., Jia, H. Y., Li, H. J., Li, Z., Liu, C., Liu, J., Liu, M. Y., Lu, H., Ma, L. L., Ma, X. H., Mancarella, G., Mari, S. M., Marsella, G., Mastroianni, S., Montini, P., Ning, C. C., Perrone, L., Pistilli, P., Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, H., Wu, C. Y., Wu, H. R., Xue, L., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M., Zhang, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhao, J., Zhaxiciren, Zhaxisangzhu, Zhou, X. X., Zhu, F. R., Zhu, Q. Q., D’Amone, A., Danzengluobu, Null, Mitri, I. De, Piazzoli, B. D’Ettorre, Di Girolamo, T., Sciascio, G. Di, Feng, Zhaoyang, Feng, Zhenyong, Hu, Haibing, Hu, Hongbo, Labaciren, Null, Zhaxiciren, Null, and Zhaxisangzhu, Null
Subjects: Solar minimum, Sun: general, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, astroparticle physics, cosmic rays, gamma rays: general, 7. Clean energy, 01 natural sciences, Atmosphere, 0103 physical sciences, general [Sun], 010303 astronomy & astrophysics, Argo, cosmic ray, High Energy Astrophysical Phenomena (astro-ph.HE), Astroparticle physics, Physics, 010308 nuclear & particles physics, Settore FIS/01 - Fisica Sperimentale, Gamma ray, Astronomy, astroparticle physic, Astronomy and Astrophysics, 13. Climate action, Space and Planetary Science, High Energy Physics::Experiment, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, general [gamma rays]
Abstract: The hadronic interaction of cosmic rays with solar atmosphere can produce high energy gamma-rays. The gamma-ray luminosity is correlated both with the flux of primary cosmic rays and the intensity of the solar magnetic field. The gamma-rays below 200 GeV have been observed by Fermi without any evident energy cutoff. The bright gamma-ray flux above 100 GeV has been detected only during solar minimum. The only available data in the TeV range come from the HAWC observations, however, outside the solar minimum. The ARGO-YBJ data set has been used to search for sub-TeV/TeV gamma-rays from the Sun during the solar minimum from 2008 to 2010, the same time period covered by the Fermi data. A suitable model containing the Sun shadow, solar disk emission, and inverse-Compton emission has been developed, and the chi-square minimization method was used to quantitatively estimate the disk gamma-ray signal. The result shows that no significant gamma-ray signal is detected and upper limits to the gamma-ray flux at 0.3-7 TeV are set at the 95% confidence level. In the low energy range these limits are consistent with the extrapolation of the Fermi-LAT measurements taken during solar minimum and are compatible with a softening of the gamma-ray spectrum below 1 TeV. They also provide an experimental upper bound to any solar disk emission at TeV energies. Models of dark matter annihilation via long-lived mediators predicting gamma-ray fluxes >10-7 GeV cm-2 s-1 below 1 TeV are ruled out by the ARGO-YBJ limits.
Published: 2019

19. 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

20. The Origin of Strong Linear Polarization from Fast Radio Bursts

Author: F. R. Zhu, R. N. Wang, Siming Liu, Anda Xiong, and Q. H. Chen
Subjects: Physics, Guiding center, 010504 meteorology & atmospheric sciences, Fast radio burst, Linear polarization, FOS: Physical sciences, Astronomy and Astrophysics, Electron, 01 natural sciences, Charged particle, Magnetic field, Computational physics, High Energy Physics - Phenomenology, Dipole, Neutron star, High Energy Physics - Phenomenology (hep-ph), Space and Planetary Science, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: The detection of almost 100% linearly polarized emission from the fast radio burst source FRB 121102 implies coherent emission of relativistic electrons moving perpendicular to the ambient magnetic field. The origin of such a particle distribution is very intriguing. Given that FRB 121102 is likely driven by a neutron star, we explored orbits of charged particles trapped in a dipole magnetic field (the Störmer problem). Most previous studies focused on particles with relatively low energies so that the guiding center approximation may be applied. High-energy particles usually have chaotic orbits except those on a periodic orbit or near stable periodic orbits. Via evaluation of the maximum Lyapunov exponent of orbits of particles launched from the equatorial plane with an axial velocity (the angular velocity sets the length and energy scales of the system), we found prominent regions of quasi-periodic orbits around stable periodic orbits in the equatorial plane at high energies. Particles in these orbits oscillate around the equatorial plane and their radial distance from the dipole can vary by a factor of ∼2. Relativistic electrons in such orbits may be responsible for the almost 100% polarized emission from FRB 121102.
Published: 2021

21. 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

22. The ARGO-YBJ experiment in Tibet

Author: THE ARGO YBJ COLLABORATION G. Aielli a, b, C. Bacci c, d, B. Bartoli e, f, P. Bernardini g, h, X. J. Bi i, C. Bleve g, P. Branchini d, A. Budano d, S. Bussino c, A. K. Calabrese Melcarne x, P. Camarri a, Z. Cao i, A. Cappa j, k, R. Cardarelli b, S. Catalanotti f, e, C. Cattaneo l, P. Celio c, S. Z. Chen i, Y. Chen i, N. Cheng i, P. Creti h, S. W. Cuim, B. Z. Dai o, G. D’Alí Staiti n, p, Danzengluobu q, M. Dattoli j, k, r, I. De Mitri g, B. D’Ettorre Piazzoli f, M. De Vincenzi c, T. Di Girolamo f, X. H. Ding q, G. Di Sciascio b, C. F. Feng s, Zhaoyang Feng i, Zhenyong Feng t, F. Galeazzi d, P. Galeotti j, r, R. Gargana d, Q. B. Gou i, Y. Q. Guo i, H. H. He i, Haibing Huq, Hongbo Hui, Q. Huang t, M. Iacovacci f, R. Iuppa a, I. James c, H. Y. Jia t, Labaciren q, H. J. Li q, J. Y. Li s, X. X. Li i, B. Liberti b, G. Liguori l, u, C. Liu i, C. Q. Liu o, M. Y. Lium, J. Liu o, H. Lui, X. H. Mai, G. Mancarella g, c, d, G. Marsella h, v, D. Martello g, S. Mastroianni e, X. R. Meng q, P. Montini c, C. C. Ning q, A. Pagliaro n, w, M. Panareo h, L. Perrone h, P. Pistilli c, X. B. Qu s, E. Rossi e, F. Ruggieri d, L. Saggese f, P. Salvini l, R. Santonico a, P. R. Shen i, X. D. Sheng i, F. Shi i, C. Stanescu d, A. Surdo h, Y. H. Tan i, P. Vallania j, S. Vernetto j, C. Vigorito j, B. Wangi, H. Wang i, C. Y. Wui, H. R. Wui, B. Xut, L. Xues, Y. X. Yanm, Q. Y. Yang o, X. C. Yang o, A. F. Yuan q, M. Zha i, H. M. Zhang i, JiLong Zhang i, JianLi Zhang i, L. Zhang o, P. Zhang o, X. Y. Zhang s, Y. Zhang i, Zhaxisangzhu q, X. X. Zhou t, F. R. Zhu i, Q. Q. Zhu i, G. Zizzi g, MARI, Stefano Maria, D'ALI' STAITI G, Aielli, G, Bacci, C, Bartoli, B, Bernardini, P, Bi, Xj, Bleve, C, Branchini, P, Budano, A, Bussino, Severino Angelo Maria, Calabrese Melcarne, Ak, Camarri, P, Cao, Z, Cappa, A, Cardarelli, R, Catalanotti, S, Cattaneo, C, Celio, P, Chen, Sz, Chen, Tl, Chen, Y, Cheng, N, Creti, P, Cui, Sw, Dai, Bz, D'Ali Staiti, G, Danzengluobu, Dattoli, M, De Mitri, I, D'Ettorre Piazzoli, B, De Vincenzi, M, Di Girolamo, T, Ding, Xh, Di Sciascio, G, Feng, Cf, Feng Zhao, Yang, Feng Zhen, Yong, Galeazzi, F, Galeotti, P, Gargana, R, Gou, Qb, Guo, Yq, He, Hh, Hu, Haibing, Hu Hong, Bo, Huang, Q, Iacovacci, M, Iuppa, R, James, I, Jia, Hy, Labaciren, Li, Hj, Li, Jy, Li, Xx, Liberti, B, Liguori, G, Liu, C, Liu, Cq, Liu, My, Liu, J, Lu, H, Ma, Xh, Mancarella, G, Mari, Stefano Maria, Marsella, G, Martello, D, Mastroianni, S, Meng, Xr, Montini, P, Ning, Cc, Pagliaro, A, Panareo, M, Perrone, L, Pistilli, P, Qu, Xb, Rossi, E, Ruggieri, F, Saggese, L, Salvini, P, Santonico, R, Shen, Pr, Sheng, Xd, Shi, F, Stanescu, C, Surdo, A, Tan, Yh, Vallania, P, Vernetto, S, Vigorito, C, Wang, B, Wang, H, Wu, Cy, Wu, Hr, Xu, B, Xue, L, Yan, Yx, Yang, Qy, Yang, Xc, Yuan, Af, Zha, M, Zhang, Hm, Zhang Ji, Long, Zhang Jian, Li, Zhang, L, Zhang, P, Zhang, Xy, Zhang, Y, Zhaxisangzhu, Zhou, Xx, Zhu, Fr, Zhu, Qq, Zizzi, G., G., Aielli, C., Bacci, F., Barone, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, P., Branchini, A., Budano, S., Bussino, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, A., Cappa, R., Cardarelli, S., Catalanotti, C., Cattaneo, S., Cavaliere, P., Celio, S. Z., Chen, N., Cheng, P., Creti, S. W., Cui, G., Cusumano, B. Z., Dai, G., D’Alí Staiti, M., Dattoli, DE MITRI, Ivan, R., De Rosa, B., D’Ettorre Piazzoli, M., De Vincenzi, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, C., Ferrigno, F., Galeazzi, P., Galeotti, X. Y., Gao, R., Gargana, F., Garufi, Q. B., Gou, H. H., He, Haibing, Hu, Hongbo, Hu, Q., Huang, M., Iacovacci, I., Jame, H. Y., Jia, H. J., Li, J. Y., Li, B., Liberti, G., Liguori, C. Q., Liu, J., Liu, H., Lu, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, X. R., Meng, J., Mu, L., Nicastro, C. C., Ning, L., Palummo, Panareo, Marco, Perrone, Lorenzo, P., Pistilli, X. B., Qu, E., Rossi, F., Ruggieri, L., Saggese, P., Salvini, R., Santonico, A., Segreto, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, H., Wang, Y. G., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, H. T., Yang, Q. Y., Yang, X. C., Yang, G. C., Yu, A. F., Yuan, M., Zha, H. M., Zhang, J. L., Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, G., Zizzi, THE ARGO YBJ COLLABORATION G., Aielli a, B, C., Bacci c, D, B., Bartoli e, F, P., Bernardini g, H, X. J., Bi i, C., Bleve g, P., Branchini d, A., Budano d, S., Bussino c, A. K., Calabrese Melcarne x, P., Camarri a, Z., Cao i, A., Cappa j, K, R., Cardarelli b, S., Catalanotti f, E, C., Cattaneo l, P., Celio c, S. Z., Chen i, Y., Chen i, N., Cheng i, P., Creti h, S. W., Cuim, B. Z., Dai o, G., D’Alí Staiti n, P, Danzengluobu, Q, M., Dattoli j, K, R, I., De Mitri g, B., D’Ettorre Piazzoli f, M., De Vincenzi c, T., Di Girolamo f, X. H., Ding q, G., Di Sciascio b, Zhaoyang Feng, I, Zhenyong Feng, T, F., Galeazzi d, P., Galeotti j, R, R., Gargana d, Q. B., Gou i, Y. Q., Guo i, H. H., He i, Haibing, Huq, Hongbo, Hui, Q., Huang t, M., Iacovacci f, R., Iuppa a, I., James c, H. Y., Jia t, Labaciren, Q, H. J., Li q, X. X., Li i, B., Liberti b, G., Liguori l, U, C., Liu i, C. Q., Liu o, M. Y., Lium, J., Liu o, H., Lui, X. H., Mai, G., Mancarella g, C, D, G., Marsella h, V, D., Martello g, S., Mastroianni e, X. R., Meng q, P., Montini c, C. C., Ning q, A., Pagliaro n, W, M., Panareo h, L., Perrone h, P., Pistilli c, E., Rossi e, F., Ruggieri d, L., Saggese f, P., Salvini l, R., Santonico a, P. R., Shen i, X. D., Sheng i, F., Shi i, C., Stanescu d, A., Surdo h, Y. H., Tan i, P., Vallania j, S., Vernetto j, C., Vigorito j, B., Wangi, H., Wang i, C. Y., Wui, H. R., Wui, B., Xut, Y. X., Yanm, Q. Y., Yang o, X. C., Yang o, A. F., Yuan q, M., Zha i, H. M., Zhang i, JiLong Zhang, I, JianLi Zhang, I, L., Zhang o, P., Zhang o, Y., Zhang i, Zhaxisangzhu, Q, X. X., Zhou t, F. R., Zhu i, Q. Q., Zhu i, and G., Zizzi g
Subjects: Physics, Nuclear and High Energy Physics, Gamma ray burst, Single cluster, Trigger rate, Detector, gamma ray bursts, gamma rays, cosmic rays, extended air showers, Astronomy, Sampling (statistics), Cosmic ray, Extended air showers, Cosmic rays, Gamma ray sources, Gamma ray bursts, Gamma ray sources, Geodesy, Guard ring, Extended air shower, Sampling density, Instrumentation, Argo
Abstract: The setting up of the ARGO detector at the YangBaJing Cosmic Ray Laboratory (4300 m a.s.l., Tibet, P.R. China) has been completed during the last spring (2007). It consists of a central carpet made of 130 identical sub-units of 12 RPCs each (a "cluster"), covering a surface of about 5800 m2 with 93% active area, and a guard ring of 24 further clusters of the same type surrounding the central carpet with a lower sampling density. Signals are picked up by external electrodes of small size, thus allowing the sampling of EAS with high space-time granularity. Shower events are detected at a trigger rate of about 4 kHz. Events with a few particles detected by a single cluster are counted in scaler mode on a time base of 500 ms. The intrinsic modularity of the ARGO detector allowed us to collect data even during the setting-up period, using only the central carpet (or even part of it). Some preliminary results from the analysis of events collected in a few months of data taking are presented. © 2008 Elsevier B.V. All rights reserved.
Published: 2008

23. The analog Resistive Plate Chamber detector of the ARGO-YBJ experiment

Author: Zihuang Cao, M. Iacovacci, M. Zha, J. W. Zhao, P. Pistilli, H. M. Zhang, Paolo Camarri, X. X. Zhou, J. K. K. Liu, X. Y. Zhang, P. Creti, Haibing Hu, Minghui Liu, Hongbo Hu, Haifeng Li, A. Surdo, Y. Zhang, D. Martello, Lanqing Ma, Yicheng Guo, Danzengluobu, Carlo Vigorito, S. W. Cui, P. Montini, X. H. Ma, Q. Q. Zhu, G. Di Sciascio, H. W. Wang, Zhaxisangzhu, A. Budano, H. Y. Jia, Fudong Shi, Labaciren, S. Mastroianni, Zhaxiciren, T. Di Girolamo, A. F. Yuan, G. Liguori, C. X. Liu, H. R. Wu, B. Z. Dai, F. Ruggieri, Q. Y. Yang, G. Zizzi, P. Branchini, R. Santonico, A. D'Amone, F. R. Zhu, S. Vernetto, H. Lu, R. Cardarelli, G. Marsella, L. Perrone, L. Zhang, P. Salvini, Cunfeng Feng, P. Bernardini, Y. H. Tan, Z. G. Yao, X. D. Sheng, Giovanni Mancarella, H. H. He, X. C. Yang, Chang-Chun Ning, Zhaoyang Feng, M. Panareo, P. Vallania, B. D'Ettorre Piazzoli, I. De Mitri, C. Y. Wu, L. Xue, Q. B. Gou, T. L. Chen, Zhenyong Feng, X. J. Bi, S. Z. Chen, B. Bartoli, S. M. Mari, Pengnian Shen, S. Catalanotti, R. Iuppa, ITA, Bartoli, Bruno, Bernardini, P., Bi, X. J., Branchini, P., Budano, A., Camarri, P., Cao, Z., Cardarelli, R., Catalanotti, Sergio, Chen, S. Z., Chen, T. L., Creti, P., Cui, S. W., Dai, B. Z., D’Amone, A., Danzengluobu, Null, De Mitri, I., D'ETTORRE PIAZZOLI, Benedetto, DI GIROLAMO, Tristano, Di Sciascio, G., Feng, C. F., Feng, Zhaoyang, Feng, Zhenyong, Gou, Q. B., Guo, Y. Q., He, H. H., Hu, Haibing, Hu, Hongbo, Iacovacci, Michele, Iuppa, R., Jia, H. Y., Labaciren, Null, Li, H. J., Liguori, G., Liu, C., Liu, J., Liu, M. Y., Lu, H., Ma, L. L., Ma, X. H., Mancarella, G., Mari, S. M., Marsella, G., Martello, D., Mastroianni, S., Montini, P., Ning, C. C., Panareo, M., Perrone, L., Pistilli, P., Ruggieri, F., Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, H., Wu, C. Y., Wu, H. R., Xue, L., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M., Zhang, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhao, J., Zhaxiciren, Null, Zhaxisangzhu, Null, Zhou, X. X., Zhu, F. R., Zhu, Q. Q., Zizzi, G., B. Bartoli, BERNARDINI, Paolo, X. J. Bi, P. Branchini, A. Budano, P. Camarri, Z. Cao, R. Cardarelli, S. Catalanotti, S. Z. Chen, T. L. Chen, P. Creti, S. W. Cui, B. Z. Dai, D'AMONE, ANTONIO, Danzengluobu, DE MITRI, Ivan, B. D’Ettorre Piazzoli, T. Di Girolamo, G. Di Sciascio, C. F. Feng, Zhaoyang Feng, Zhenyong Feng, Q. B. Gou, Y. Q. Guo, H. H. He, Haibing Hu, Hongbo Hu, M. Iacovacci, R. Iuppa, H. Y. Jia, Labaciren, H. J. Li, G. Liguori, C. Liu, J. Liu, M. Y. Liu, H. Lu, L. L. Ma, X. H. Ma, MANCARELLA, Giovanni, S. M. Mari, MARSELLA, GIOVANNI, MARTELLO, Daniele, S. Mastroianni, P. Montini, C. C. Ning, PANAREO, Marco, PERRONE, Lorenzo, P. Pistilli, F. Ruggieri, P. Salvini, R. Santonico, P. R. Shen, X. D. Sheng, F. Shi, A. Surdo, Y. H. Tan, P. Vallania, S. Vernetto, C. Vigorito, H. Wang, C. Y. Wu, H. R. Wu, L. Xue, Q. Y. Yang, X. C. Yang, Z. G. Yao, A. F. Yuan, M. Zha, H. M. Zhang, L. Zhang, X. Y. Zhang, Y. Zhang, J. Zhao, Zhaxiciren, Zhaxisangzhu, X. X. Zhou, F. R. Zhu, Q. Q. Zhu, G. Zizzi, B., Bartoli, Bernardini, Paolo, X. J., Bi, P., Branchini, A., Budano, P., Camarri, Z., Cao, R., Cardarelli, S., Catalanotti, S. Z., Chen, T. L., Chen, P., Creti, S. W., Cui, B. Z., Dai, D'Amone, Antonio, B., D’Ettorre Piazzoli, T., Di Girolamo, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Hu, Hongbo, Hu, M., Iacovacci, R., Iuppa, H. Y., Jia, H. J., Li, G., Liguori, C., Liu, J., Liu, M. Y., Liu, H., Lu, L. L., Ma, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, Panareo, Marco, Perrone, Lorenzo, P., Pistilli, F., Ruggieri, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, H., Wang, C. Y., Wu, H. R., Wu, L., Xue, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhang, J., Zhao, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, G., Zizzi, Mari, Stefano Maria, and The ARGO YBJ, Collaboration
Subjects: Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Air shower detection, FOS: Physical sciences, Cosmic ray, STRIPS, Calorimetry, Signal, law.invention, Optics, Observatory, law, Air shower detection, RPC detector, Calorimetry, Cosmic-ray observatory, physics.ins-det, Instrumentation and Methods for Astrophysics (astro-ph.IM), Physics, Resistive touchscreen, business.industry, Detector, Settore FIS/01 - Fisica Sperimentale, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Instrumentation and Detectors (physics.ins-det), Core (optical fiber), RPC detector, business, Astrophysics - Instrumentation and Methods for Astrophysics, astro-ph.IM
Abstract: The ARGO-YBJ experiment has been in stable data taking from November 2007 till February 2013 at the YangBaJing Cosmic Ray Observatory (4300 m a.s.l.). The detector consists of a single layer of Resistive Plate Chambers (RPCs) (6700 m2) operated in streamer mode. The signal pick-up is obtained by means of strips facing one side of the gas volume. The digital readout of the signals, while allows a high space–time resolution in the shower front reconstruction, limits the measurable energy to a few hundred TeV. In order to fully investigate the 1–10 PeV region, an analog readout has been implemented by instrumenting each RPC with two large size electrodes facing the other side of the gas volume. Since December 2009 the RPC charge readout has been in operation on the entire central carpet (∼5800 m2). In this configuration the detector is able to measure the particle density at the core position where it ranges from tens to many thousands of particles per m2. Thus ARGO-YBJ provides a highly detailed image of the charge component at the core of air showers. In this paper we describe the analog readout of RPCs in ARGO-YBJ and discuss both the performance of the system and the physical impact on the EAS measurements. The ARGO-YBJ experiment has been in stable data taking from November 2007 till February 2013 at the YangBaJing Cosmic Ray Observatory (4300 m a.s.l.). The detector consists of a single layer of Resistive Plate Chambers (RPCs) (6700 m2) operated in streamer mode. The signal pick-up is obtained by means of strips facing one side of the gas volume. The digital readout of the signals, while allows a high space-time resolution in the shower front reconstruction, limits the measurable energy to a few hundred TeV. In order to fully investigate the 1-10 PeV region, an analog readout has been implemented by instrumenting each RPC with two large size electrodes facing the other side of the gas volume. Since December 2009 the RPC charge readout has been in operation on the entire central carpet (â¼5800 m2). In this configuration the detector is able to measure the particle density at the core position where it ranges from tens to many thousands of particles per m2. Thus ARGO-YBJ provides a highly detailed image of the charge component at the core of air showers. In this paper we describe the analog readout of RPCs in ARGO-YBJ and discuss both the performance of the system and the physical impact on the EAS measurements.
Published: 2015

24. Lomb–Scargle periodogram analysis of the periods around 5.5 year and 11 year in the international sunspot numbers

Author: F. R. Zhu and H. Y. Jia
Subjects: Physics, Sunspot, 010504 meteorology & atmospheric sciences, Least-squares spectral analysis, Space and Planetary Science, Climatology, 0103 physical sciences, Periodogram, Astronomy and Astrophysics, 010303 astronomy & astrophysics, 01 natural sciences, 0105 earth and related environmental sciences
Abstract: The New International Sunspot Numbers (NISNs) have been successfully compiled and can be downloaded from the World Data Center-Sunspot index and Long-term Solar Observations, Royal Observatory of Belgium, Brussels. The periods in these NISNs have been studied by using the Lomb–Scargle periodogram. The results show that the international sunspot numbers have a lot of periods. Of the various periods, the most outstanding period around 11 year is 10.108 year after removing the 10.862 year signal from the time series of sunspot numbers, while the periods of 11.988 year, 7.990 year, 9.612 year, 5.445 year, 8.915 year, 5.792 year are also found with the period of 5.445 year being stronger than those of 5.792 year and 8.915 year. However, the period of 5.445 year is still much weaker than the period of 10.862 year. It is evident that the periods around 11 year and 5.5 year in the revised international sunspot numbers obtained by using the Lomb–Scargle periodogram method is somewhat different from the ones in previous studies.
Published: 2018

25. Galactic Cosmic-Ray Anisotropy in the Northern hemisphere from the ARGO-YBJ Experiment during 2008-2012

Author: J. Zhao, Hongbo Hu, P. R. Shen, X. C. Yang, A. Surdo, Yicheng Guo, Y. H. Tan, Zhaoyang Feng, F. R. Zhu, X. J. Bi, T. Di Girolamo, J. K. K. Liu, S. Vernetto, Zhaxisangzhu, Zhengguo Cao, S. Z. Chen, Q. Q. Zhu, L. Zhang, T. L. Chen, R. Santonico, S. Mastroianni, C. Vigorito, C. Y. Wu, S. W. Cui, C. Q. Liu, Q. B. Gou, C. C. Ning, P. Vallania, F. Shi, S. M. Mari, B. D'Ettorre Piazzoli, A. D'Amone, H. J. Li, H. R. Wu, Zhaxiciren, R. Iuppa, L. Xue, P. Salvini, G. Marsella, W. Gao, P. Bernardini, H. Wang, H. Lu, Danzengluobu, S. Catalanotti, David Ruffolo, A. F. Yuan, B. Z. Dai, Y. J. Zhang, Huihai He, M. Zha, G. Di Sciascio, X. Y. Zhang, Labaciren, Xiangdong Sheng, P. Pistilli, H. M. Zhang, Minghui Liu, I. De Mitri, Q. Y. Yang, P. Montini, X. H. Ma, X. X. Zhou, L. Perrone, Haibing Hu, L. L. Ma, H. Y. Jia, G. Mancarella, B. Bartoli, Cunfeng Feng, M. Iacovacci, Z. G. Yao, Bartoli, B., Bernardini, P., Bi, X. J., Cao, Z., Catalanotti, S., Chen, S. Z., Chen, T. L., Cui, S. W., Dai, B. Z., D’Amone, A., Danzengluobu, Null, De Mitri, I., Piazzoli, B. D’Ettorre, Di Girolamo, T., Di Sciascio, G., Feng, C. F., Feng, Z. Y., Gao, W., Gou, Q. B., Guo, Y. Q., He, H. H., Hu, Haibing, Hu, Hongbo, Iacovacci, M., Iuppa, R., Jia, H. Y., Labaciren, Null, Li, H. J., Liu, C., Liu, J., Liu, M. Y., Lu, H., Ma, L. L., Ma, X. H., Mancarella, G., Mari, S. M., Marsella, G., Mastroianni, S., Montini, P., Ning, C. C., Perrone, L., Pistilli, P., Ruffolo, D., Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, H., Wu, C. Y., Wu, H. R., Xue, L., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M., Zhang, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhao, J., Zhaxiciren, Null, Zhaxisangzhu, Null, Zhou, X. X., Zhu, F. R., Zhu, Q. Q., D'Amone, A., Piazzoli, B. D'Ettorre, Mastroianni, Stefano, Danzengluobu, null, Labaciren, null, Zhaxiciren, null, and Zhaxisangzhu, null
Subjects: Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, 01 natural sciences, cosmic rays, 0103 physical sciences, Anisotropy, 010303 astronomy & astrophysics, Argo, cosmic ray, Astroparticle physics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Settore FIS/01 - Fisica Sperimentale, Northern Hemisphere, Astronomy, astroparticle physic, Astronomy and Astrophysics, astroparticle physics, cosmic ray anysotropy, argo-ybj, Astronomy and Astrophysic, astroparticle physics, Space and Planetary Science, 13. Climate action, Astrophysics - High Energy Astrophysical Phenomena
Abstract: This paper reports on the observation of the sidereal large-scale anisotropy of cosmic rays using data collected by the ARGO-YBJ experiment over 5 years (2008-2012). This analysis extends previous work limited to the period from 2008 January to 2009 December, near the minimum of solar activity between cycles 23 and 24. With the new data sample, the period of solar cycle 24 from near minimum to maximum is investigated. A new method is used to improve the energy reconstruction, allowing us to cover a much wider energy range, from 4 to 520 TeV. Below 100 TeV, the anisotropy is dominated by two wide regions, the so-called “tail-in” and “loss-cone” features. At higher energies, a dramatic change of the morphology is confirmed. The yearly time dependence of the anisotropy is investigated. Finally, no noticeable variation of cosmic-ray anisotropy with solar activity is observed for a median energy of 7 TeV.
Published: 2018
Full Text: View/download PDF

26. Energy spectrum of cosmic protons and helium nuclei by a hybrid measurement at 4300 m a.s.l

Author: A. D'Amone, Bo Gao, Zhenyong Feng, Piero Vallania, Xu Wang, Q. Y. Yang, S. S. Zhang, J. W. Zhao, R. Santonico, Hongbo Hu, G. Zizzi, A. Surdo, C. F. Feng, M. Iacovacci, P. Creti, Paolo Camarri, A. K. Calabrese Melcarne, T. Di Girolamo, F. R. Zhu, B. D'Ettorre Piazzoli, X. J. Bi, S. N. Sbano, R. Cardarelli, S. Z. Chen, Y. H. Tan, X. Zuo, B. k. Zhang, P. Salvini, G. Marsella, Lanqing Ma, Labaciren, Paolo Montini, S. H. Feng, R. Iuppa, L. Xue, M. Zha, S. Vernetto, B. Panico, X. X. Li, L. Zhang, Hong-peng Lu, S. M. Mari, I. Bolognino, S. W. Cui, J. K. K. Liu, B. Z. Dai, I. De Mitri, F. Ruggieri, Zhen Cao, Chang-Chun Ning, Zhaoyang Feng, Y. Zhang, Danzengluobu, A. F. Yuan, T. L. Chen, Bin Zhou, Q. Q. Zhu, Q. B. Gou, Huihai He, Haibing Hu, G. Mancarella, C. Hou, P. Branchini, Ming Chen, H. Y. Jia, B. Bartoli, X. D. Sheng, Y. X. Bai, Paolo Bernardini, Pengnian Shen, S. Catalanotti, G. C. Xiao, D. Martello, L. Perrone, G. Di Sciascio, M. Panareo, X. C. Yang, Y. Q. Guo, C. Y. Wu, Carlo Vigorito, Y. B. Chen, H. J. Li, H. R. Wu, P. Pistilli, H. M. Zhang, Jiali Liu, X. X. Zhou, M. H. Gu, X. Y. Zhang, Minghui Liu, Zhaxisangzhu, Z. G. Yao, X. H. Ma, Zhaxiciren, H. W. Wang, A. Budano, Fudong Shi, S. Mastroianni, G. Liguori, C. X. Liu, B., Bartoli, Bernardini, Paolo, X. J., Bi, I., Bolognino, P., Branchini, A., Budano, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, R., Cardarelli, S., Catalanotti, S. Z., Chen, T. L., Chen, P., Creti, S. W., Cui, B. Z., Dai, D'Amone, Antonio, Danzengluobu, DE MITRI, Ivan, B., D'Ettorre Piazzoli, T., Di Girolamo, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Hu, Hongbo, Hu, M., Iacovacci, R., Iuppa, H. Y., Jia, Labaciren, H. J., Li, G., Liguori, C., Liu, J., Liu, M. Y., Liu, H., Lu, L. L., Ma, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, Panareo, Marco, B., Panico, Perrone, Lorenzo, P., Pistilli, F., Ruggieri, P., Salvini, R., Santonico, S. N., Sbano, P. R., Shen, X. D., Sheng, F., Shi, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, H., Wang, C. Y., Wu, H. R., Wu, L., Xue, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhang, J., Zhao, Zhaxiciren, Zhaxisangzhu, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, G., Zizzi, Y. X., Bai, M. J., Chen, Y., Chen, S. H., Feng, B., Gao, M. H., Gu, C., Hou, X. X., Li, J. L., Liu, X., Wang, G., Xiao, B. K., Zhang, S. S., Zhang, B., Zhou, X., Zuo, P., Bernardini, Catalanotti, Sergio, A., D'Amone, I., De Mitri, DI GIROLAMO, Tristano, Q., Huang, Iacovacci, Michele, B. Bartoli, BERNARDINI, Paolo, X. J. Bi, I. Bolognino, P. Branchini, A. Budano, A. K. Calabrese Melcarne, P. Camarri, Z. Cao, R. Cardarelli, S. Catalanotti, S. Z. Chen, T. L. Chen, P. Creti, S. W. Cui, B. Z. Dai, D'AMONE, ANTONIO, B. D'Ettorre Piazzoli, T. Di Girolamo, G. Di Sciascio, C. F. Feng, Zhaoyang Feng, Zhenyong Feng, Q. B. Gou, Y. Q. Guo, H. H. He, Haibing Hu, Hongbo Hu, M. Iacovacci, R. Iuppa, H. Y. Jia, H. J. Li, G. Liguori, C. Liu, J. Liu, M. Y. Liu, H. Lu, L. L. Ma, X. H. Ma, MANCARELLA, Giovanni, S. M. Mari, MARSELLA, GIOVANNI, MARTELLO, Daniele, S. Mastroianni, P. Montini, C. C. Ning, PANAREO, Marco, B. Panico, PERRONE, Lorenzo, P. Pistilli, F. Ruggieri, P. Salvini, R. Santonico, S. N. Sbano, P. R. Shen, X. D. Sheng, F. Shi, A. Surdo, Y. H. Tan, P. Vallania, S. Vernetto, C. Vigorito, H. Wang, C. Y. Wu, H. R. Wu, L. Xue, Q. Y. Yang, X. C. Yang, Z. G. Yao, A. F. Yuan, M. Zha, H. M. Zhang, L. Zhang, X. Y. Zhang, Y. Zhang, J. Zhao, X. X. Zhou, F. R. Zhu, Q. Q. Zhu, G. Zizzi, Y. X. Bai, M. J. Chen, Y. Chen, S. H. Feng, B. Gao, M. H. Gu, C. Hou, X. X. Li, J. L. Liu, X. Wang, G. Xiao, B. K. Zhang, S. S. Zhang, B. Zhou, and X. Zuo
Subjects: Nuclear and High Energy Physics, Hydrogen, Astrophysics::High Energy Astrophysical Phenomena, ARGO-YBJ, FOS: Physical sciences, chemistry.chemical_element, Cosmic ray, High Energy Physics - Experiment, law.invention, Nuclear physics, Telescope, High Energy Physics - Experiment (hep-ex), law, Instrumentation, Cherenkov radiation, Helium, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Range (particle radiation), COSMIC cancer database, Settore FIS/01 - Fisica Sperimentale, Astrophysics::Instrumentation and Methods for Astrophysics, Hybrid measurement, Astronomy and Astrophysics, Alpha particle, chemistry, Cherenkov telescope, Energy Spectrum, Astrophysics - High Energy Astrophysical Phenomena, Composition
Abstract: The energy spectrum of cosmic Hydrogen and Helium nuclei has been measured, below the so-called "knee", by using a hybrid experiment with a wide field-of-view Cherenkov telescope and the Resistive Plate Chamber (RPC) array of the ARGO-YBJ experiment at 4300 m above sea level. The Hydrogen and Helium nuclei have been well separated from other cosmic ray components by using a multi-parameter technique. A highly uniform energy resolution of about 25% is achieved throughout the whole energy range (100 TeV - 700 TeV). The observed energy spectrum is compatible with a single power law with index gamma=-2.63+/-0.06., Comment: To be published on Chinese Physics C
Published: 2014

27. Radon contribution to single particle counts of the ARGO-YBJ detector

Author: B. Bartoli a, b, P. Bernardini c, d, X. J. Bi e, I. Bolognino n, o, P. Branchini f, A. Budano f, P. Camarri g, h, Z. Cao e, R. Cardarelli h, S. Catalanotti a, C. Cattaneo o, S. Z. Chen e, T. L. Chen i, P. Creti d, S. W. Cui j, B. Z. Dai k, A. D'Amone c, Danzengluobu i, I. De Mitri c, B. D'Ettorre Piazzoli a, T. Di Girolamo a, G. Di Sciascio h, C. F. Feng l, Zhaoyang Feng e, Zhenyong Feng m, E. Giroletti n, Q. B. Gou e, Y. Q. Guo e, H. H. He e, Haibing Hu i, Hongbo Hu e, M. Iacovacci a, R. Iuppa g, H. Y. Jia m, Labaciren i, H. J. Li i, G. Liguori n, C. Liu e, J. Liu k, M. Y. Liu i, H. Lu e, L. L. Ma e, X. H. Ma e, G. Mancarella c, f, p, G. Marsella c, D. Martello c, S. Mastroianni b, P. Montini f, p, C. C. Ning i, M. Panareo c, L. Perrone c, P. Pistilli f, F. Ruggieri f, P. Salvini o, R. Santonico g, P. R. Shen e, X. D. Sheng e, F. Shi e, A. Surdo d, Y. H. Tan e, P. Vallania q, r, S. Vernetto q, C. Vigorito r, s, H. Wang e, C. Y. Wu e, H. R. Wu e, L. Xue l, Q. Y. Yang k, X. C. Yang k, Z. G. Yao e, A. F. Yuan i, M. Zha e, H. M. Zhang e, L. Zhang k, X. Y. Zhang l, Y. Zhang e, J. Zhao e, Zhaxiciren i, Zhaxisangzhu i, X. X. Zhou m, F. R. Zhu m, Q. Q. Zhu e, G. Zizzi t, The ARGO YBJ Collaboration, MARI, Stefano Maria, B., Bartoli a, B, P., Bernardini c, D, X. J., Bi e, I., Bolognino n, O, P., Branchini f, A., Budano f, P., Camarri g, H, Z., Cao e, R., Cardarelli h, S., Catalanotti a, C., Cattaneo o, S. Z., Chen e, T. L., Chen i, P., Creti d, S. W., Cui j, B. Z., Dai k, A., D'Amone c, Danzengluobu, I, I., De Mitri c, B., D'Ettorre Piazzoli a, T., Di Girolamo a, G., Di Sciascio h, C. F., Feng l, Zhaoyang Feng, E, Zhenyong Feng, M, E., Giroletti n, Q. B., Gou e, Y. Q., Guo e, H. H., He e, Haibing Hu, I, Hongbo Hu, E, M., Iacovacci a, R., Iuppa g, H. Y., Jia m, Labaciren, I, H. J., Li i, G., Liguori n, C., Liu e, J., Liu k, M. Y., Liu i, H., Lu e, L. L., Ma e, X. H., Ma e, G., Mancarella c, Mari, Stefano Maria, F, P, G., Marsella c, D., Martello c, S., Mastroianni b, P., Montini f, P, C. C., Ning i, M., Panareo c, L., Perrone c, P., Pistilli f, F., Ruggieri f, P., Salvini o, R., Santonico g, P. R., Shen e, X. D., Sheng e, F., Shi e, A., Surdo d, Y. H., Tan e, P., Vallania q, R, S., Vernetto q, C., Vigorito r, S, H., Wang e, C. Y., Wu e, H. R., Wu e, L., Xue l, Q. Y., Yang k, X. C., Yang k, Z. G., Yao e, A. F., Yuan i, M., Zha e, H. M., Zhang e, L., Zhang k, X. Y., Zhang l, Y., Zhang e, J., Zhao e, Zhaxiciren, I, Zhaxisangzhu, I, X. X., Zhou m, F. R., Zhu m, Q. Q., Zhu e, G., Zizzi t, The ARGO YBJ, Collaboration, B., Bartoli, Bernardini, Paolo, X. J., Bi, I., Bolognino, P., Branchini, A., Budano, P., Camarri, Z., Cao, R., Cardarelli, S., Catalanotti, C., Cattaneo, S. Z., Chen, T. L., Chen, P., Creti, S. W., Cui, B. Z., Dai, D'Amone, Antonio, Danzengluobu, DE MITRI, Ivan, B., D'Ettorre Piazzoli, T., Di Girolamo, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, E., Giroletti, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Hu, Hongbo, Hu, M., Iacovacci, R., Iuppa, H. Y., Jia, Labaciren, H. J., Li, G., Liguori, C., Liu, J., Liu, M. Y., Liu, H., Lu, L. L., Ma, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, Panareo, Marco, Perrone, Lorenzo, P., Pistilli, F., Ruggieri, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, H., Wang, C. Y., Wu, H. R., Wu, L., Xue, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhang, J., Zhao, Zhaxiciren, Zhaxisangzhu, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, G., Zizzi, P., Bernardini, Catalanotti, Sergio, A., D'Amone, I., De Mitri, DI GIROLAMO, Tristano, Iacovacci, Michele, G., Mancarella, G., Marsella, D., Martello, M., Panareo, and L., Perrone
Subjects: Physics, Radiation, Atmospheric pressure, Astrophysics::High Energy Astrophysical Phenomena, Settore FIS/01 - Fisica Sperimentale, Detector, Extensive air shower, Radon - natural radioactivity, Gamma ray, chemistry.chemical_element, Cosmic ray, Radon, Gamma-ray astronomy, Extensive air shower, Low energy cosmic instrumentation, Natural radioactivity, Radon, Nuclear physics, Air shower, chemistry, Low energy cosmic instrumentation, Natural radioactivity, Instrumentation, Radioactive decay, Physics::Atmospheric and Oceanic Physics
Abstract: The ARGO-YBJ experiment is an air shower detector for gamma ray astronomy and cosmic ray studies with an energy threshold of ∼500 GeV. Working in “single particle mode”, i.e. counting the single particles hitting the detector at fixed time intervals, ARGO-YBJ can monitor cosmic ray and gamma ray transients at energies of a few GeV. The single particle counting rate is modulated by the atmospheric pressure and temperature, and is affected by the local radioactivity from soil and air. Among the radioactive elements, radon gas is of particular importance since its concentration in air can vary significantly, according to environmental conditions. In this paper we evaluate the contribution of the radon daughter gamma ray emitters to the single particle counting rate measured by ARGO-YBJ. According to our analysis, the radon gas contribution is roughly 1–2%, producing a counting rate modulation of the same order of magnitude of the atmospheric effects.
Published: 2014

28. Cosmic ray physics with the ARGO-YBJ experiment

Author: B. Bartoli, X. J. Bi, C. Bleve, I. Bolognino, P. Branchini, A. Budano, A. K. Calabrese Melcarne, P. Camarri, Z. Cao, A. Cappa, R. Cardarelli, S. Catalanotti, C. Cattaneo, P. Celio, S. Z. Chen, T. L. Chen, Y. Chen, P. Creti, S. W. Cui, B. Z. Dai, G. D’Alì Staiti, Danzengluobu, M. Dattoli, B. D’Ettorre Piazzoli, T. Di Girolamo, X. H. Ding, G. Di Sciascio, C. F. Feng, Zhaoyang Feng, Zhenyong Feng, F. Galeazzi, P. Galeotti, E. Giroletti, Q. B. Gou, Y. Q. Guo, H. H. He, Haibing Huo, Hongbo Hue, Q. Huang, M. Iacovacci, R. Iuppa, I. James, H. Y. Jia, Labaciren, H. J. Li, J. Y. Li, X. X. Li, G. Liguori, C. Liu, C. Q. Liu, J. Liu, M. Y. Liu, H. Lu, X. H. Ma, S. M. Mari, S. Mastroianni, P. Montini, C. C. Ning, A. Pagliaro, B. Panico, P. Pistilli, X. B. Qu, E. Rossi, F. Ruggieri, P. Salvini, R. Santonico, P. R. Shen, X. D. Sheng, F. Shi, C. Stanescu, A. Surdo, Y. H. Tan, P. Vallania, S. Vernetto, C. Vigorito, B. Wang, H. Wang, C. Y. Wu, H. R. Wu, B. Xu, L. Xue, Y. X. Yan, Q. Y. Yang, X. C. Yang, Z. G. Yao, A. F. Yuan, M. Zha, H. M. Zhang, JilongZhang, JianliZhang, L. Zhang, P. Zhang, X. Y. Zhang, Y. Zhang, Zhaxiciren, Zhaxisangzhu, X. X. Zhou, F. R. Zhu, Q. Q. Zhu, G. Zizzi, BERNARDINI, Paolo, DE MITRI, Ivan, MANCARELLA, Giovanni, MARSELLA, GIOVANNI, MARTELLO, Daniele, PANAREO, Marco, PERRONE, Lorenzo, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, I., Bolognino, P., Branchini, A., Budano, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, A., Cappa, R., Cardarelli, S., Catalanotti, C., Cattaneo, P., Celio, S. Z., Chen, T. L., Chen, Y., Chen, P., Creti, S. W., Cui, B. Z., Dai, G., D’Alì Staiti, Danzengluobu, M., Dattoli, DE MITRI, Ivan, B., D’Ettorre Piazzoli, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, F., Galeazzi, P., Galeotti, E., Giroletti, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Huo, Hongbo, Hue, Q., Huang, M., Iacovacci, R., Iuppa, I., Jame, H. Y., Jia, Labaciren, H. J., Li, J. Y., Li, X. X., Li, G., Liguori, C., Liu, C. Q., Liu, J., Liu, M. Y., Liu, H., Lu, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, A., Pagliaro, Panareo, Marco, B., Panico, Perrone, Lorenzo, P., Pistilli, X. B., Qu, E., Rossi, F., Ruggieri, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, B., Wang, H., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, Y. X., Yan, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, Jilongzhang, Jianlizhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, Zhaxiciren, Zhaxisangzhu, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, and G., Zizzi
Subjects: Astroparticle physics, Physics, Physics and Astronomy (miscellaneous), Proton, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Cosmic ray, Cosmic Rays, Array Detector, Astrophysics, Air shower, Observatory, Gamma-ray burst, Heliosphere
Abstract: The main scientific goals of the ARGO-YBJ ex- periment are -ray astronomy with a few hundreds GeV en- ergy threshold and cosmic ray physics below and around the knee of the primary energy spectrum (10 12 10 16 eV), where the transition from direct to indirect measurement techniques takes place. The ARGO-YBJ experiment, located at the Cos- mic Ray Observatory of Yangbajing (Tibet, P.R. of China, 4 300 m a.s.l.), is an unconventional Extensive Air Shower ar- ray of about 6,700 m 2 of active area, the only one exploiting the full-coverage technique at very high altitude currently in operation. The detector space-time granularity, performance and location offer a unique chance to make a detailed study of the structure of cosmic ray showers, in particular of the hadronic component. In this work we will focus on the main experimental results concerning cosmic ray and hadronic in- teraction physics: primary cosmic ray energy spectrum, an- tiproton over proton ratio, anisotropy in the cosmic ray flux and proton-air cross-section. Moreover, the possible data analysis improvements based on the use of all detailed infor- mation on the shower front (curvature, time width, rise time, ..), as well as the extension of the investigable energy range, allowed by the analog RPC readout, will be pointed out. nique at very high altitude presently in data taking. Location and detector features make ARGO-YBJ capable of investi- gating a wide range of fundamental issues in Cosmic Ray and Astroparticle Physics at relatively low energy threshold: - very high energy -ray astronomy, with an energy thresh- old of a few hundreds GeV; - search for emission of gamma ray bursts in the full GeV - TeV energy range; - study of cosmic rays (spectrum, composition, p/p ra- tio measurement, shower space-time structure, ...) starting at TeV energies; - Sun and heliosphere physics above Eth 1 GeV. In following sections, after a brief description of the detec- tor and its performance, the main results achieved on several items of cosmic ray physics will be presented and discussed.
Published: 2011

29. The Yangbajing Super Complex Array Plan Based on the ARGO Carpet

Author: THE ARGO YBJ COLLABORATION G. Aielli a, b, C. Bacci c, d, B. Bartoli e, f, P. Bernardini g, h, X. J. Bi i, C. Bleve g, P. Branchini d, A. Budano d, S. Bussino c, A. K. Calabrese Melcarne x, P. Camarri a, Z. Cao i, A. Cappa j, k, R. Cardarelli b, S. Catalanotti f, e, C. Cattaneo l, P. Celio c, S. Z. Chen i, Y. Chen i, N. Cheng i, P. Creti h, S. W. Cuim, B. Z. Dai o, G. D’Alí Staiti n, p, Danzengluobu q, M. Dattoli j, k, r, I. De Mitri g, B. D’Ettorre Piazzoli f, M. De Vincenzi c, T. Di Girolamo f, X. H. Ding q, G. Di Sciascio b, C. F. Feng s, Zhaoyang Feng i, Zhenyong Feng t, F. Galeazzi d, P. Galeotti j, r, R. Gargana d, Q. B. Gou i, Y. Q. Guo i, H. H. He i, Haibing Huq, Hongbo Hui, Q. Huang t, M. Iacovacci f, R. Iuppa a, I. James c, H. Y. Jia t, Labaciren q, H. J. Li q, J. Y. Li s, X. X. Li i, B. Liberti b, G. Liguori l, u, C. Liu i, C. Q. Liu o, M. Y. Lium, J. Liu o, H. Lui, X. H. Mai, G. Mancarella g, c, d, G. Marsella h, v, D. Martello g, S. Mastroianni e, X. R. Meng q, P. Montini c, C. C. Ning q, A. Pagliaro n, w, M. Panareo h, L. Perrone h, P. Pistilli c, X. B. Qu s, E. Rossi e, F. Ruggieri d, L. Saggese f, P. Salvini l, R. Santonico a, P. R. Shen i, X. D. Sheng i, F. Shi i, C. Stanescu d, A. Surdo h, Y. H. Tan i, P. Vallania j, S. Vernetto j, C. Vigorito j, B. Wangi, H. Wang i, C. Y. Wui, H. R. Wui, B. Xut, L. Xues, Y. X. Yanm, Q. Y. Yang o, X. C. Yang o, A. F. Yuan q, M. Zha i, H. M. Zhang i, JiLong Zhang i, JianLi Zhang i, L. Zhang o, P. Zhang o, X. Y. Zhang s, Y. Zhang i, Zhaxisangzhu q, X. X. Zhou t, F. R. Zhu i, Q. Q. Zhu i, G. Zizzi g, MARI, Stefano Maria, THE ARGO YBJ COLLABORATION G., Aielli a, B, C., Bacci c, D, B., Bartoli e, F, P., Bernardini g, H, X. J., Bi i, C., Bleve g, P., Branchini d, A., Budano d, S., Bussino c, A. K., Calabrese Melcarne x, P., Camarri a, Z., Cao i, A., Cappa j, K, R., Cardarelli b, S., Catalanotti f, E, C., Cattaneo l, P., Celio c, S. Z., Chen i, Y., Chen i, N., Cheng i, P., Creti h, S. W., Cuim, B. Z., Dai o, G., D’Alí Staiti n, P, Danzengluobu, Q, M., Dattoli j, K, R, I., De Mitri g, B., D’Ettorre Piazzoli f, M., De Vincenzi c, T., Di Girolamo f, X. H., Ding q, G., Di Sciascio b, C. F., Feng, Zhaoyang Feng, I, Zhenyong Feng, T, F., Galeazzi d, P., Galeotti j, R, R., Gargana d, Q. B., Gou i, Y. Q., Guo i, H. H., He i, Haibing, Huq, Hongbo, Hui, Q., Huang t, M., Iacovacci f, R., Iuppa a, I., James c, H. Y., Jia t, Labaciren, Q, H. J., Li q, J. Y., Li, X. X., Li i, B., Liberti b, G., Liguori l, U, C., Liu i, C. Q., Liu o, M. Y., Lium, J., Liu o, H., Lui, X. H., Mai, G., Mancarella g, Mari, Stefano Maria, C, D, G., Marsella h, V, D., Martello g, S., Mastroianni e, X. R., Meng q, P., Montini c, C. C., Ning q, A., Pagliaro n, W, M., Panareo h, L., Perrone h, P., Pistilli c, X. B., Qu, E., Rossi e, F., Ruggieri d, L., Saggese f, P., Salvini l, R., Santonico a, P. R., Shen i, X. D., Sheng i, F., Shi i, C., Stanescu d, A., Surdo h, Y. H., Tan i, P., Vallania j, S., Vernetto j, C., Vigorito j, B., Wangi, H., Wang i, C. Y., Wui, H. R., Wui, B., Xut, L., Xue, Y. X., Yanm, Q. Y., Yang o, X. C., Yang o, A. F., Yuan q, M., Zha i, H. M., Zhang i, JiLong Zhang, I, JianLi Zhang, I, L., Zhang o, P., Zhang o, X. Y., Zhang, Y., Zhang i, Zhaxisangzhu, Q, X. X., Zhou t, F. R., Zhu i, Q. Q., Zhu i, and G., Zizzi g
Subjects: Physics, Nuclear and High Energy Physics, Proton, business.industry, Detector, Gamma ray, Phase (waves), Scintillator, Interference (wave propagation), Atomic and Molecular Physics, and Optics, Optics, business, Event (particle physics), Argo
Abstract: Following the completion of the 5700m 2 RPC carpet-like AS array at YangBaJing this year, a further plan based on the ARGO Carpet is raised. It characterizes with its high altitude site, its full-coverage detector array and the multi-parameter measurements. Apart from studies on TeV and sub-TeV energy range, UHE Gamma-ray sources and the Knee Physics will become its characteristic subjects. In the first phase of the plan, the Yangbajing Super Complex Array (YSCA) will include a 10 4 m 2 RPC Carpet, five indoor μ -detectors (∼170 m 2 each), four big outdoor μ -detectors (∼432 m 2 each) and a traditional field scintillation detector array surrounding the Carpet. Monte-Carlo study shows that, with such an array in YBJ (4300m a.s.l.), γ -ray induced air showers can be separated from proton induced air showers clearly using only the observed electron and μ data event by event. To assist the classification of UHE air showers induced by different primary nuclei groups without severe interference by Composition/Model Entanglement, a second phase plan having a Central Burst Detector Array (CBDA) and some pulse shape detectors is schemed.
Published: 2008

30. Preliminary results of the Moon shadow using ARGO-YBJ detector

Author: G. Aielli, C. Bacci, F. Barone, B. Bartoli, X. J. Bi, C. Bleve, P. Branchini, A. Budano, S. Bussino, A. K. Calabrese Melcarne, P. Camarri, Z. Cao, A. Cappa, R. Cardarelli, S. Catalanotti, C. Cattaneo, S. Cavaliere, P. Celio, S. Z. Chen, N. Cheng, P. Creti, S. W. Cui, G. Cusumano, B. Z. Dai, G. D’Alí Staiti, Danzengluobu, M. Dattoli, R. De Rosa, B. D’Ettorre Piazzoli, M. De Vincenzi, T. Di Girolamo, X. H. Ding, G. Di Sciascio, C. F. Feng, Zhaoyang Feng, Zhenyong Feng, C. Ferrigno, F. Galeazzi, P. Galeotti, X. Y. Gao, R. Gargana, F. Garufi, Q. B. Gou, H. H. He, Haibing Hu, Hongbo Hu, Q. Huang, M. Iacovacci, I. James, H. Y. Jia, Labaciren, H. J. Li, J. Y. Li, B. Liberti, G. Liguori, C. Q. Liu, J. Liu, H. Lu, S. M. Mari, S. Mastroianni, X. R. Meng, J. Mu, L. Nicastro, C. C. Ning, L. Palummo, P. Pistilli, X. B. Qu, E. Rossi, F. Ruggieri, L. Saggese, P. Salvini, R. Santonico, A. Segreto, P. R. Shen, X. D. Sheng, F. Shi, C. Stanescu, A. Surdo, Y. H. Tan, P. Vallania, S. Vernetto, C. Vigorito, H. Wang, Y. G. Wang, C. Y. Wu, H. R. Wu, B. Xu, L. Xue, H. T. Yang, Q. Y. Yang, X. C. Yang, G. C. Yu, A. F. Yuan, M. Zha, H. M. Zhang, J. L. Zhang, L. Zhang, P. Zhang, X. Y. Zhang, Y. Zhang, Zhaxisangzhu, X. X. Zhou, F. R. Zhu, Q. Q. Zhu, G. Zizzi, BERNARDINI, Paolo, DE MITRI, Ivan, MANCARELLA, Giovanni, MARSELLA, GIOVANNI, MARTELLO, Daniele, PANAREO, Marco, PERRONE, Lorenzo, G., Aielli, C., Bacci, F., Barone, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, P., Branchini, A., Budano, S., Bussino, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, A., Cappa, R., Cardarelli, S., Catalanotti, C., Cattaneo, S., Cavaliere, P., Celio, S. Z., Chen, N., Cheng, P., Creti, S. W., Cui, G., Cusumano, B. Z., Dai, G., D’Alí Staiti, Danzengluobu, M., Dattoli, DE MITRI, Ivan, R., De Rosa, B., D’Ettorre Piazzoli, M., De Vincenzi, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, C., Ferrigno, F., Galeazzi, P., Galeotti, X. Y., Gao, R., Gargana, F., Garufi, Q. B., Gou, H. H., He, Haibing, Hu, Hongbo, Hu, Q., Huang, M., Iacovacci, I., Jame, H. Y., Jia, Labaciren, H. J., Li, J. Y., Li, B., Liberti, G., Liguori, C. Q., Liu, J., Liu, H., Lu, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, X. R., Meng, J., Mu, L., Nicastro, C. C., Ning, L., Palummo, Panareo, Marco, Perrone, Lorenzo, P., Pistilli, X. B., Qu, E., Rossi, F., Ruggieri, L., Saggese, P., Salvini, R., Santonico, A., Segreto, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, H., Wang, Y. G., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, H. T., Yang, Q. Y., Yang, X. C., Yang, G. C., Yu, A. F., Yuan, M., Zha, H. M., Zhang, J. L., Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, Zhaxisangzhu, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, G., Zizzi, Aielli, G, Bacci, C, Bartoli, B, Bernardini, P, Bi, Xj, Bleve, C, Branchini, P, Budano, A, Bussino, Severino Angelo Maria, Calabrese Melcarne, Ak, Camarri, P, Cao, Z, Cappa, A, Cardarelli, R, Catalanotti, S, Cattaneo, C, Celio, P, Chen, Sz, Chen, Tl, Chen, Y, Cheng, N, Creti, P, Cui, Sw, Dai, Bz, D'Ali Staiti, G, Dattoli, M, De Mitri, I, D'Ettorre Piazzoli, B, De Vincenzi, M, Di Girolamo, T, Ding, Xh, Di Sciascio, G, Feng, Cf, Feng Zhao, Yang, Feng Zhen, Yong, Galeazzi, F, Galeotti, P, Gargana, R, Gou, Qb, Guo, Yq, He, Hh, Hu, Haibing, Hu Hong, Bo, Huang, Q, Iacovacci, M, Iuppa, R, James, I, Jia, Hy, Li, Hj, Li, Jy, Li, Xx, Liberti, B, Liguori, G, Liu, C, Liu, Cq, Liu, My, Liu, J, Lu, H, Ma, Xh, Mancarella, G, Mari, Stefano Maria, Marsella, G, Martello, D, Mastroianni, S, Meng, Xr, Montini, P, Ning, Cc, Pagliaro, A, Panareo, M, Perrone, L, Pistilli, P, Qu, Xb, Rossi, E, Ruggieri, F, Saggese, L, Salvini, P, Santonico, R, Shen, Pr, Sheng, Xd, Shi, F, Stanescu, C, Surdo, A, Tan, Yh, Vallania, P, Vernetto, S, Vigorito, C, Wang, B, Wang, H, Wu, Cy, Wu, Hr, Xu, B, Xue, L, Yan, Yx, Yang, Qy, Yang, Xc, Yuan, Af, Zha, M, Zhang, Hm, Zhang Ji, Long, Zhang Jian, Li, Zhang, L, Zhang, P, Zhang, Xy, Zhang, Y, Zhou, Xx, Zhu, Fr, Zhu, Qq, and Zizzi, G.
Subjects: Physics, Nuclear and High Energy Physics, Detector, Moon shadow, Astronomy, Cosmic ray, Full coverage, Resistive Plate Chamber, Atomic and Molecular Physics, and Optics, Argo-Ybj, Air shower, Extended air shower, Shadow, Angular resolution, Argo
Abstract: ARGO-YBJ is a “full coverage” air shower detector consisting of Resistive Plate Chambers(RPCs) at the Yangbajing High Altitude Cosmic Ray Laboratory (Tibet, China) at 4300 m a.s.l. (lat=30.11° N, long=90.53° E). Using the data collected with a carpet of RPCs (1900 m 2 , about 1/3 of the whole ARGO-YBJ detector), the cosmic ray shadowing effect due to the Moon was studied. The 50% angular resolution is found to be ∼1.2° with the Chess-board method and the Moon shadow with a significance of 4.9 σ is found displaced by 0.7° westward and 0.5° northward with respect to the expected position by the equi-zenith angle Method.
Published: 2008

31. Extinction coefficients of surface atmospheric aerosol above LHAASO *

Author: Huan-Yu Jia, Q. H. Chen, Y. He, F. R. Zhu, Min Huang, Wen-Xuan Pi, Yong Zhang, and Ning Xie
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Mie scattering, Astronomy and Astrophysics, Molar absorptivity, Atmospheric sciences, 01 natural sciences, Wind speed, Aerosol, Wavelength, Air shower, Lidar, Extinction (optical mineralogy), 0103 physical sciences, 010306 general physics, Instrumentation
Abstract: We investigate the extinction coefficients of the surface atmospheric aerosol over the Large High Altitude Air Shower Observatory (LHAASO), located at the Haizi Mountain, Daocheng County, China. To this end, we utilize the Longtin model, Mie scattering theory, and experimental data obtained by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO). Our theoretical calculations show that the total extinction coefficients of the atmospheric aerosol at the wavelength of 200–500 nm are inversely proportional to the laser wavelength, and influenced by the wind speed. From July 2015 to October 2016, the extinction coefficient of the surface atmospheric aerosols at 532 nm wavelength reached 0.04 km−1 with no wind, while it increased to 0.1 km−1 with gusts. In this period, the extinction coefficients of the surface atmospheric aerosol at 532 nm wavelength, obtained by the CALIPSO, change from 0.01 to 0.07 km−1, which is less than the values obtained the theoretical calculation and larger than the average of Tibetan Plateau in 2006−2016. These calculations and experimental evidence provide important arguments to the model of atmospheric aerosol to be applied in the calibration of LHAASO. Our results suggest that the extinction coefficients over LHAASO require further study, including research on the size distribution, shape, concentration of aerosols particles, wind dependence, relative humidity dependence, etc.
Published: 2019

32. STUDY OF THE DIFFUSE GAMMA-RAY EMISSION FROM THE GALACTIC PLANE WITH ARGO-YBJ

Author: Q. Q. Zhu, Labaciren, Zhengguo Cao, P. Bernardini, J. K. K. Liu, X. X. Zhou, C. Y. Wu, J. Zhao, Y. J. Zhang, R. Santonico, H. H. He, Zhenyong Feng, P. R. Shen, F. Shi, C. Q. Liu, Q. B. Gou, F. R. Zhu, P. Creti, C. C. Ning, X. C. Yang, Haifeng Li, H. Lu, I. De Mitri, A. D'Amone, P. Vallania, S. M. Mari, T. Di Girolamo, Danzengluobu, R. Cardarelli, A. F. Yuan, M. Panareo, Minghui Liu, B. D'Ettorre Piazzoli, Y. H. Tan, M. Zha, Lanqing Ma, X. J. Bi, L. Xue, L. Zhang, T. L. Chen, S. Vernetto, Zhaxiciren, A. Surdo, R. Iuppa, G. Zizzi, C. Vigorito, Zhaxisangzhu, P. Salvini, Q. Y. Yang, S. Z. Chen, G. Marsella, B. Bartoli, G. Liguori, M. Iacovacci, S. Catalanotti, B. Z. Dai, Zhaoyang Feng, Paolo Camarri, P. Montini, X. H. Ma, L. Perrone, G. Di Sciascio, X. Y. Zhang, A. Budano, Z. G. Yao, Haibing Hu, Xiangdong Sheng, S. Mastroianni, D. Martello, P. Pistilli, H. M. Zhang, H. R. Wu, Hongbo Hu, Yicheng Guo, H. Wang, Cunfeng Feng, F. Ruggieri, H. Y. Jia, S. W. Cui, G. Mancarella, P. Branchini, Mari, Stefano Maria, The ARGO YBJ, Collaboration, ITA, Bartoli, Bruno, Bernardini, P., Bi, X. J., Branchini, P., Budano, A., Camarri, P., Cao, Z., Cardarelli, R., Catalanotti, Sergio, Chen, S. Z., Chen, T. L., Creti, P., Cui, S. W., Dai, B. Z., D’Amone, A., Danzengluobu, Null, De Mitri, I., D'ETTORRE PIAZZOLI, Benedetto, DI GIROLAMO, Tristano, Sciascio, G. Di, Feng, C. F., Feng, Zhaoyang, Feng, Zhenyong, Gou, Q. B., Guo, Y. Q., He, H. H., Hu, Haibing, Hu, Hongbo, Iacovacci, Michele, Iuppa, R., Jia, H. Y., Labaciren, Null, Li, H. J., Liguori, G., Liu, C., Liu, J., Liu, M. Y., Lu, H., Ma, L. L., Ma, X. H., Mancarella, G., Mari, S. M., Marsella, G., Martello, D., Mastroianni, S., Montini, P., Ning, C. C., Panareo, M., Perrone, L., Pistilli, P., Ruggieri, F., Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, H., Wu, C. Y., Wu, H. R., Xue, L., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M., Zhang, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhao, J., Zhaxiciren, Null, Zhaxisangzhu, Null, Zhou, X. X., Zhu, F. R., Zhu, Q. Q., Zizzi, G., B., Bartoli, Bernardini, Paolo, X. J., Bi, P., Branchini, A., Budano, P., Camarri, Z., Cao, R., Cardarelli, S., Catalanotti, S. Z., Chen, T. L., Chen, P., Creti, S. W., Cui, B. Z., Dai, D'Amone, Antonio, Danzengluobu, DE MITRI, Ivan, B., D’Ettorre Piazzoli, T., Di Girolamo, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Hu, Hongbo, Hu, M., Iacovacci, R., Iuppa, H. Y., Jia, Labaciren, H. J., Li, G., Liguori, C., Liu, J., Liu, M. Y., Liu, H., Lu, L. L., Ma, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, Panareo, Marco, Perrone, Lorenzo, P., Pistilli, F., Ruggieri, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, H., Wang, C. Y., Wu, H. R., Wu, L., Xue, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhang, J., Zhao, Zhaxiciren, Zhaxisangzhu, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, and G., Zizzi
Subjects: Astrophysics::High Energy Astrophysical Phenomena, observational [methods], Flux, FOS: Physical sciences, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, disk, methods: observational [cosmic rays, diffuse radiation, Galaxy], Galaxy: disk, High Energy Physics - Phenomenology (hep-ph), cosmic rays, Disc, Instrumentation and Methods for Astrophysics (astro-ph.IM), cosmic ray, Astrophysics::Galaxy Astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Settore FIS/01 - Fisica Sperimentale, Gamma ray, Astronomy and Astrophysics, Galactic plane, Galaxy, diffuse radiation, High Energy Physics - Phenomenology, Space and Planetary Science, Milagro, methods: observational, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, disk [Galaxy], Fermi Gamma-ray Space Telescope
Abstract: The events recorded by ARGO-YBJ in more than five years of data collection have been analyzed to determine the diffuse gamma-ray emission in the Galactic plane at Galactic longitudes 25{\deg} < l < 100{\deg} and Galactic latitudes . The energy range covered by this analysis, from ~350 GeV to ~2 TeV, allows the connection of the region explored by Fermi with the multi-TeV measurements carried out by Milagro. Our analysis has been focused on two selected regions of the Galactic plane, i.e., 40{\deg} < l < 100{\deg} and 65{\deg} < l < 85{\deg} (the Cygnus region), where Milagro observed an excess with respect to the predictions of current models. Great care has been taken in order to mask the most intense gamma-ray sources, including the TeV counterpart of the Cygnus cocoon recently identified by ARGO-YBJ, and to remove residual contributions. The ARGO-YBJ results do not show any excess at sub-TeV energies corresponding to the excess found by Milagro, and are consistent with the predictions of the Fermi model for the diffuse Galactic emission. From the measured energy distribution we derive spectral indices and the differential flux at 1 TeV of the diffuse gamma-ray emission in the sky regions investigated., Comment: 11 pages, 6 figures, published in APJ
Published: 2015

33. Calibration of the RPC charge readout in the ARGO-YBJ experiment with the iso-gradient method

Author: Labaciren, Zhenyong Feng, X. J. Bi, I. De Mitri, B. D Ettorre Piazzoli, Carlo Vigorito, T. L. Chen, B. Bartoli, S. Z. Chen, Haibing Hu, Piero Vallania, G. Di Sciascio, R. Santonico, Y. H. Tan, S. W. Cui, Y. Zhang, D. Martello, Q. Y. Yang, X. Y. Zhang, H. H. He, S. M. Mari, L. Xue, G. Zizzi, Zhaxiciren, Minghui Liu, L. L. Ma, H. Y. Jia, Z. G. Yao, P. Pistilli, H. M. Zhang, X. X. Zhou, F. R. Zhu, A. D Amone, M. Iacovacci, M. Zha, P. Creti, A. F. Yuan, T. Di Girolamo, Danzengluobu, Haifeng Li, H. W. Wang, J. B. Zhao, P. Salvini, Zihuang Cao, Q. Q. Zhu, Paolo Montini, H. R. Wu, R. Iuppa, A. Budano, G. Mancarella, Zhaxisangzhu, C. Y. Wu, S. Vernetto, Hongbo Hu, Fudong Shi, A. Surdo, S. Mastroianni, Yicheng Guo, Pengnian Shen, L. Perrone, S. Catalanotti, B. Z. Dai, F. Ruggieri, J. K. K. Liu, Cunfeng Feng, X. C. Yang, Q. B. Gou, P. Branchini, H. Lu, X. H. Ma, Paolo Camarri, X. D. Sheng, Paolo Bernardini, Chang-Chun Ning, Zhaoyang Feng, L. Zhang, M. Panareo, G. Liguori, R. Cardarelli, C. X. Liu, G. Marsella, B., Bartoli, Bernardini, Paolo, X. J., Bi, P., Branchini, A., Budano, P., Camarri, Z., Cao, R., Cardarelli, S., Catalanotti, S. Z., Chen, T. L., Chen, P., Creti, S. W., Cui, B. Z., Dai, D'Amone, Antonio, Danzengluobu, DE MITRI, Ivan, B., D׳Ettorre Piazzoli, T., Di Girolamo, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Hu, Hongbo, Hu, M., Iacovacci, R., Iuppa, H. Y., Jia, Labaciren, H. J., Li, G., Liguori, C., Liu, J., Liu, M. Y., Liu, H., Lu, L. L., Ma, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, Panareo, Marco, Perrone, Lorenzo, P., Pistilli, F., Ruggieri, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, H., Wang, C. Y., Wu, H. R., Wu, L., Xue, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhang, J., Zhao, Zhaxiciren, Zhaxisangzhu, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, G., Zizzi, Bartoli, B., Bernardini, P., Bi, X. J., Branchini, P., Budano, A., Camarri, P., Cao, Z., Cardarelli, R., Catalanotti, S., Chen, S. Z., Chen, T. L., Creti, P., Cui, S. W., Dai, B. Z., Damone, A., Danzengluobu, Null, De Mitri, I., Dettorre Piazzoli, B., Di Girolamo, T., Di Sciascio, G., Feng, C. F., Feng, Zhaoyang, Feng, Zhenyong, Gou, Q. B., Guo, Y. Q., He, H. H., Hu, Haibing, Hu, Hongbo, Iacovacci, M., Iuppa, R., Jia, H. Y., Labaciren, Null, Li, H. J., Liguori, G., Liu, C., Liu, J., Liu, M. Y., Lu, H., Ma, L. L., Ma, X. H., Mancarella, G., Mari, S. M., Marsella, G., Martello, D., Mastroianni, S., Montini, P., Ning, C. C., Panareo, M., Perrone, L., Pistilli, P., Ruggieri, F., Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, H., Wu, C. Y., Wu, H. R., Xue, L., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M., Zhang, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhao, J., Zhaxiciren, Null, Zhaxisangzhu, Null, Zhou, X. X., Zhu, F. R., Zhu, Q. Q., Zizzi, G., Mari, Stefano Maria, and The ARGO YBJ, Collaboration
Subjects: Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, RPC Response difference Calibration, law.invention, Telescope, Optics, law, Calibration, Instrumentation, Nuclear and High Energy Physic, Physics, Resistive touchscreen, Scintillation, Muon, Iso-gradient method, business.industry, Detector, Settore FIS/01 - Fisica Sperimentale, Astrophysics::Instrumentation and Methods for Astrophysics, Charge (physics), Response difference, RPC, High Energy Physics::Experiment, business, Gradient method
Abstract: The ARGO-YBJ experiment is a full coverage array of Resistive Plate Chambers (RPCs) with an active area of 5800 m 2 . In order to eliminate the response difference of the charge readout from the RPCs, a calibration procedure is carried out with the iso-gradient method. This method also allows the extension of the absolute calibration with the muon telescope including scintillation detectors to all the RPCs in the array. The overall systematic uncertainty in measurements o10.7%. In general, the method gives results consistent with those from a totally different approach also used in the experiment. The ARGO-YBJ experiment is a full coverage array of Resistive Plate Chambers (RPCs) with an active area of 5800 m2. In order to eliminate the response difference of the charge readout from the RPCs, a calibration procedure is carried out with the iso-gradient method. This method also allows the extension of the absolute calibration with the muon telescope including scintillation detectors to all the RPCs in the array. The overall systematic uncertainty in measurements of the number of particles by the RPCs is 10.7%. In general, the method gives results consistent with those from a totally different approach also used in the experiment.
Published: 2015

34. Constraint on the velocity dependent dark matter annihilation cross section from Fermi-LAT observations of dwarf galaxies

Author: F. R. Zhu, Huan-Yu Jia, Xiao-Jun Bi, Y. X. Zhao, and Peng-Fei Yin
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Particle physics, Annihilation, 010308 nuclear & particles physics, Milky Way, Dark matter, FOS: Physical sciences, Velocity dispersion, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Galaxy, Positron, 0103 physical sciences, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Fermi Gamma-ray Space Telescope, Dwarf galaxy
Abstract: The $\ensuremath{\gamma}$-ray observation of dwarf spheroidal satellites (dSph's) is an ideal approach for probing the dark matter (DM) annihilation signature. The latest Fermi-LAT dSph searches have set stringent constraints on the velocity independent annihilation cross section in the small DM mass range, which gives very strong constraints on the scenario to explain the AMS-02 positron excess by DM annihilation. However, the dSph constraints would change in the velocity dependent annihilation scenarios, because the velocity dispersion in the dSph's varies from that in the Milky Way. In this work, we use a likelihood map method to set constraints on the velocity dependent annihilation cross section from the Fermi-LAT observation of six dSph's. We consider three typical forms of the annihilation cross section, i.e. p-wave annihilation, Sommerfeld enhancement, and Breit-Wigner resonance. For the p-wave annihilation and Sommerfeld enhancement, the dSph limits would become much weaker and stronger compared with those for the velocity independent annihilation, respectively. For the Breit-Wigner annihilation, the dSph limits would vary depending on the model parameters. We show that the scenario to explain the AMS-02 positron excess by DM annihilation is still viable in the velocity dependent cases.
Published: 2016

35. Detection of thermal neutrons with the PRISMA-YBJ array in extensive air showers selected by the ARGO-YBJ experiment

Author: M. Zha, Labaciren, C. C. Ning, O. B. Shchegolev, L. Zhang, T. L. Chen, C. Vigorito, Z. Y. Cai, Zhenyong Feng, P. Bernardini, P. Salvini, Hm Zhang, C. Y. Wu, G. Marsella, C. Q. Liu, Q. B. Gou, V. Volchenko, L. L. Ma, P. Vallania, Zhengguo Cao, R. Santonico, H. H. He, H. Lu, G. Mancarella, H. Wang, Danzengluobu, J. K. K. Liu, B. D'Ettorre Piazzoli, A. D'Amone, Q. Q. Zhu, A. F. Yuan, F. Shi, X. W. Guo, S. M. Mari, P. R. Shen, X. C. Yang, X. X. Zhou, T. Di Girolamo, L. Xue, V. V. Alekseenko, Yu. V. Stenkin, Zhaxiciren, Y. H. Tan, Zhaxisangzhu, Hongbo Hu, V. Aynutdinov, Cunfeng Feng, S. W. Cui, V.I. Stepanov, Yicheng Guo, X. J. Bi, Ye Liu, S. Vernetto, Q. Y. Yang, S. Z. Chen, F. R. Zhu, S. Mastroianni, H. Y. Jia, H. J. Li, H. R. Wu, P. Montini, X. H. Ma, V. Rulev, Minghui Liu, A. Surdo, G. Di Sciascio, Zhaoyang Feng, X. Y. Zhang, Xiangdong Sheng, J. Zhao, S. Catalanotti, B. Z. Dai, Y. J. Zhang, R. Iuppa, B. Bartoli, I. De Mitri, Haibing Hu, Z. G. Yao, L. Perrone, P. Pistilli, H. M. Zhang, M. Iacovacci, Bartoli, B., Bernardini, P., Bi, X. J., Cao, Z., Catalanotti, S., Chen, S. Z., Chen, T. L., Cui, S. W., Dai, B. Z., D’Amone, A., Danzengluobu, Null, De Mitri, I., D’Ettorre Piazzoli, B., Di Girolamo, T., Di Sciascio, G., Feng, C. F., Feng, Zhaoyang, Feng, Zhenyong, Gou, Q. B., Guo, Y. Q., He, H. H., Hu, Haibing, Hu, Hongbo, Iacovacci, M., Iuppa, R., Jia, H. Y., Labaciren, Null, Li, H. J., Liu, C., Liu, J., Liu, M. Y., Lu, H., Ma, L. L., Ma, X. H., Mancarella, G., Mari, Stefano Maria, Marsella, G., Mastroianni, S., Montini, Paolo, Ning, C. C., Perrone, L., Pistilli, Pio, Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, H., Wu, C. Y., Wu, H. R., Xue, L., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M., Zhang, H. M., Zhang, L., Zhang, X. Y., Zhang, Y., Zhao, J., Zhaxiciren, Null, Zhaxisangzhu, Null, Zhou, X. X., Zhu, F. R., Zhu, Q. Q., Stenkin, Y. u. V., Alekseenko, V. V., Aynutdinov, V., Cai, Z. Y., Guo, X. W., Liu, Y., Rulev, V., Shchegolev, O. B., Stepanov, V., Volchenko, V., Zhang, H., Bartoli, B, Bernardini, Paolo, Bi, Xj, Cao, Z, Catalanotti, S, Chen, Sz, Chen, Tl, Cui, Sw, Dai, Bz, D'Amone, Antonio, Danzengluobu, DE MITRI, Ivan, Piazzoli, Bd, Di Girolamo, T, Di Sciascio, G, Feng, Cf, Feng, Zy, Gou, Qb, Guo, Yq, He, Hh, Hu, H, Iacovacci, M, Iuppa, R, Jia, Hy, Labaciren, Li, Hj, Liu, C, Liu, J, Liu, My, Lu, H, Ma, Ll, Ma, Xh, Mancarella, Giovanni, Mari, Sm, Marsella, Giovanni, Mastroianni, S, Montini, P, Ning, Cc, Perrone, Lorenzo, Pistilli, P, Salvini, P, Santonico, R, Shen, Pr, Sheng, Xd, Shi, F, Surdo, A, Tan, Yh, Vallania, P, Vernetto, S, Vigorito, C, Wang, H, Wu, Cy, Wu, Hr, Xue, L, Yang, Qy, Yang, Xc, Yao, Zg, Yuan, Af, Zha, M, Zhang, Hm, Zhang, L, Zhang, Xy, Zhang, Y, Zhao, J, Zhaxiciren, Zhaxisangzhu, Zhou, Xx, Zhu, Fr, Zhu, Qq, Stenkin, Yv, Alekseenko, Vv, Aynutdinov, V, Cai, Zy, Guo, Xw, Liu, Y, Rulev, V, Shchegolev, Ob, Stepanov, V, Volchenko, V, Zhang, H[ 7 ] . . . Less, Bartoli, Bruno, Catalanotti, Sergio, D'ETTORRE PIAZZOLI, Benedetto, DI GIROLAMO, Tristano, Iacovacci, Michele, Mari, S. M., Montini, P., and Pistilli, P.
Subjects: Physics - Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Extensive air shower, FOS: Physical sciences, Cosmic ray, 01 natural sciences, Nuclear physics, EN-detector, Hadronic component, RPC, Thermal neutron, Astronomy and Astrophysics, Observatory, Coincident, 0103 physical sciences, 010306 general physics, Cosmic-ray observatory, Instrumentation and Methods for Astrophysics (astro-ph.IM), High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Calorimeter (particle physics), 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Instrumentation and Detectors (physics.ins-det), Neutron temperature, Air shower, High Energy Physics::Experiment, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on a measurement of thermal neutrons, generated by the hadronic component of extensive air showers (EAS), by means of a small array of EN-detectors developed for the PRISMA project (PRImary Spectrum Measurement Array), novel devices based on a compound alloy of ZnS(Ag) and $^{6}$LiF. This array has been operated within the ARGO-YBJ experiment at the high altitude Cosmic Ray Observatory in Yangbajing (Tibet, 4300 m a.s.l.). Due to the tight correlation between the air shower hadrons and thermal neutrons, this technique can be envisaged as a simple way to estimate the number of high energy hadrons in EAS. Coincident events generated by primary cosmic rays of energies greater than 100 TeV have been selected and analyzed. The EN-detectors have been used to record simultaneously thermal neutrons and the air shower electromagnetic component. The density distributions of both components and the total number of thermal neutrons have been measured. The correlation of these data with the measurements carried out by ARGO-YBJ confirms the excellent performance of the EN-detector., 35 pages, 16 figures
Published: 2016

36. Short-Term Periodicity in Solar Mean Magnetic Field during Activity Maximum and Minimum Periods

Author: N. Ye, H. Y. Jia, F. R. Zhu, and X. M. Zhou
Subjects: Physics, Solar minimum, Solar observatory, Meteorology, Space and Planetary Science, Activity cycle, Astronomy and Astrophysics, Maxima, Atmospheric sciences, Term (time), Magnetic field
Abstract: The short-term periodicity in the solar mean magnetic field (SMMF) observed at the Wilcox Solar Observatory during the last four activity cycles is investigated by using Lomb–Scargle periodograms. Our results show that the SMMF has main periods of about 27, 13.5, and 9 days in both the maximum and minimum years of each activity cycle. The SMMF has the most dominant period of about 27 days during the activity maxima. However, during the activity minimum years the 13.5-day periodicity is the most significant, except for the minimum of 1984 – 1986. These results indicate that the distribution of active regions in the activity maximum years is quite different from that in the minimum years.
Published: 2012

37. Search for gamma ray bursts with the ARGO-YBJ detector in scaler mode

Author: THE ARGO YBJ C.O.L.L.A.B.O.R.A.T.I.O.N.G. Aielli a, b, C. Bacci c, d, B. Bartoli e, f, P. Bernardini g, h, X. J. Bi i, C. Bleve g, P. Branchini d, A. Budano d, S. Bussino c, A. K. Calabrese Melcarne x, P. Camarri a, Z. Cao i, A. Cappa j, k, R. Cardarelli b, S. Catalanotti f, e, C. Cattaneo l, P. Celio c, S. Z. Chen i, Y. Chen i, N. Cheng i, P. Creti h, S. W. Cuim, B. Z. Dai o, G. D’Alí Staiti n, p, Danzengluobu q, M. Dattoli j, k, r, I. De Mitri g, B. D’Ettorre Piazzoli f, M. DeVincenzi c, T. Di Girolamo f, X. H. Ding q, G. Di Sciascio b, C. F. Feng s, ZhaoyangFeng i, Zhenyong Feng t, F. Galeazzi d, P. Galeotti j, r, R. Gargana d, Q. B. Gou i, Y. Q. Guo i, H. H. He i, Haibing Huq, Hongbo Hui, Q. Huang t, M. Iacovacci f, R. Iuppa a, I. James c, H. Y. Jia t, Labaciren q, H. J. Li q, J. Y. Li s, X. X. Li i, B. Liberti b, G. Liguori l, u, C. Liu i, C. Q. Liu o, M. Y. Lium, J. Liu o, H. Lui, X. H. Mai, G. Mancarellag, c, d, G. Marsella h, v, D. Martello g, S. Mastroianni e, X. R. Meng q, P. Montini c, C. C. Ning q, A. Pagliaro n, w, M. Panareo h, L. Perrone h, P. Pistilli c, X. B. Qu s, E. Rossi e, F. Ruggieri d, L. Saggese f, P. Salvini l, R. Santonico a, P. R. Shen i, X. D. Sheng i, F. Shi i, C. Stanescu d, A. Surdo h, Y. H. Tan i, P. Vallania j, S. Vernetto j, C. Vigorito j, B. Wangi, H. Wang i, C. Y. Wui, H. R. Wui, B. Xut, L. Xues, Y. X. Yanm, Q. Y. Yang o, X. C. Yang o, A. F. Yuan q, M. Zha i, H. M. Zhang i, JiLong Zhang i, JianLi Zhang i, L. Zhang o, P. Zhang o, X. Y. Zhang s, Y. Zhang i, Zhaxisangzhu q, X. X. Zhou t, F. R. Zhu i, Q. Q. Zhu i, G. Zizzi g, MARI, Stefano Maria, Aielli, G, Bacci, C, Bartoli, B, Bernardini, P, Bi, Xj, Bleve, C, Branchini, P, Budano, A, Bussino, Severino Angelo Maria, Calabrese Melcarne, Ak, Camarri, P, Cao, Z, Cappa, A, Cardarelli, R, Catalanotti, S, Cattaneo, C, Celio, P, Chen, Sz, Chen, Tl, Chen, Y, Cheng, N, Creti, P, Cui, Sw, Dai, Bz, D'Ali Staiti, G, Danzengluobu, Dattoli, M, De Mitri, I, D'Ettorre Piazzoli, B, De Vincenzi, M, Di Girolamo, T, Ding, Xh, Di Sciascio, G, Feng, Cf, Feng Zhao, Yang, Feng Zhen, Yong, Galeazzi, F, Galeotti, P, Gargana, R, Gou, Qb, Guo, Yq, He, Hh, Hu, Haibing, Hu Hong, Bo, Huang, Q, Iacovacci, M, Iuppa, R, James, I, Jia, Hy, Labaciren, Li, Hj, Li, Jy, Li, Xx, Liberti, B, Liguori, G, Liu, C, Liu, Cq, Liu, My, Liu, J, Lu, H, Ma, Xh, Mancarella, G, Mari, Stefano Maria, Marsella, G, Martello, D, Mastroianni, S, Meng, Xr, Montini, P, Ning, Cc, Pagliaro, A, Panareo, M, Perrone, L, Pistilli, P, Qu, Xb, Rossi, E, Ruggieri, F, Saggese, L, Salvini, P, Santonico, R, Shen, Pr, Sheng, Xd, Shi, F, Stanescu, C, Surdo, A, Tan, Yh, Vallania, P, Vernetto, S, Vigorito, C, Wang, B, Wang, H, Wu, Cy, Wu, Hr, Xu, B, Xue, L, Yan, Yx, Yang, Qy, Yang, Xc, Yuan, Af, Zha, M, Zhang, Hm, Zhang Ji, Long, Zhang Jian, Li, Zhang, L, Zhang, P, Zhang, Xy, Zhang, Y, Zhaxisangzhu, Zhou, Xx, Zhu, Fr, Zhu, Qq, Zizzi, G., G., Aielli, C., Bacci, F., Barone, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, P., Branchini, A., Budano, S., Bussino, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, A., Cappa, R., Cardarelli, S., Catalanotti, C., Cattaneo, S., Cavaliere, P., Celio, S. Z., Chen, N., Cheng, P., Creti, S. W., Cui, G., Cusumano, B. Z., Dai, G., D’Alí Staiti, M., Dattoli, DE MITRI, Ivan, R., De Rosa, B., D’Ettorre Piazzoli, M., De Vincenzi, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, C., Ferrigno, F., Galeazzi, P., Galeotti, X. Y., Gao, R., Gargana, F., Garufi, Q. B., Gou, H. H., He, Haibing, Hu, Hongbo, Hu, Q., Huang, M., Iacovacci, I., Jame, H. Y., Jia, H. J., Li, J. Y., Li, B., Liberti, G., Liguori, C. Q., Liu, J., Liu, H., Lu, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, X. R., Meng, J., Mu, L., Nicastro, C. C., Ning, L., Palummo, Panareo, Marco, Perrone, Lorenzo, P., Pistilli, X. B., Qu, E., Rossi, F., Ruggieri, L., Saggese, P., Salvini, R., Santonico, A., Segreto, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, H., Wang, Y. G., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, H. T., Yang, Q. Y., Yang, X. C., Yang, G. C., Yu, A. F., Yuan, M., Zha, H. M., Zhang, J. L., Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, G., Zizzi, Aielli a, THE ARGO YBJ C. O. L. L. A. B. O. R. A. T. I. O. N. G., B, C., Bacci c, D, B., Bartoli e, F, P., Bernardini g, H, X. J., Bi i, C., Bleve g, P., Branchini d, A., Budano d, S., Bussino c, A. K., Calabrese Melcarne x, P., Camarri a, Z., Cao i, A., Cappa j, K, R., Cardarelli b, S., Catalanotti f, E, C., Cattaneo l, P., Celio c, S. Z., Chen i, Y., Chen i, N., Cheng i, P., Creti h, S. W., Cuim, B. Z., Dai o, G., D’Alí Staiti n, P, Danzengluobu, Q, M., Dattoli j, K, R, I., De Mitri g, B., D’Ettorre Piazzoli f, M., DeVincenzi c, T., Di Girolamo f, X. H., Ding q, G., Di Sciascio b, Zhaoyangfeng, I, Zhenyong Feng, T, F., Galeazzi d, P., Galeotti j, R, R., Gargana d, Q. B., Gou i, Y. Q., Guo i, H. H., He i, Haibing, Huq, Hongbo, Hui, Q., Huang t, M., Iacovacci f, R., Iuppa a, I., James c, H. Y., Jia t, Labaciren, Q, H. J., Li q, X. X., Li i, B., Liberti b, G., Liguori l, U, C., Liu i, C. Q., Liu o, M. Y., Lium, J., Liu o, H., Lui, X. H., Mai, G., Mancarellag, C, D, G., Marsella h, V, D., Martello g, S., Mastroianni e, X. R., Meng q, P., Montini c, C. C., Ning q, A., Pagliaro n, W, M., Panareo h, L., Perrone h, P., Pistilli c, E., Rossi e, F., Ruggieri d, L., Saggese f, P., Salvini l, R., Santonico a, P. R., Shen i, X. D., Sheng i, F., Shi i, C., Stanescu d, A., Surdo h, Y. H., Tan i, P., Vallania j, S., Vernetto j, C., Vigorito j, B., Wangi, H., Wang i, C. Y., Wui, H. R., Wui, B., Xut, Y. X., Yanm, Q. Y., Yang o, X. C., Yang o, A. F., Yuan q, M., Zha i, H. M., Zhang i, JiLong Zhang, I, JianLi Zhang, I, L., Zhang o, P., Zhang o, Y., Zhang i, Zhaxisangzhu, Q, X. X., Zhou t, F. R., Zhu i, Q. Q., Zhu i, G., Zizzi g, Barone, F, Melcarne, Akc, Cavaliere, S, Staiti, Gd, De Rosa, R, Piazzoli, Bd, DE VINCENZI, Mario, Feng, Zy, Gao, Xy, Garufi, F, Hu, Hb, Mu, J, Palummo, L, Segreto, A, Wang, Yg, Yang, Ht, Yu, Gc, Zhang, Jl, Bleve, Carla, CALABRESE MELCARNE, ANNA KAREN, G., D’Alì Staiti, Y. Q., Guo, R., Iuppa, Zizzi, Giovanni, DI GIROLAMO, Tristano, Aielli, G., Bacci, C., Barone, F., Bartoli, Bruno, Bernardini, P., Bleve, C., Branchini, P., Budano, A., Bussino, S., Calabrese Melcarne, A. K., Camarri, P., Cao, Z., Cappa, A., Cardarelli, R., Catalanotti, Sergio, Cattaneo, C., Cavaliere, Sergio, Celio, P., Chen, S. Z., Cheng, N., Creti, P., Cui, S. W., Dai, B. Z., D'Alì Staiti, G., Dattoli, M., De Mitri, I., DE ROSA, Rosario, D'ETTORRE PIAZZOLI, Benedetto, De Vincenzi, M., Ding, X. H., Di Sciascio, G., Feng, C. F., Galeazzi, F., Galeotti, P., Gao, X. Y., Gargana, R., Garufi, Fabio, Gou, Q. B., Guo, Y. Q., Huang, Q., Iacovacci, Michele, Iuppa, R., James, I., Jia, H. Y., Liberti, B., Liguori, G., Liu, C. Q., Liu, J., Lu, H., Mancarella, G., Mari, S. M., Marsella, G., Martello, D., Mastroianni, S., Meng, X. R., Mu, J., Ning, C. C., Palummo, L., Panareo, M., Perrone, L., Pistilli, P., Rossi, E., Ruggieri, F., Saggese, L., Salvini, P., Santonico, R., Segreto, A., Shen, P. R., Sheng, X. D., Shi, F., Stanescu, C., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, H., Wang, Y. G., Xu, B., Xue, L., Yang, H. T., Yang, Q. Y., Yang, X. C., Yuan, A. F., Zha, M., Zhang, H. M., Zhang, J. L., Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhou, X. X., Zhu, F. R., Zhu, Q. Q., AIELLI, G, BACCI, C, BARONE, F, BARTOLI, B, BERNARDINI, P, BI, XJ, BLEVE, C, BRANCHINI, P, BUDANO, A, BUSSINO, S, CALABRESE MELCARNE, AK, CAMARRI, P, CAO, Z, CAPPA, A, CARDARELLI, R, CATALANOTTI, S, CATTANEO, C, CAVALIERE, S, CELIO, P, CHEN, SZ, CHENG, N, CRETI, P, CUI, SW, DAI, BZ, D'ALI'STAITI, G, DANZENGLUOBU, DATTOLI, M, DE MITRI, I, DE ROSA, R, DETTORRE PIAZZOLI, B, DE VINCENZI, M, DI GIROLAMO, T, DING, XH, DI SCIASCIO, G, FENG, CF, FENG, ZHAOYANG, FENG, ZHENYONG, GALEAZZI, F, GALEOTTI, P, GAO, XY, GARGANA, R, GARUFI, F, GOU, QB, GUO, YQ, HE, HH, HU, HAIBING, HU, HONGBO, HUANG, Q, IACOVACCI, M, IUPPA, R, JAMES, I, JIA, HY, LABACIREN, LI, HJ, LI, JY, LIBERTI, B, LIGUORI, G, LIU, CQ, LIU, J, LU, H, MANCARELLA, G, MARI, SM, MARSELLA, G, MARTELLO, D, MASTROIANNI, S, MENG, XR, MU, J, NING, CC, PALUMMO, L, PANAREO, M, PERRONE, L, PISTILLI, P, QU, XB, ROSSI, E, RUGGIERI, F, SAGGESE, L, SALVINI, P, SANTONICO, R, SEGRETO, A, SHEN, PR, SHENG, XD, SHI, F, STANESCU, C, SURDO, A, TAN, YH, VALLANIA, P, VERNETTO, S, VIGORITO, C, WANG, H, WANG, YG, WU, CY, WU, HR, XU, B, XUE, L, YANG, HT, YANG, QY, YANG, XC, YU, GC, YUAN, AF, ZHA, M, ZHANG, HM, ZHANG, JL, ZHANG, L, ZHANG, P, ZHANG, XY, ZHANG, Y, ZHAXISANGZHU, ZHOU, XX, ZHU, FR, ZHU, QQ, and ZIZZI, G
Subjects: Nuclear and High Energy Physics, Gamma ray burst, Astrophysics::High Energy Astrophysical Phenomena, Air shower array, Astrophysics, Argo-Ybj, Settore FIS/05 - Astronomia e Astrofisica, Observatory, Gamma Rays Observations, Instrumentation, Zenith, Argo, Physics, Range (particle radiation), Apparati di sciame, Detector, Settore FIS/01 - Fisica Sperimentale, Gamma ray, Gamma ray bursts, Air shower arrays, Mode (statistics), Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Redshift, Air shower, Space and Planetary Science, Gamma Ray Bursts, Gamma Ray Emission, Astrophysics - High Energy Astrophysical Phenomena, Gamma-ray burst
Abstract: We report on the search for Gamma Ray Bursts (GRBs) in the energy range 1-100 GeV in coincidence with the prompt emission detected by satellites using the Astrophysical Radiation with Ground-based Observatory at YangBaJing (ARGO-YBJ) air shower detector. Thanks to its mountain location (Yangbajing, Tibet, P.R. China, 4300 m a.s.l.), active surface (about 6700 m**2 of Resistive Plate Chambers), and large field of view (about 2 sr, limited only by the atmospheric absorption), the ARGO-YBJ air shower detector is particularly suitable for the detection of unpredictable and short duration events such as GRBs. The search is carried out using the "single particle technique", i.e. counting all the particles hitting the detector without measurement of the energy and arrival direction of the primary gamma rays. Between 2004 December 17 and 2009 April 7, 81 GRBs detected by satellites occurred within the field of view of ARGO-YBJ (zenith angle < 45 deg). It was possible to examine 62 of these for >1 GeV counterpart in the ARGO-YBJ data finding no statistically significant emission. With a lack of detected spectra in this energy range fluence upper limits are profitable, especially when the redshift is known and the correction for the extragalactic absorption can be considered. The obtained fluence upper limits reach values as low as 10**{-5} erg cm**{-2} in the 1-100 GeV energy region. Besides this individual search for a higher energy counterpart, a statistical study of the stack of all the GRBs both in time and in phase was made, looking for a common feature in the GRB high energy emission. No significant signal has been detected., Comment: accepted for publication in ApJ
Published: 2008

38. Performance of the resistive plate chambers in the ARGO-YBJ experiment

Author: The Argo YBJ Collaboration: G. Aielli a, b, C. Bacci c, d, F. Barone e, f, B. Bartoli g, P. Bernardini h, i, X. J. Bi j, C. Bleve h, i, 1, P. Branchini d, A. Budano d, S. Bussino c, A. K. Calabrese Melcarne h, P. Camarri a, Z. Cao j, A. Cappa k, l, R. Cardarelli b, S. Catalanotti g, C. Cattaneo m, S. Cavaliere g, P. Celio c, S. Z. Chen j, N. Cheng j, P. Creti i, S. W. Cui n, G. Cusumano o, p, B. Z. Dai q, G. D’Alí Staiti p, r, Danzengluobu s, M. Dattoli k, l, t, I. De Mitri h, R. De Rosa g, B. D’Ettorre Piazzoli g, M. De Vincenzi c, T. Di Girolamo g, X. H. Ding s, G. Di Sciascio f, C. F. Feng u, Zhaoyang Feng j, ZhenyongFeng v, C. Ferrigno o, F. Galeazzi d, P. Galeotti k, t, X. Y. Gao q. R. Gargana d, F. Garufig, Q. B. Gou j, H. H. He j, Haibing Hu s, Hongbo Hu j, Q. Huang v, M. Iacovacci g, I. James m, w, H. Y. Jia v, Labaciren s, H. J. Li s, J. Y. Li u, B. Liberti b, G. Liguori m, C. Q. Liuq, J. Liu q, H. Lu j, G. Mancarella h, MARI, Stefano Maria, c, d, G. Marsella i, x, D. Martello h, S. Mastroianni c, X. R. Meng s, J. Mu q, L. Nicastro p, y, C. C. Ning s, L. Palummo a, M. Panareo i, L. Perrone i, P. Pistilli c, X. B. Qu u, E. Rossi f, F. Ruggieri d, L. Saggese g, P. Salvini m, R. Santonico a, A. Segreto o, P. R. Shen j, X. D. Sheng j, F. Shi j, C. Stanescu d, A. Surdo i, Y. H. Tan j, P. Vallania k, S. Vernetto k, C. Vigorito k, H. Wang j, Y. G. Wang j, C. Y. Wu j, H. R. Wu j, B. Xu v, L. Xue u, H. T. Yang q, Q. Y. Yang q, X. C. Yang q, G. C. Yu v, A. F. Yuan s, M. Zha j, H. M. Zhang j, J. L. Zhang j, L. Zhang q, P. Zhang q, X. Y. Zhang u, Y. Zhang j, Zhaxisangzhu s, X. X. Zhou v, F. R. Zhu j, Q. Q. Zhu j, G. Zizzi h, The Argo YBJ Collaboration: G., Aielli a, B, C., Bacci c, D, F., Barone e, F, B., Bartoli g, P., Bernardini h, I, X. J., Bi j, C., Bleve h, I, 1, P., Branchini d, A., Budano d, S., Bussino c, A. K., Calabrese Melcarne h, P., Camarri a, Z., Cao j, A., Cappa k, L, R., Cardarelli b, S., Catalanotti g, C., Cattaneo m, S., Cavaliere g, P., Celio c, S. Z., Chen j, N., Cheng j, P., Creti i, S. W., Cui n, G., Cusumano o, P, B. Z., Dai q, G., D’Alí Staiti p, R, Danzengluobu, S, M., Dattoli k, L, T, I., De Mitri h, R., De Rosa g, B., D’Ettorre Piazzoli g, M., De Vincenzi c, T., Di Girolamo g, X. H., Ding, G., Di Sciascio f, C. F., Feng u, Zhaoyang Feng, J, Zhenyongfeng, V, C., Ferrigno o, F., Galeazzi d, P., Galeotti k, T, X. Y. Gao q. R., Gargana d, F., Garufig, Q. B., Gou j, H. H., He j, Haibing Hu, S, Hongbo Hu, J, Q., Huang v, M., Iacovacci g, I., James m, W, H. Y., Jia v, Labaciren, S, H. J., Li, J. Y., Li u, B., Liberti b, G., Liguori m, C. Q., Liuq, J., Liu q, H., Lu j, G., Mancarella h, Mari, Stefano Maria, C, D, G., Marsella i, X, D., Martello h, S., Mastroianni c, X. R., Meng, J., Mu q, L., Nicastro p, Y, C. C., Ning, L., Palummo a, M., Panareo i, L., Perrone i, P., Pistilli c, X. B., Qu u, E., Rossi f, F., Ruggieri d, L., Saggese g, P., Salvini m, R., Santonico a, A., Segreto o, P. R., Shen j, X. D., Sheng j, F., Shi j, C., Stanescu d, A., Surdo i, Y. H., Tan j, P., Vallania k, S., Vernetto k, C., Vigorito k, H., Wang j, Y. G., Wang j, C. Y., Wu j, H. R., Wu j, B., Xu v, L., Xue u, H. T., Yang q, Q. Y., Yang q, X. C., Yang q, G. C., Yu v, A. F., Yuan, M., Zha j, H. M., Zhang j, J. L., Zhang j, L., Zhang q, P., Zhang q, X. Y., Zhang u, Y., Zhang j, Zhaxisangzhu, S, X. X., Zhou v, F. R., Zhu j, Q. Q., Zhu j, G., Zizzi h, G., Aielli, C., Bacci, F., Barone, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, P., Branchini, A., Budano, S., Bussino, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, A., Cappa, R., Cardarelli, S., Catalanotti, C., Cattaneo, S., Cavaliere, P., Celio, S. Z., Chen, N., Cheng, P., Creti, S. W., Cui, G., Cusumano, B. Z., Dai, G., D’Alí Staiti, Danzengluobu, M., Dattoli, DE MITRI, Ivan, R., De Rosa, B., D’Ettorre Piazzoli, M., De Vincenzi, T., Di Girolamo, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, C., Ferrigno, F., Galeazzi, P., Galeotti, X. Y., Gao, R., Gargana, F., Garufi, Q. B., Gou, H. H., He, Haibing, Hu, Hongbo, Hu, Q., Huang, M., Iacovacci, I., Jame, H. Y., Jia, Labaciren, J. Y., Li, B., Liberti, G., Liguori, C. Q., Liu, J., Liu, H., Lu, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, J., Mu, L., Nicastro, L., Palummo, Panareo, Marco, Perrone, Lorenzo, P., Pistilli, X. B., Qu, E., Rossi, F., Ruggieri, L., Saggese, P., Salvini, R., Santonico, A., Segreto, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, H., Wang, Y. G., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, H. T., Yang, Q. Y., Yang, X. C., Yang, G. C., Yu, M., Zha, H. M., Zhang, J. L., Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, Zhaxisangzhu, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, and G., Zizzi
Subjects: Physics, Nuclear and High Energy Physics, Range (particle radiation), Resistive touchscreen, Gamma-ray astronomy, Physics::Instrumentation and Detectors, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Detector, Settore FIS/01 - Fisica Sperimentale, Extensive Air Shower, Extensive Air Showers, Resistive Plate Chambers, Resistive Plate Chambers, Extensive Air Showers, Gamma-ray astronomy, Nuclear physics, Optics, Sampling (signal processing), High Energy Physics::Experiment, Current (fluid), business, Instrumentation, Energy (signal processing), Order of magnitude, Argo
Abstract: The ARGO-YBJ experiment is designed for the detection of Extensive Air Showers (EAS) in the primary energy range 100 GeV–10 TeV. Its full-coverage feature allows to lower the energy threshold about one order of magnitude with respect to sampling EAS detectors. Here the performance of the RPC array is described and the current status of the experiment is presented.
Published: 2007

39. Age determination of plutonium material by alpha spectrometry and thermal ionization mass spectrometry

Author: Y. H. Dai, F. R. Zhu, L. X. Zhang, Hai-Tao Zhang, J. Xu, X. W. Yi, D. M. Li, and Y. G. Zhao
Subjects: Alpha spectrometry, Chemistry, Radiochemistry, Analytical chemistry, chemistry.chemical_element, Physical and Theoretical Chemistry, Thermal ionization mass spectrometry, Plutonium
Abstract: Summary Age is a key parameter to deduce the history of a plutonium material. An experimental method using both alpha spectrometry and thermal ionization mass spectrometry has been developed for the age determination of plutonium material. This method is based on the parent/daughter pair 241Pu/241Am ratio and has been validated using several plutonium source of known age. The results obtained are in good agreement with the last purification date of plutonium source.
Published: 2008

40. Reconciling the light component and all-particle cosmic ray energy spectra at the knee

Author: Huan-Yu Jia, Y. X. Zhao, and F. R. Zhu
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Nuclear and High Energy Physics, Component (thermodynamics), Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics, Spectral line, Acceleration, Energy spectrum, Particle, Astrophysics - High Energy Astrophysical Phenomena, Instrumentation, Energy (signal processing)
Abstract: The knee phenomenon of the cosmic ray spectrum, which plays an important role in studying the acceleration mechanism of cosmic rays, is still an unsolved mystery. We try to reconcile the knee spectra measured by ARGO-YBJ and Tibet-III. A simple broken power-law model fails to explain the experimental data. Therefore a modified broken power-law model with non-linear acceleration effects is adopted, which can describe the sharp knee structure. This model predicts that heavy elements dominate at the knee., Comment: 5 pages, 5 figures
Published: 2015
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41. Observation of TeV gamma rays from the Cygnus region with the ARGO-YBJ experiment

Author: Carla Bleve, Q. Q. Zhu, B. S. Wang, Zhaxisangzhu, Hongbo Hu, C. F. Feng, B. Bartoli, Carlo Vigorito, S. M. Mari, A. F. Yuan, X. D. Sheng, Zhengguo Cao, Paolo Montini, T. Di Girolamo, G. Liguori, B. D'Ettorre Piazzoli, R. Iuppa, L. L. Ma, Haibing Hu, Jilong Zhang, Y. Q. Guo, E. Giroletti, Y. B. Chen, H. J. Li, Chang-Chun Ning, Zhaoyang Feng, H. R. Wu, F. Ruggieri, Y. Zhang, P. Bernardini, S. W. Cui, D. Martello, B. Panico, Labaciren, Jianli Zhang, L. Xue, M. Iacovacci, M. Zha, M. Y. Liu, P. R. Shen, X. Y. Zhang, B. Z. Dai, J. K. K. Liu, Antonio Budano, P. Pistilli, H. M. Zhang, X. X. Zhou, C. Cattaneo, H. Y. Jia, X. H. Ding, Hong-peng Lu, Q. Y. Yang, Zhaxiciren, P. Creti, A. K. Calabrese Melcarne, P. F. Zhang, Cristian Stanescu, P. Branchini, A. Surdo, Roberto Cardarelli, Danzengluobu, G. Zizzi, Q. Huang, X. J. Bi, G. Marsella, Zhenyong Feng, F. R. Zhu, S. Vernetto, C. Liu, Bingwei Xu, X. X. Li, S. Catalanotti, Paolo Camarri, Z. G. Yao, H.H. He, M. Dattoli, M. Panareo, Huaguang Wang, Y. H. Tan, X. H. Ma, Q. B. Gou, I. De Mitri, J. B. Zhao, P. Salvini, Fudong Shi, A. Pagliaro, S. Mastroianni, J. Y. Li, T. L. Chen, I. Bolognino, S. Z. Chen, Giovanni Mancarella, G. Di Sciascio, X. C. Yang, R. Santonico, Irina James, L. Perrone, F. Galeazzi, Longzhou Zhang, C. Y. Wu, C. Q. Liu, G. D'Alí Staiti, P. Vallania, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, I., Bolognino, P., Branchini, A., Budano, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, R., Cardarelli, S., Catalanotti, C., Cattaneo, S. Z., Chen, T. L., Chen, Y., Chen, P., Creti, S. W., Cui, B. Z., Dai, G., D'Alí Staiti, Danzengluobu, M., Dattoli, DE MITRI, Ivan, B., D'Ettorre Piazzoli, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, F., Galeazzi, E., Giroletti, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Hu, Hongbo, Hu, Q., Huang, M., Iacovacci, R., Iuppa, I., Jame, H. Y., Jia, Labaciren, H. J., Li, J. Y., Li, X. X., Li, G., Liguori, C., Liu, C. Q., Liu, J., Liu, M. Y., Liu, H., Lu, L. L., Ma, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, A., Pagliaro, Panareo, Marco, B., Panico, Perrone, Lorenzo, P., Pistilli, F., Ruggieri, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, B., Wang, H., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, Jilong, Zhang, Jianli, Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, J., Zhao, Zhaxiciren, Zhaxisangzhu, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, G., Zizzi, Bartoli, Bruno, Bernardini, P., Bleve, C., Bolognino, I., Branchini, P., Budano, A., A. K. C., Camarri, P., Cao, Z., Cardarelli, R., Catalanotti, Sergio, Cattaneo, C., Chen, S. Z., Chen, T. L., Chen, Y., Creti, P., Cui, S. W., Dai, B. Z., Staiti, G. D., Dattoli, M., Mitri, I. D., D'ETTORRE PIAZZOLI, Benedetto, DI GIROLAMO, Tristano, Ding, X. H., Sciascio, G. D., Feng, C. F., Feng, Z. Y., Galeazzi, F., Giroletti, E., Gou, Q. B., Guo, Y. Q., H. B., Hu, Huang, Q., Iacovacci, Michele, Iuppa, R., James, I., Jia, H. Y., Liguori, G., Liu, C., Liu, C. Q., Liu, J., Liu, M. Y., Lu, H., Mancarella, G., Mari, S. M., Marsella, G., Martello, D., Mastroianni, S., Montini, P., Ning, C. C., Pagliaro, A., Panareo, M., Panico, B., Perrone, L., Pistilli, P., Ruggieri, F., Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Stanescu, C., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, B., Wang, H., Xu, B., Xue, L., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M., Zhang, H. M., Zhang, J. L., Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhao, J., Zhou, X. X., Zhu, F. R., Zhu, Q. Q., Zizzi, G., Bartoli, B, Bernardini, P, Bi, XJ, Bleve, C, Bolognino, I, Branchini, P, Budano, A, Calabrese Melcarne, AK, Camarri, P, Cao, Z, Cardarelli, R, Catalanotti, S, Cattaneo, C, Chen, SZ, Chen, TL, Chen, Y, Creti, P, Cui, SW, Dai, BZ, D’Ali Staiti, G, Dattoli, M, De Mitri, I, D’Ettorre Piazzoli, B, Di Girolamo, T, Ding, XH, Di Sciascio, G, Feng, CF, Feng, ZYa, Feng, ZYo, Galeazzi, F, Giroletti, E, Gou, QB, Guo, YQ, He, HH, Hu, HBi, Hu, HBo, Huang, Q, Iacovacci, M, Iuppa, R, James, I, Jia, HY, Li, HJ, Li, JY, Li, XX, Liguori, G, Liu, C, Liu, CQ, Liu, J, Liu, MY, Lu, H, Ma, LL, Ma, XH, Mancarella, G, Mari, SM, Marsella, G, Martello, D, Mastroianni, S, Montini, P, Ning, CC, Pagliaro, A, Panareo, M, Panico, B, Perrone, L, Pistilli, P, Ruggieri, F, Salvini, P, Santonico, R, Shen, PR, Sheng, XD, Shi, F, Stanescu, C, Surdo, A, Tan, YH, Vallania, P, Vernetto, S, Vigorito, C, Wang, B, Wang, H, Wu, CY, Wu, HR, Xu, B, Xue, L, Yang, QY, Yang, XC, Yao, ZG, Yuan, AF, M. Zha, M, Zhang, HM, Zhang, JLi, Zhang, JLo, Zhang, L, Zhang, P, Zhang, XY, Zhang, Y, Zhao, J, Zhaxiciren, Zhaxisangzhu, Zhou, XX, Zhu, FR, Zhu, QQ, Zizzi, G, Bartoli, B., Bi, X. J., Melcarne A. K., Calabrese, Catalanotti, S., Staiti G., D'Ali, De Mitri, I., Piazzoli B., D'Ettorre, Di Girolamo, T., Di Sciascio, G., Feng, Zhaoyang, Feng, Zhenyong, He, H. H., Hu, Haibing, Hu, Hongbo, Iacovacci, M., Li, H. J., Li, J. Y., Li, X. X., Ma, L. L., Ma, X. H., Mari, Stefano Maria, Wu, C. Y., Wu, H. R., Zhang, Jilong, and Zhang, Jianli
Subjects: Astrophysics::High Energy Astrophysical Phenomena, general – pulsars: individual (MGRO J2019+37 [Gamma rays], Flux, FOS: Physical sciences, Astrophysics, 01 natural sciences, Pulsar wind nebula, general – pulsar, 0103 physical sciences, MILAGRO, 010303 astronomy & astrophysics, DETECTOR, Argo, Physics, CALIBRATION, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, MGRO J2031+41), Settore FIS/01 - Fisica Sperimentale, Gamma ray, Astronomy and Astrophysics, individual (MGRO J2019+37, MGRO J2031+41), PLANE, 3. Good health, Medium energy, Crab Nebula, gamma ray, 13. Climate action, Space and Planetary Science, GALACTIC SOURCES, J2032+4130, Milagro, gamma rays, general – pulsars, EMISSION, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report the observation of TeV gamma-rays from the Cygnus region using the ARGO-YBJ data collected from 2007 November to 2011 August. Several TeV sources are located in this region including the two bright extended MGRO J2019+37 and MGRO J2031+41. According to the Milagro data set, at 20 TeV MGRO J2019+37 is the most significant source apart from the Crab Nebula. No signal from MGRO J2019+37 is detected by the ARGO-YBJ experiment, and the derived flux upper limits at 90% confidence level for all the events above 600 GeV with medium energy of 3 TeV are lower than the Milagro flux, implying that the source might be variable and hard to be identified as a pulsar wind nebula. The only statistically significant (6.4 standard deviations) gamma-ray signal is found from MGRO J2031+41, with a flux consistent with the measurement by Milagro., 14 pages, 4 figures
Published: 2012

42. Measurement of the cosmic ray antiproton/proton flux ratio at TeV energies with the ARGO-YBJ detector

Author: X. X. Li, I. De Mitri, M. Iacovacci, M. Zha, G. D'Alí Staiti, Zhenyong Feng, P. Vallania, S. Vernetto, C. Cattaneo, F. R. Zhu, C. Liu, T. L. Chen, X. H. Ma, H.H. He, S. W. Cui, Jilong Zhang, F. Ruggieri, Q. Q. Zhu, P. Bernardini, S. Catalanotti, M. Panareo, Giovanni Mancarella, T. Di Girolamo, B. D'Ettorre Piazzoli, Y. Q. Guo, Carla Bleve, C. Y. Wu, E. Giroletti, B. Panico, P. Salvini, Zhaxiciren, R. Santonico, Zihuang Cao, Y. B. Chen, H. J. Li, Paolo Camarri, C. Q. Liu, H. R. Wu, Hongbo Hu, L. Xue, C. F. Feng, A. K. Calabrese Melcarne, A. F. Yuan, Carlo Vigorito, B. Z. Dai, Paolo Montini, R. Iuppa, B. Bartoli, Hong-peng Lu, X. Y. Zhang, X. C. Yang, G. Marsella, Haibing Hu, Cristian Stanescu, P. Branchini, Y. X. Yan, Antonio Budano, B. S. Wang, J. K. K. Liu, Zhaxisangzhu, Labaciren, Irina James, Y. Zhang, Chang-Chun Ning, Zhaoyang Feng, D. Martello, Longzhou Zhang, L. Perrone, Jianli Zhang, P. Creti, P. Pistilli, H. M. Zhang, X. X. Zhou, Z. G. Yao, Bingwei Xu, A. Surdo, Q. Huang, Huaguang Wang, G. Liguori, Fudong Shi, S. Mastroianni, Q. B. Gou, X. D. Sheng, P. R. Shen, P. F. Zhang, X. J. Bi, S. Z. Chen, S. M. Mari, X. B. Qu, X. H. Ding, Roberto Cardarelli, G. Di Sciascio, Y. H. Tan, J. Y. Li, M. Y. Liu, Q. Y. Yang, H. Y. Jia, Danzengluobu, G. Zizzi, I. Bolognino, A. Pagliaro, Bartoli, B., Bernardini, P., Bi, X. J., Bleve, C., Bolognino, I., Branchini, P., Budano, A., Melcarne A. K., Calabrese, Camarri, P., Cao, Z., Cardarelli, R., Catalanotti, S., Cattaneo, C., Chen, S. Z., Chen, T. L., Chen, Y., Creti, P., Cui, S. W., Dai, B. Z., Staiti G., D'Ali, Danzengluobu, De Mitri, I., Piazzoli B., D'Ettorre, Di Girolamo, T., Ding, X. H., Di Sciascio, G., Feng, C. F., Feng, Zhaoyang, Feng, Zhenyong, Giroletti, E., Gou, Q. B., Guo, Y. Q., He, H. H., Hu, Haibing, Hu, Hongbo, Huang, Q., Iacovacci, M., Iuppa, R., James, I., Jia, H. Y., Labaciren, Li, H. J., Li, J. Y., Li, X. X., Liguori, G., Liu, C., Liu, C. Q., Liu, J., Liu, M. Y., Lu, H., Ma, X. H., Mancarella, G., Mari, Stefano Maria, Marsella, G., Martello, D., Mastroianni, S., Montini, P., Ning, C. C., Pagliaro, A., Panareo, M., Panico, B., Perrone, L., Pistilli, P., Qu, X. B., Ruggieri, F., Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Stanescu, C., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, B., Wang, H., Wu, C. Y., Wu, H. R., Xu, B., Xue, L., Yan, Y. X., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M., Zhang, H. M., Zhang, Jilong, Zhang, Jianli, Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhaxiciren, Zhaxisangzhu, Zhou, X. X., Zhu, F. R., Zhu, Q. Q., Zizzi, G., Bartoli, Bruno, Bi, X., Calabrese Melcarne, A., Catalanotti, Sergio, Chen, S., Chen, T., Cui, S., Dai, B., D’Alí Staiti, G., D'ETTORRE PIAZZOLI, Benedetto, DI GIROLAMO, Tristano, Ding, X., Feng, C., Zhaoyang, Feng, Zhenyong, Feng, Gou, Q., Guo, Y., He, H., Haibing, Hu, Hongbo, Hu, Iacovacci, Michele, Jia, H., Li, H., Li, J., Li, X., Liu, M., Ma, X., Mari, S., Ning, C., Qu, X., Shen, P., Sheng, X., Tan, Y., Wu, C., Wu, H., Yan, Y., Yang, Q., Yang, X., Yao, Z., Yuan, A., Zhang, H., Jilong, Zhang, Jianli, Zhang, Zhang, X., Zhou, X., Zhu, F., Zhu, Q., Bartoli, B, Bernardini, P, Bi, XJ, Bleve, C, Bolognino, I, Branchini, P, Budano, A, Calabrese Melcarne, AK, Camarri, P, Cao, Z, Cardarelli, R, Catalanotti, S, Cattaneo, C, Chen, SZ, Chen, TL, Chen, Y, Creti, P, Cui, SW, Dai, BZ, D’Ali' Staiti, G, De Mitri, I, D’Ettorre Piazzoli, B, Di Girolamo, T, Ding, XH, Di Sciascio, G, Feng, CF, Feng, ZYa, Feng, ZYo, Giroletti, E, Gou, QB, Guo, YQ, He, HH, Hu, HBa, Hu, HBo, Huang, Q, Iacovacci, M, Iuppa, R, James, I, Jia, HY, Li, HJ, Li, JY, Li, XX, Liguori, G, Liu, C, Liu, CQ, Liu, J, Liu, MY, Lu, H, Ma, XH, Mancarella, G, Mari, SM, Marsella, G, Martello, D, Mastroianni, S, Montini, P, Ning, CC, Pagliaro, A, Panareo, M, Panico, B, Perrone, L, Pistilli, P, Qu, XB, Ruggieri, F, Salvini, P, Santonico, R, Shen, PR, Sheng, XD, Shi, F, Stanescu, C, Surdo, A, Tan, YH, Vallania, P, Vernetto, S, Vigorito, C, Wang, B, Wang, H, Wu, CY, Wu, HR, Xu B, Xue, L, Yan, YX, Yang, QY, Yang, XC, Yao, ZG, Yuan, AF, Zha, M, Zhang, HM, Zhang, JLo, Zhang, JLi, Zhang, L, Zhang, P, Zhang, XY, Zhang, Y, Zhaxiciren, Zhaxisangzhu, Zhou, XX, Zhu, FR, Zhu, QQ, Zizzi, G, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, I., Bolognino, P., Branchini, A., Budano, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, R., Cardarelli, S., Catalanotti, C., Cattaneo, S. Z., Chen, T. L., Chen, Y., Chen, P., Creti, S. W., Cui, B. Z., Dai, G., D’Alí Staiti, DE MITRI, Ivan, B., D’Ettorre Piazzoli, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, E., Giroletti, Q. B., Gou, Y. Q., Guo, H. H., He, Q., Huang, M., Iacovacci, R., Iuppa, I., Jame, H. Y., Jia, H. J., Li, J. Y., Li, X. X., Li, G., Liguori, C., Liu, C. Q., Liu, J., Liu, M. Y., Liu, H., Lu, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, A., Pagliaro, Panareo, Marco, B., Panico, Perrone, Lorenzo, P., Pistilli, X. B., Qu, F., Ruggieri, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, B., Wang, H., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, Y. X., Yan, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, and G., Zizzi
Subjects: Physics, Nuclear and High Energy Physics, Antiparticle, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, Settore FIS/01 - Fisica Sperimentale, Earth-Moon, Cosmic ray, magnetic spectrometer, High Energy Physics - Experiment, Nuclear physics, Earth's magnetic field, Antiproton, Antimatter, antiproton, Content (measure theory), Antiproton-Proton ratio, Cosmic rays, Extended Air Showers, Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing)
Abstract: Cosmic ray antiprotons provide an important probe to study the cosmic ray propagation in the interstellar space and to investigate the existence of dark matter. Acting the Earth-Moon system as a magnetic spectrometer, paths of primary antiprotons are deflected in the opposite sense with respect to those of the protons in their way to the Earth. This effect allows, in principle, the search for antiparticles in the direction opposite to the observed deficit of cosmic rays due to the Moon (the so-called `Moon shadow'). The ARGO-YBJ experiment, located at the Yangbajing Cosmic Ray Laboratory (Tibet, P.R. China, 4300 m a.s.l., 606 g/cm$^2$), is particularly effective in measuring the cosmic ray antimatter content via the observation of the cosmic rays shadowing effect due to: (1) good angular resolution, pointing accuracy and long-term stability; (2) low energy threshold; (3) real sensitivity to the geomagnetic field. Based on all the data recorded during the period from July 2006 through November 2009 and on a full Monte Carlo simulation, we searched for the existence of the shadow cast by antiprotons in the TeV energy region. No evidence of the existence of antiprotons is found in this energy region. Upper limits to the $\bar{p}/p$ flux ratio are set to 5 % at a median energy of 1.4 TeV and 6 % at 5 TeV with a confidence level of 90%. In the TeV energy range these limits are the lowest available., Comment: Contact authors: G. Di Sciascio (disciascio@roma2.infn.it) and R. Iuppa (iuppa@roma2.infn.it), INFN Sezione di Roma Tor Vergata, Roma, Italy
Published: 2012

43. Calibration of the RPC charge readout in the ARGO-YBJ experiment

Author: M. Iacovacci, M. Zha, Hongbo Hu, C. Liu, A. Surdo, Y. B. Chen, Q. Y. Yang, Yicheng Guo, Y. X. Yan, Danzengluobu, X. H. Ma, P. Creti, B. Liberti, A. F. Yuan, Huihai He, G. Zizzi, P. F. Zhang, Haifeng Li, Paolo Bernardini, R. Santonico, X. C. Yang, X. J. Bi, X. Y. Zhang, R. Gargana, Minghui Liu, S. Z. Chen, X. X. Li, Labaciren, L. Zhang, A. Pagliaro, C. Cattaneo, F. Shi, A. Cappa, Irina James, Piero Vallania, X. B. Qu, S. Catalanotti, X. H. Ding, B. S. Wang, Zhaxisangzhu, P. Salvini, L. Perrone, G. Di Sciascio, A. K. Calabrese Melcarne, Jilong Zhang, Y. H. Tan, M. De Vincenzi, R. Cardarelli, S. M. Mari, Cunfeng Feng, G. D'Alí Staiti, E. Rossi, N. Cheng, Jianli Zhang, Paolo Montini, R. Iuppa, H. Y. Jia, S. Vernetto, C. Bacci, P. Camarri, G. Mancarella, J. K. K. Liu, C. Y. Wu, L. Saggese, Zihuang Cao, I. De Mitri, T. L. Chen, H. M. Zhang, M. Dattoli, H. Lu, G. Liguori, C. X. Liu, F. Galeazzi, B. Bartoli, T. Di Girolamo, P. Celio, G. Aielli, B. D'Ettorre Piazzoli, Bingwei Xu, Severino Angelo Maria Bussino, P. R. Shen, L. Xue, Q. B. Gou, Carlo Vigorito, Xiangdong Sheng, P. Pistilli, X. X. Zhou, P. Galeotti, Q. Huang, Haibing Hu, C. Bleve, Y. Zhang, D. Martello, Zhenyong Feng, A. Budano, S. Mastroianni, H. R. Wu, H. W. Wang, B. Z. Dai, F. Ruggieri, F. R. Zhu, M. Panareo, Q. Q. Zhu, P. Branchini, G. Marsella, X. R. Meng, C. Stanescu, Chang-Chun Ning, Zhaoyang Feng, S. W. Cui, J. Y. Li, Bartoli, Bruno, Catalanotti, Sergio, D'ETTORRE PIAZZOLI, Benedetto, DI GIROLAMO, Tristano, Iacovacci, Michele, Aielli, G, Bacci, C, Bartoli, B, Bernardini, P, Bi, Xj, Bleve, C, Branchini, P, Budano, A, Bussino, Severino Angelo Maria, Calabrese Melcarne, Ak, Camarri, P, Cao, Z, Cappa, A, Cardarelli, R, Catalanotti, S, Cattaneo, C, Celio, P, Chen, Sz, Chen, Tl, Chen, Y, Cheng, N, Creti, P, Cui, Sw, Dai, Bz, D'Ali Staiti, G, Danzengluobu, Dattoli, M, De Mitri, I, D'Ettorre Piazzoli, B, DE VINCENZI, Mario, Di Girolamo, T, Ding, Xh, Di Sciascio, G, Feng, Cf, Feng Zhao, Yang, Feng Zhen, Yong, Galeazzi, F, Galeotti, P, Gargana, R, Gou, Qb, Guo, Yq, He, Hh, Hu, Haibing, Hu Hong, Bo, Huang, Q, Iacovacci, M, Iuppa, R, James, I, Jia, Hy, Labaciren, Li, Hj, Li, Jy, Li, Xx, Liberti, B, Liguori, G, Liu, C, Liu, Cq, Liu, My, Liu, J, Lu, H, Ma, Xh, Mancarella, G, Mari, Stefano Maria, Marsella, G, Martello, D, Mastroianni, S, Meng, Xr, Montini, P, Ning, Cc, Pagliaro, A, Panareo, M, Perrone, L, Pistilli, P, Qu, Xb, Rossi, E, Ruggieri, F, Saggese, L, Salvini, P, Santonico, R, Shen, Pr, Sheng, Xd, Shi, F, Stanescu, C, Surdo, A, Tan, Yh, Vallania, P, Vernetto, S, Vigorito, C, Wang, B, Wang, H, Wu, Cy, Wu, Hr, Xu, B, Xue, L, Yan, Yx, Yang, Qy, Yang, Xc, Yuan, Af, Zha, M, Zhang, Hm, Zhang Ji, Long, Zhang Jian, Li, Zhang, L, Zhang, P, Zhang, Xy, Zhang, Y, Zhaxisangzhu, Zhou, Xx, Zhu, Fr, Zhu, Qq, Zizzi, G., Bi, XJ, Bussino, S, Calabrese Melcarne, AK, Chen, SZ, Chen, TL, Cui, SW, Dai, BZ, De Vincenzi, M, Ding, XH, Feng, CF, Feng, ZYa, Feng, ZYo, Gou, QB, Guo, YQ, He, HH, Hu, HaB, Hu, HoB, Jia, HY, Li, HJ, Li, JY, Li, XX, Liu, CQ, Liu, MY, Ma, XH, Mari, SM, Meng, XR, Ning, CC, Qu XB, Shen, PR, Sheng, XD, Tan, YH, Wu, CY, Wu, HR, Yan, YX, Yang, QY, Yang, XC, Yuan, AF, Zhang, HM, Zhang, JLi, Zhang, JLo, Zhang, XY, Zhou, XX, Zhu, FR, Zhu, QQ, Zizzi, G, G., Aielli, C., Bacci, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, P., Branchini, A., Budano, S., Bussino, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, A., Cappa, R., Cardarelli, S., Catalanotti, C., Cattaneo, P., Celio, S. Z., Chen, T. L., Chen, Y., Chen, N., Cheng, P., Creti, S. W., Cui, B. Z., Dai, G., D’Alı´ Staiti, M., Dattoli, DE MITRI, Ivan, B., D’Ettorre Piazzoli, M., De Vincenzi, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, F., Galeazzi, P., Galeotti, R., Gargana, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Hu, Hongbo, Hu, Q., Huang, M., Iacovacci, R., Iuppa, I., Jame, H. Y., Jia, H. J., Li, J. Y., Li, X. X., Li, B., Liberti, G., Liguori, C., Liu, C. Q., Liu, M. Y., Liu, J., Liu, H., Lu, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, X. R., Meng, P., Montini, C. C., Ning, A., Pagliaro, Panareo, Marco, Perrone, Lorenzo, P., Pistilli, X. B., Qu, E., Rossi, F., Ruggieri, L., Saggese, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, B., Wang, H., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, Y. X., Yan, Q. Y., Yang, X. C., Yang, A. F., Yuan, M., Zha, H. M., Zhang, Jilong, Zhang, Jianli, Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, and G., Zizzi
Subjects: Optical telescopes, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Camere a Piastre Resistive (RPC), Resistive plate chamber, Astrophysics::High Energy Astrophysical Phenomena, Cosmic ray, law.invention, Telescope, Settore FIS/05 - Astronomia E Astrofisica, Optics, law, Coincident, Air showers, Calibration, Sea level, Instrumentation, Particle densities, Cosmic rays, Resistive Plate Chambers, Charge read-out, Extended Air Showers, Physics, Air showers, Charge readout, Dynamic range, Knee regions, Particle densities, Resistive plate chambers, Calibration, Charged particles, Cosmic rays, Experiments, Optical telescopes, Sea level, Telescopes, Particle spectrometers, Resistive touchscreen, Scintillation, Dynamic range, Charge readout, business.industry, Charged particles, Settore FIS/01 - Fisica Sperimentale, Astrophysics::Instrumentation and Methods for Astrophysics, Charged particle, Air shower, Calibrazione della Risposta Analogica di RPC, Knee regions, Lettura Analogica di RPC, Resistive plate chambers, business, Experiments, Telescopes
Abstract: ""The charge readout of Resistive Plate Chambers (RPCs) is implemented in the ARGO-YBJ experiment to measure the charged particle density of the shower front up to 10^4\\\/m^2, enabling the study of the primary cosmic rays with energies in the ''knee'' region. As the first time for RPCs being used this way, a telescope with RPCs and scintillation detectors is setup to calibrate the number of charged particles hitting a RPC versus its charge readout. Air shower particles are taken as the calibration beam. The telescope was tested at sea level and then moved to the ARGO-YBJ site for coincident operation with the ARGO-YBJ experiment. The charge readout shows good linearity with the particle density in the dynamic range (up to 200\\\/m^2).""
Published: 2012

44. Gamma-Ray Astronomy with ARGO-YBJ

Author: B. Bartoli, X. J. Bi, C. Bleve, I. Bolognino, P. Branchini, A. Budano, A. K. Calabrese Melcarne, P. Camarri, Z. Cao, A. Cappa, R. Cardarelli, S. Catalanotti, C. Cattaneo, P. Celio, S. Z. Chen, T. L. Chen, Y. Chen, P. Creti, S. W. Cui, B. Z. Dai, G. D’Ali´ Staiti, Danzengluobu, M. Dattoli, B. D’Ettorre Piazzoli, T. Di Girolamo, X. H. Ding, G. Di Sciascio, C. F. Feng, Zhaoyang Feng, Zhenyong Feng, F. Galeazzi, P. Galeotti, E. Giroletti, Q. B. Gou, Y. Q. Guo, H. H. He, Haibing Huo, Hongbo Hue, Q. Huang, M. Iacovacci, R. Iuppa, I. James, H. Y. Jia, Labaciren, H. J. Li, J. Y. Li, X. X. Li, G. Liguori, C. Liu, C. Q. Liu, J. Liu, M. Y. Liu, H. Lu, X. H. Ma, S. M. Mari, S. Mastroianni, P. Montini, C. C. Ning, A. Pagliaro, B. Panico, P. Pistilli, X. B. Qu, E. Rossi, F. Ruggieri, P. Salvini, R. Santonico, P. R. Shen, X. D. Sheng, F. Shi, C. Stanescu, A. Surdo, Y. H. Tan, P. Vallania, S. Vernetto, C. Vigorito, B. Wang, H. Wang, C. Y. Wu, H. R. Wu, B. Xu, L. Xue, Y. X. Yan, Q. Y. Yang, X. C. Yang, Z. G. Yao, A. F. Yuan, M. Zha, H. M. Zhang, JilongZhang, JianliZhang, L. Zhang, P. Zhang, X. Y. Zhang, Y. Zhang, Zhaxiciren, Zhaxisangzhu, X. X. Zhou, F. R. Zhu, Q. Q. Zhu, G. Zizzi, BERNARDINI, Paolo, DE MITRI, Ivan, MANCARELLA, Giovanni, MARSELLA, GIOVANNI, MARTELLO, Daniele, PANAREO, Marco, PERRONE, Lorenzo, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, I., Bolognino, P., Branchini, A., Budano, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, A., Cappa, R., Cardarelli, S., Catalanotti, C., Cattaneo, P., Celio, S. Z., Chen, T. L., Chen, Y., Chen, P., Creti, S. W., Cui, B. Z., Dai, G., D’Ali´ Staiti, Danzengluobu, M., Dattoli, DE MITRI, Ivan, B., D’Ettorre Piazzoli, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, F., Galeazzi, P., Galeotti, E., Giroletti, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Huo, Hongbo, Hue, Q., Huang, M., Iacovacci, R., Iuppa, I., Jame, H. Y., Jia, Labaciren, H. J., Li, J. Y., Li, X. X., Li, G., Liguori, C., Liu, C. Q., Liu, J., Liu, M. Y., Liu, H., Lu, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, A., Pagliaro, Panareo, Marco, B., Panico, Perrone, Lorenzo, P., Pistilli, X. B., Qu, E., Rossi, F., Ruggieri, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, B., Wang, H., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, Y. X., Yan, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, Jilongzhang, Jianlizhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, Zhaxiciren, Zhaxisangzhu, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, and G., Zizzi
Subjects: TeV gamma-ray flares – Gamma rays: observations – Galaxy: Crab Nebula [Galaxy]
Abstract: ARGO-YBJ is a full coverage air shower array located at the YangBaJing Cosmic Ray Laboratory (Tibet, P.R. China, 4300 m a.s.l., 606 g/cm2) recording data with a duty cycle 85% and an energy threshold of a few hundred GeV. In this paper the latest results in Gamma-Ray Astronomy are summarized.
Published: 2012

45. Light-component spectrum of the primary cosmic rays in the multi-TeV region measured by the ARGO-YBJ experiment

Author: X. C. Yang, B. Bartoli, Zhenyong Feng, B. Panico, C. Liu, P. R. Shen, Irina James, X. H. Ma, J. K. K. Liu, P. Salvini, G. D'Alí Staiti, P. Vallania, Q. Q. Zhu, P. Pistilli, H. M. Zhang, X. X. Zhou, Giovanni Mancarella, G. Di Sciascio, B. D'Ettorre Piazzoli, P. Creti, R. Santonico, X. X. Li, Y. B. Chen, H. J. Li, Carla Bleve, H. R. Wu, Hongbo Hu, H. Y. Jia, L. Xue, C. F. Feng, Bingwei Xu, C. Y. Wu, A. Surdo, L. Perrone, Hong-peng Lu, C. Q. Liu, Chang-Chun Ning, Zhaoyang Feng, Q. Huang, I. De Mitri, Q. B. Gou, X. Y. Zhang, T. Di Girolamo, Paolo Camarri, T. L. Chen, M. Iacovacci, B. Z. Dai, X. X. Yan, F. R. Zhu, P. F. Zhang, X. J. Bi, Y. Q. Guo, S. Catalanotti, S. W. Cui, S. Z. Chen, Jianli Zhang, P. Bernardini, F. Ruggieri, Cristian Stanescu, P. Branchini, M. Panareo, Zihuang Cao, A. F. Yuan, Carlo Vigorito, B. S. Wang, Longzhou Zhang, Zhaxisangzhu, Haibing Hu, E. Giroletti, Z. G. Yao, S. M. Mari, Antonio Budano, Y. Zhang, Labaciren, D. Martello, M. Zha, C. Cattaneo, A. K. Calabrese Melcarne, Paolo Montini, G. Marsella, R. Iuppa, S. Vernetto, Danzengluobu, X. D. Sheng, J. Y. Li, H.H. He, M. Dattoli, I. Bolognino, M. Y. Liu, Q. Y. Yang, G. Zizzi, X. B. Qu, X. H. Ding, Roberto Cardarelli, Y. H. Tan, A. Pagliaro, G. Liguori, Huaguang Wang, Fudong Shi, S. Mastroianni, Zhaxiciren, Jilong Zhang, Bartoli, B., Bernardini, P., Bi, X. J., Bleve, C., Bolognino, I., Branchini, P., Budano, A., Calabrese Melcarne, A. K., Camarri, P., Cao, Z., Cardarelli, R., Catalanotti, S., Cattaneo, C., Chen, S. Z., Chen, T. L., Chen, Y., Creti, P., Cui, S. W., Dai, B. Z., D'Ali Staiti, G., Danzengluobu, Dattoli, M., De Mitri, I., D'Ettorre Piazzoli, B., Di Girolamo, T., Ding, X. H., Di Sciascio, G., Feng, C. F., Feng, Z., Giroletti, E., Gou, Q. B., Guo, Y. Q., He, H. H., Hu, H., Huang, Q., Iacovacci, M., Iuppa, R., James, I., Jia, H. Y., Labaciren, Li, H. J., Li, J. Y., Li, X. X., Liguori, G., Liu, C., Liu, C. Q., Liu, J., Liu, M. Y., Lu, H., Ma, X. H., Mancarella, G., Mari, S. M., Marsella, G., Martello, D., Mastroianni, S., Montini, P., Ning, C. C., Pagliaro, A., Panareo, M., Panico, B., Perrone, L., Pistilli, P., Qu, X. B., Ruggieri, F., Salvini, P., Santonico, R., Shen, P. R., Sheng, X. D., Shi, F., Stanescu, C., Surdo, A., Tan, Y. H., Vallania, P., Vernetto, S., Vigorito, C., Wang, B., Wang, H., Wu, C. Y., Wu, H. R., Xu, B., Xue, L., Yan, X. X., Yang, Q. Y., Yang, X. C., Yao, Z. G., Yuan, A. F., Zha, M., Zhang, H. M., Zhang, J., Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhaxiciren, Zhaxisangzhu, Zhou, X. X., Zhu, F. R., Zhu, Q. Q., Zizzi, G., Bartoli, B, Bernardini, P, Bi, Xj, Bleve, C, Bolognino, I, Branchini, P, Budano, A, Melcarne, Akc, Camarri, P, Cao, Z, Cardarelli, R, Catalanotti, S, Cattaneo, C, Chen, Sz, Chen, Tl, Chen, Y, Creti, P, Cui, Sw, Dai, Bz, Staiti, Gd, Dattoli, M, De Mitri, I, Piazzoli, Bd, Di Girolamo, T, Ding, Xh, Di Sciascio, G, Feng, Cf, Feng, Zy, Giroletti, E, Gou, Qb, Guo, Yq, He, Hh, Hu, Hb, Huang, Q, Iacovacci, M, Iuppa, R, James, I, Jia, Hy, Li, Hj, Li, Jy, Li, Xx, Liguori, G, Liu, C, Liu, Cq, Liu, J, Liu, My, Lu, H, Ma, Xh, Mancarella, G, Mari, Stefano Maria, Marsella, G, Martello, D, Mastroianni, S, Montini, P, Ning, Cc, Pagliaro, A, Panareo, M, Panico, B, Perrone, L, Pistilli, P, Qu, Xb, Ruggieri, F, Salvini, P, Santonico, R, Shen, Pr, Sheng, Xd, Shi, F, Stanescu, C, Surdo, A, Tan, Yh, Vallania, P, Vernetto, S, Vigorito, C, Wang, B, Wang, H, Wu, Cy, Wu, Hr, Xu, B, Xue, L, Yan, Xx, Yang, Qy, Yang, Xc, Yao, Zg, Yuan, Af, Zha, M, Zhang, Hm, Zhang, Jl, Zhang, L, Zhang, P, Zhang, Xy, Zhang, Y, Zhou, Xx, Zhu, Fr, Zhu, Qq, Bartoli, Bruno, X. J., Bi, A. K. C., Catalanotti, Sergio, Staiti, G. D., Mitri, I. D., D'ETTORRE PIAZZOLI, Benedetto, DI GIROLAMO, Tristano, Sciascio, G. D., Feng, Z. Y., H. H., He, H. B., Hu, Iacovacci, Michele, H. J., Li, J. Y., Li, X. X., Li, X. H., Ma, X. B., Qu, C. Y., Wu, H. R., Wu, Zhang, J. L., B., Bartoli, Bernardini, Paolo, C., Bleve, I., Bolognino, P., Branchini, A., Budano, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, R., Cardarelli, S., Catalanotti, C., Cattaneo, S. Z., Chen, T. L., Chen, Y., Chen, P., Creti, S. W., Cui, B. Z., Dai, G., D’Alı´ Staiti, M., Dattoli, DE MITRI, Ivan, B., D’Ettorre Piazzoli, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, E., Giroletti, Q. B., Gou, Y. Q., Guo, Haibing, Hu, Hongbo, Hu, Q., Huang, M., Iacovacci, R., Iuppa, I., Jame, H. Y., Jia, G., Liguori, C., Liu, C. Q., Liu, J., Liu, M. Y., Liu, H., Lu, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, A., Pagliaro, Panareo, Marco, B., Panico, Perrone, Lorenzo, P., Pistilli, F., Ruggieri, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, B., Wang, H., Wang, B., Xu, L., Xue, X. X., Yan, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, Jilong, Zhang, Jianli, Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, G., Zizzi, Bi, XJ, Calabrese Melcarne, AK, Chen, SZ, Chen, TL, Cui, SW, Dai, BZ, D'ALI'STAITI, G, D’Ettorre Piazzoli, B, Ding, XH, Feng, CF, Feng, ZYa, Feng, ZYo, Gou, QB, Guo, YQ, He, HH, Hu, HBi, Hu, HBo, James, J, Jia, HY, Li, HJ, Li, JY, Li, XX, Liu, CQ, Liu, MY, Ma, XH, Mari, S, Ning, CC, Panareo, P, Qu, XB, Shen, PR, Sheng, XD, Tan, YH, Wu, CY, Wu, HR, Yan, XX, Yang, QY, Yang, XC, Yao, ZG, Yuan, AF, Zhang, HM, Zhang, JLi, Zhang, JLo, Zhang, XY, Zhou, XX, Zhu, FR, Zhu, QQ, and Zizzi, G
Subjects: Extended Air Showers, Cosmic Rays, Gamma Ray sources, Nuclear and High Energy Physics, Proton, TIBET, Astrophysics::High Energy Astrophysical Phenomena, Extensive air shower, chemistry.chemical_element, Cosmic ray, HELIUM SPECTRA, Astrophysics, PROTON, Bayesian method, CASCADES, Spectral line, Settore FIS/05 - Astronomia E Astrofisica, Nuclear magnetic resonance, Cosmic-ray observatory, Helium, Physics, Range (particle radiation), ENERGY-RANGE, BALLOON EXPERIMENT, NUCLEI, Settore FIS/01 - Fisica Sperimentale, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, light component spectrum, chemistry, Energy (signal processing), SYSTEM
Abstract: The ARGO-YBJ experiment detects extensive air showers in a wide energy range by means of a full-coverage detector which is in stable data taking in its full configuration since November 2007 at the YBJ International Cosmic Ray Observatory (4300 m a.s.l., Tibet, People's Republic of China). In this paper the measurement of the light-component spectrum of primary cosmic rays in the energy region $(5\textdiv{}200)\text{ }\text{ }\mathrm{TeV}$ is reported. The method exploited to analyze the experimental data is based on a Bayesian procedure. The measured intensities of the light component are consistent with the recent CREAM results and higher than that obtained adding the proton and helium spectra reported by the RUNJOB experiment.
Published: 2012

46. Long-term monitor of Mrk 421 TeV emission using ARGO-YBJ experiment

Author: B. Bartoli, X. J. Bi, C. Bleve, I. Bolognino, P. Branchini, A. Budano, A. K. Calabrese Melcarne, P. Camarri, Z. Cao, A. Cappa, R. Cardarelli, S. Catalanotti, C. Cattaneo, P. Celio, S. Z. Chen, T. L. Chen, Y. Chen, P. Creti, S. W. Cui, B. Z. Dai, G. D’Alı Staiti, Danzengluobu, M. Dattoli, B. D’Ettorre Piazzoli, T. Di Girolamo, X. H. Ding, G. Di Sciascio, C. F. Feng, Zhaoyang Feng, Zhenyong Feng, F. Galeazzi, P. Galeotti, E. Giroletti, Q. B. Gou, Y. Q. Guo, H. H. He, Haibing Hu, Hongbo Hu, Q. Huang, M. Iacovacci, R. Iuppa, I. James, H. Y. Jia, Labaciren, H. J. Li, J. Y. Li, X. X. Li, G. Liguori, C. Liu, C. Q. Liu, J. Liu, M. Y. Liu, H. Lu, X. H. Ma, S. M. Mari, S. Mastroianni, P. Montini, C. C. Ning, A. Pagliaro, B. Panico, P. Pistilli, X. B. Qu, E. Rossi, F. Ruggieri, P. Salvini, R. Santonico, P. R. Shen, X. D. Sheng, F. Shi, C. Stanescu, A. Surdo, Y. H. Tan, P. Vallania, S. Vernetto, C. Vigorito, B. Wang, H. Wang, C. Y. Wu, H. R. Wu, B. Xu, L. Xue, Y. X. Yan, Q. Y. Yang, X. C. Yang, Z. G. Yao, A. F. Yuan, M. Zha, H. M. Zhang, Jilong Zhang, Jianli Zhang, L. Zhang, P. Zhang, X. Y. Zhang, Y. Zhang, Zhaxiciren, Zhaxisangzhu, X. X. Zhou, F. R. Zhu, Q. Q. Zhu, G. Zizzi, BERNARDINI, Paolo, DE MITRI, Ivan, MANCARELLA, Giovanni, MARSELLA, GIOVANNI, MARTELLO, Daniele, PANAREO, Marco, PERRONE, Lorenzo, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, I., Bolognino, P., Branchini, A., Budano, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, A., Cappa, R., Cardarelli, S., Catalanotti, C., Cattaneo, P., Celio, S. Z., Chen, T. L., Chen, Y., Chen, P., Creti, S. W., Cui, B. Z., Dai, G., D’Alı Staiti, Danzengluobu, M., Dattoli, DE MITRI, Ivan, B., D’Ettorre Piazzoli, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, F., Galeazzi, P., Galeotti, E., Giroletti, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Hu, Hongbo, Hu, Q., Huang, M., Iacovacci, R., Iuppa, I., Jame, H. Y., Jia, Labaciren, H. J., Li, J. Y., Li, X. X., Li, G., Liguori, C., Liu, C. Q., Liu, J., Liu, M. Y., Liu, H., Lu, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, A., Pagliaro, Panareo, Marco, B., Panico, Perrone, Lorenzo, P., Pistilli, X. B., Qu, E., Rossi, F., Ruggieri, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, B., Wang, H., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, Y. X., Yan, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, Jilong, Zhang, Jianli, Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, Zhaxiciren, Zhaxisangzhu, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, and G., Zizzi
Subjects: gamma ray observations, Markarian 421, BL Lacertae object
Abstract: ARGO-YBJ is an air shower detector array with a fully covered layer of Resistive Plate Chambers. It is operated with a high duty cycle and a large field of view. It monitors continuously the northern sky at energies above 0.3 TeV. In this paper, we report a long-term monitoring of Mrk 421 over the period from November 2007 to February 2010. Meanwhile, this source was observed by the satellite-borne experiments RXTE and Swift in the X-ray band. Mrk 421 was very active especially in the first half of 2008. Many flares are observed in both X-ray and gamma-ray bands simultaneously. The gamma-ray flux observed by ARGO-YBJ has a clear correlation with the X-ray flux. No lag longer than 1 day between the X-ray and gamma-ray photons is found. The evolution of the spectral energy distribution is investigated by measuring indices at four different flux levels. Hardening of the spectra is observed in both X-ray and gamma-ray bands. The gamma-ray flux increases quadratically with the simultaneously measured X-ray flux. All these observational results strongly favor the synchrotron self-Compton process as the underlying radiative mechanism.
Published: 2011

47. Observation of the cosmic ray moon shadowing effect with the ARGO-YBJ experiment

Author: B. Bartoli, P. Bernardini, X. J. Bi, C. Bleve, I. Bolognino, P. Branchini, A. Budano, A. K. Calabrese Melcarne, P. Camarri, Z. Cao, R. Cardarelli, S. Catalanotti, C. Cattaneo, P. Celio, S. Z. Chen, T. L. Chen, Y. Chen, P. Creti, S. W. Cui, B. Z. Dai, G. D’Alí Staiti, null Danzengluobu, M. Dattoli, I. De Mitri, B. D’Ettorre Piazzoli, T. Di Girolamo, X. H. Ding, G. Di Sciascio, C. F. Feng, Zhaoyang Feng, Zhenyong Feng, F. Galeazzi, E. Giroletti, Q. B. Gou, Y. Q. Guo, H. H. He, Haibing Hu, Hongbo Hu, Q. Huang, M. Iacovacci, R. Iuppa, I. James, H. Y. Jia, null Labaciren, H. J. Li, J. Y. Li, X. X. Li, G. Liguori, C. Liu, C. Q. Liu, J. Liu, M. Y. Liu, H. Lu, X. H. Ma, G. Mancarella, S. M. Mari, G. Marsella, D. Martello, S. Mastroianni, P. Montini, C. C. Ning, A. Pagliaro, M. Panareo, B. Panico, L. Perrone, P. Pistilli, X. B. Qu, E. Rossi, F. Ruggieri, P. Salvini, R. Santonico, P. R. Shen, X. D. Sheng, F. Shi, C. Stanescu, A. Surdo, Y. H. Tan, P. Vallania, S. Vernetto, C. Vigorito, B. Wang, H. Wang, C. Y. Wu, H. R. Wu, B. Xu, L. Xue, Y. X. Yan, Q. Y. Yang, X. C. Yang, Z. G. Yao, A. F. Yuan, M. Zha, H. M. Zhang, Jilong Zhang, Jianli Zhang, L. Zhang, P. Zhang, X. Y. Zhang, Y. Zhang, null Zhaxiciren, null Zhaxisangzhu, X. X. Zhou, F. R. Zhu, Q. Q. Zhu, G. Zizzi, Bartoli, B, Bernardini, P, Bi, Xj, Bleve, C, Bolognino, I, Branchini, P, Budano, A, Melcarne, Akc, Camarri, P, Cao, Z, Cardarelli, R, Catalanotti, S, Cattaneo, C, Celio, P, Chen, Sz, Chen, Tl, Chen, Y, Creti, P, Cui, Sw, Dai, Bz, Staiti, Gd, Danzengluobu, Dattoli, M, De Mitri, I, Piazzoli, Bd, Di Girolamo, T, Ding, Xh, Di Sciascio, G, Feng, Cf, Feng, Zy, Galeazzi, F, Giroletti, E, Gou, Qb, Guo, Yq, He, Hh, Hu, Hb, Huang, Q, Iacovacci, M, Iuppa, R, James, I, Jia, Hy, Labaciren, Li, Hj, Li, Jy, Li, Xx, Liguori, G, Liu, C, Liu, Cq, Liu, J, Liu, My, Lu, H, Ma, Xh, Mancarella, G, Mari, Stefano Maria, Marsella, G, Martello, D, Mastroianni, S, Montini, P, Ning, Cc, Pagliaro, A, Panareo, M, Panico, B, Perrone, L, Pistilli, P, Qu, Xb, Rossi, E, Ruggieri, F, Salvini, P, Santonico, R, Shen, Pr, Sheng, Xd, Shi, F, Stanescu, C, Surdo, A, Tan, Yh, Vallania, P, Vernetto, S, Vigorito, C, Wang, B, Wang, H, Wu, Cy, Wu, Hr, Xu, B, Xue, L, Yan, Yx, Yang, Qy, Yang, Xc, Yao, Zg, Yuan, Af, Zha, M, Zhang, Hm, Zhang, Jl, Zhang, L, Zhang, P, Zhang, Xy, Zhang, Y, Zhaxiciren, Zhaxisangzhu, Zhou, Xx, Zhu, Fr, Zhu, Qq, Zizzi, G., Bartoli, Bruno, Catalanotti, Sergio, D'ETTORRE PIAZZOLI, Benedetto, DI GIROLAMO, Tristano, Iacovacci, Michele, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, I., Bolognino, P., Branchini, A., Budano, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, R., Cardarelli, S., Catalanotti, C., Cattaneo, P., Celio, S. Z., Chen, T. L., Chen, Y., Chen, P., Creti, S. W., Cui, B. Z., Dai, G., D’Alı´ Staiti, M., Dattoli, DE MITRI, Ivan, B., D’Ettorre Piazzoli, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, F., Galeazzi, E., Giroletti, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Hu, Hongbo, Hu, Q., Huang, M., Iacovacci, R., Iuppa, I., Jame, H. Y., Jia, H. J., Li, J. Y., Li, X. X., Li, G., Liguori, C., Liu, C. Q., Liu, J., Liu, M. Y., Liu, H., Lu, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, A., Pagliaro, Panareo, Marco, B., Panico, Perrone, Lorenzo, P., Pistilli, X. B., Qu, E., Rossi, F., Ruggieri, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, B., Wang, H., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, Y. X., Yan, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, Jilong, Zhang, Jianli, Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, G., Zizzi, D'Ali' Staiti, G, Bi, XJ, Calabrese Melcarne, AK, Chen, SZ, Chen, TL, Cui, SW, Dai, BZ, D’Alı Staiti, G, D’Ettorre Piazzoli, B, Ding, XH, Feng, CF, Feng, ZYa, Feng, ZYo, Gou, QB, Guo, YQ, He, HH, Hu, HBi, Hu, HBo, Jia, HY, Li, HJ, Li, JY, Li, XX, Liu, CQ, Liu, MY, Ma, XH, Mari, SM, Ning, CC, Qu, XB, Shen, PR, Sheng, XD, Tan, YH, Wu, CY, Wu, HR, Yan, YX, Yang, QY, Yang, XC, Yao, ZG, Yuan, AF, Zhang, HM, Zhang, JLi, Zhang, JLo, Zhang, XY, Zhaxiciren, Zhaxisangzhu, Zhou, XX, Zhu, FR, Zhu, QQ, and Zizzi, G
Subjects: Point spread function, Nuclear and High Energy Physics, Cosmic Rays, Gamma Astronomy, Extended Air Showers, Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, Cosmic ray, Astrophysics, 01 natural sciences, Standard deviation, Physics::Geophysics, Raggi cosmici, Settore FIS/05 - Astronomia E Astrofisica, geomagnetic field, 0103 physical sciences, 010303 astronomy & astrophysics, Physics, 010308 nuclear & particles physics, Ombra della luna, Apparati di sciame, Detector, Settore FIS/01 - Fisica Sperimentale, Moon shadow, Astronomy, Magnetic field, Earth's magnetic field, Air shower, 13. Climate action, Physics::Space Physics
Abstract: Cosmic rays are hampered by the Moon and a deficit in its direction is expected (the so-called Moon shadow). The Moon shadow is an important tool to determine the performance of an air shower array. Indeed, the westward displacement of the shadow center, due to the bending effect of the geomagnetic field on the propagation of cosmic rays, allows the setting of the absolute rigidity scale of the primary particles inducing the showers recorded by the detector. In addition, the shape of the shadow permits to determine the detector point spread function, while the position of the deficit at high energies allows the evaluation of its absolute pointing accuracy. In this paper we present the observation of the cosmic ray Moon shadowing effect carried out by the ARGO-YBJ experiment in the multi-TeV energy region with high statistical significance (55 standard deviations). By means of an accurate Monte Carlo simulation of the cosmic rays propagation in the Earth-Moon system, we have studied separately the effect of the geomagnetic field and of the detector point spread function on the observed shadow. The angular resolution as a function of the particle multiplicity and the pointing accuracy have been obtained. The primary energy of detected showers has been estimated by measuring the westward displacement as a function of the particle multiplicity, thus calibrating the relation between shower size and cosmic ray energy. The stability of the detector on a monthly basis has been checked by monitoring the position and the deficit of the Moon shadow. Finally, we have studied with high statistical accuracy the shadowing effect in the day/’’night’’ time looking for possible effect induced by the solar wind.
Published: 2011

48. Mean Interplanetary Magnetic Field Measurement Using the ARGO-YBJ Experiment

Author: X. X. Li, Zhenyong Feng, L. Zhang, B. D'Ettorre Piazzoli, L. Xue, G. Mancarella, Q. B. Gou, A. Cappa, M. Zha, F. R. Zhu, M. Panareo, B. Z. Dai, M. Iacovacci, Piero Vallania, P. Creti, Danzengluobu, F. Ruggieri, A. K. Calabrese Melcarne, L. Perrone, P. Salvini, R. Cardarelli, G. Marsella, Q. Q. Zhu, Y. Q. Guo, P. Branchini, H. Y. Jia, G. Aielli, R. Santonico, H. H. He, C. Bacci, S. M. Mari, Zhengguo Cao, X. C. Yang, B. S. Wang, A. Pagliaro, Q. Y. Yang, Bingwei Xu, P. F. Zhang, E. Giroletti, Severino Angelo Maria Bussino, S. W. Cui, Hongbo Hu, A. Surdo, C. F. Feng, X. J. Bi, H. R. Wu, I. De Mitri, X. R. Meng, C. Stanescu, Irina James, A. F. Yuan, Chang-Chun Ning, Zhaoyang Feng, J. Y. Li, Jilong Zhang, T. Di Girolamo, F. Shi, Jianli Zhang, T. L. Chen, H. M. Zhang, G. Di Sciascio, Carlo Vigorito, P. Celio, C. Y. Wu, M. Y. Liu, M. De Vincenzi, Haibing Hu, R. Gargana, I. Bolognino, B. Bartoli, H. J. Li, X. D. Sheng, C. Bleve, Y. B. Chen, S. Z. Chen, L. Saggese, Y. Zhang, B. Liberti, Paolo Bernardini, D. Martello, X. B. Qu, X. H. Ding, Labaciren, J. K. K. Liu, P. Pistilli, X. X. Zhou, G. D'Alí Staiti, Y. H. Tan, P. Galeotti, Q. Huang, X. Y. Zhang, C. Liu, X. H. Ma, G. Liguori, C. X. Liu, Zhaxisangzhu, S. Catalanotti, Z. G. Yao, Y. X. Yan, E. Rossi, M. Dattoli, H. Lu, Paolo Montini, R. Iuppa, and G. Zizzi, P. Camarri, H. W. Wang, S. Vernetto, F. Galeazzi, A. Budano, S. Mastroianni, C. Cattaneo, P. R. Shen, Bartoli, Bruno, Catalanotti, Sergio, D'ETTORRE PIAZZOLI, Benedetto, DI GIROLAMO, Tristano, Iacovacci, Michele, Aielli, G, Bacci, C, Bartoli, B, Bernardini, P, Bi, XJ, Bleve, C, Bolognino, I, Branchini, P, Budano, A, Bussino, S, Calabrese Melcarne, AK, Camarri, P, Cao, Z, Cappa, A, Cardarelli, R, Catalanotti, S, Cattaneo, C, Celio, P, Chen, SZ, Chen, TL, Chen, Y, Creti, P, Cui, SW, Dai, BZ, D'Ali Staiti, G, Danzengluobu, Dattoli, M, De Mitri, I, D'Ettorre Piazzoli, B, De Vincenzi, M, Di Girolamo, T, Ding, XH, Di Sciascio, G, Feng, CF, Feng, ZYa, Feng, ZYo, Galeazzi, F, Galeotti, P, Gargana, R, Giroletti, E, Gou, QB, Guo, YQ, He, HH, Hu, HaB, Hu, HoB, Huang, Q, Iacovacci, M, Iuppa, R, James, I, Jia, HY, Labaciren, Li, HJ, Li, JY, Li, XX, Liberti, B, Liguori, G, Liu, C, Liu, CQ, Liu, MY, Liu, J, Lu, H, Ma, XH, Mancarella, G, Mari, SM, Marsella, G, Martello, D, Mastroianni, S, Meng, XR, Montini, P, Ning, CC, Pagliaro, A, Panareo, M, Perrone, L, Pistilli, P, Qu XB, Rossi, E, Ruggieri, F, Saggese, L, Salvini, P, Santonico, R, Shen, PR, Sheng, XD, Shi, F, Stanescu, C, Surdo, A, Tan, YH, Vallania, P, Vernetto, S, Vigorito, C, Wang, B, Wang, H, Wu, CY, Wu, HR, Xu, B, Xue, L, Yan, YX, Yang, QY, Yang, XC, Yao, ZG, Yuan, AF, Zha, M, Zhang, HM, Zhang, JLi, Zhang, JLo, Zhang, L, Zhang, P, Zhang, XY, Zhang, Y, Zhaxisangzhu, Zhou, XX, Zhu, FR, Zhu, QQ, Zizzi, G, G., Aielli, C., Bacci, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, I., Bolognino, P., Branchini, A., Budano, S., Bussino, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, A., Cappa, R., Cardarelli, S., Catalanotti, C., Cattaneo, P., Celio, S. Z., Chen, T. L., Chen, Y., Chen, P., Creti, S. W., Cui, B. Z., Dai, G., D'Alí Staiti, M., Dattoli, DE MITRI, Ivan, B., D'Ettorre Piazzoli, M., De Vincenzi, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, F., Galeazzi, P., Galeotti, R., Gargana, E., Giroletti, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Hu, Hongbo, Hu, Q., Huang, M., Iacovacci, R., Iuppa, I., Jame, H. Y., Jia, H. J., Li, J. Y., Li, X. X., Li, B., Liberti, G., Liguori, C., Liu, C. Q., Liu, M. Y., Liu, J., Liu, H., Lu, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, X. R., Meng, P., Montini, C. C., Ning, A., Pagliaro, Panareo, Marco, Perrone, Lorenzo, P., Pistilli, X. B., Qu, E., Rossi, F., Ruggieri, L., Saggese, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, B., Wang, H., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, Y. X., Yan, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, Jilong, Zhang, Jianli, Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, G., Zizzi, Bi, Xj, Bussino, Severino Angelo Maria, Melcarne, Akc, Chen, Sz, Chen, Tl, Cui, Sw, Dai, Bz, Staiti, Gd, Piazzoli, Bd, DE VINCENZI, Mario, Ding, Xh, Feng, Cf, Feng, Zy, Gou, Qb, Guo, Yq, He, Hh, Hu, Hb, Jia, Hy, Li, Hj, Li, Jy, Li, Xx, Liu, Cq, Liu, My, Ma, Xh, Mari, Stefano Maria, Meng, Xr, Ning, Cc, Qu, Xb, Shen, Pr, Sheng, Xd, Tan, Yh, Wu, Cy, Wu, Hr, Yan, Yx, Yang, Qy, Yang, Xc, Yao, Zg, Yuan, Af, Zhang, Hm, Zhang, Jl, Zhang, Xy, Zhou, Xx, Zhu, Fr, Zhu, Qq, and Zizzi, G.
Subjects: Solar System, Field (physics), media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, magnetic field, Cosmic ray, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Settore FIS/05 - Astronomia E Astrofisica, Shadow, Astrophysics::Solar and Stellar Astrophysics, Interplanetary magnetic field, cosmic ray, Solar and Stellar Astrophysics (astro-ph.SR), media_common, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Settore FIS/01 - Fisica Sperimentale, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, Cosmic Rays, Gamma Sources, Extended Air Showers, Solar wind, Magnetic field, Solar wind, Astrophysics - Solar and Stellar Astrophysics, solar wind, Space and Planetary Science, Sky, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: The sun blocks cosmic ray particles from outside the solar system, forming a detectable shadow in the sky map of cosmic rays detected by the ARGO-YBJ experiment in Tibet. Because the cosmic ray particles are positive charged, the magnetic field between the sun and the earth deflects them from straight trajectories and results in a shift of the shadow from the true location of the sun. Here we show that the shift measures the intensity of the field which is transported by the solar wind from the sun to the earth., Comment: 6 papges,3 figures
Published: 2011
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49. Early warning for VHE gamma-ray flares with the ARGO-YBJ detector

Author: Y. Q. Guo, B. D'Ettorre Piazzoli, Haibing Hu, H. J. Li, H. R. Wu, C. Bleve, Y. Zhang, L. Xue, X. B. Qu, D. Martello, C. Stanescu, Chang-Chun Ning, B. Bartoli, R. Santonico, Zhaoyang Feng, X. H. Ding, Hong-peng Lu, Jilong Zhang, F. Galeazzi, B. Z. Dai, F. R. Zhu, Y. X. Yan, L. Zhang, F. Ruggieri, Piero Vallania, B. Panico, F. Shi, Y. H. Tan, Zhenyong Feng, C. Liu, P. Branchini, Danzengluobu, X. C. Yang, M. Dattoli, A. K. Calabrese Melcarne, Hongbo Hu, P. Pistilli, X. X. Zhou, C. Y. Wu, M. Iacovacci, M. Zha, X. H. Ma, A. Surdo, R. Cardarelli, C. F. Feng, M. Panareo, J. K. K. Liu, A. Cappa, G. Marsella, Bingwei Xu, E. Giroletti, X. Y. Zhang, Zhiguo Yao, H. H. He, Q. Q. Zhu, Q. B. Gou, A. F. Yuan, Minghui Liu, P. Creti, P. Galeotti, A. Budano, P. Salvini, Labaciren, Jianli Zhang, A. Pagliaro, I. De Mitri, X. D. Sheng, P. R. Shen, Paolo Bernardini, S. Mastroianni, T. Di Girolamo, T. L. Chen, H. M. Zhang, P. Celio, Q. Huang, Q. Y. Yang, I. Bolognino, G. Liguori, Zhaxiciren, G. Zizzi, J. Y. Li, G. Di Sciascio, C. X. Liu, H. W. Wang, G. D'Alí Staiti, Y. B. Chen, H. Y. Jia, Carlo Vigorito, Irina James, G. Mancarella, Paolo Camarri, L. Perrone, Zihuang Cao, X. X. Li, B. S. Wang, Zhaxisangzhu, S. M. Mari, P. F. Zhang, X. J. Bi, S. Z. Chen, C. Cattaneo, E. Rossi, Paolo Montini, R. Iuppa, S. Vernetto, S. Catalanotti, S. W. Cui, Bartoli, B, Bernardini, P, Bi, XJ, Bleve, C, Bolognino, I, Branchini, P, Budano, A, Calabrese Melcarne, AK, Camarri, P, Cao, Z, Cappa, A, Cardarelli, R, Catalanotti, S, Cattaneo, C, Celio, P, Chen, SZ, Chen, TL, Chen, Y, Creti, P, Cui, SW, Dai, BZ, D’Ali' Staiti, G, Danzengluobu, Dattoli, M, De Mitri, I, D’Ettorre Piazzoli, B, Di Girolamo, T, Ding, XH, Di Sciascio, G, Feng, CF, Feng, ZYa, Feng, ZYo, Galeazzi, F, Galeotti, P, Giroletti, E, Gou, QB, Guo, YQ, He, HH, Hu, HBa, Hu, HBo, Huang, Q, Iacovacci, M, Iuppa, R, James, I, Jia, HY, Labaciren, Li, HJ, Li, JY, Li, XX, Liguori, G, Liu, C, Liu, CQ, Liu, J, Liu, MY, Lu, H, Ma, XH, Mancarella, G, Mari, SM, Marsella, G, Martello, D, Mastroianni, S, Montini, P, Ning, CC, Pagliaro, A, Panareo, M, Panico, B, Perrone, L, Pistilli, P, Qu, XB, Rossi, E, Ruggieri, F, Salvini, P, Santonico, R, Shen, PR, Sheng, XD, Shi, F, Stanescu, C, Surdo, A, Tan, YH, Vallania, P, Vernetto, S, Vigorito, C, Wang, B, Wang, H, Wu, CY, Wu, HR, Xu B, Xue, L, Yan, YX, Yang, QY, Yang, XC, Yao, ZG, Yuan, AF, Zha, M, Zhang, HM, Zhang, JLo, Zhang, JLi, Zhang, L, Zhang, P, Zhang, XY, Zhang, Y, Zhaxiciren, Zhaxisangzhu, Zhou, XX, Zhu, FR, Zhu, QQ, Zizzi, G, Bartoli, Bruno, Catalanotti, Sergio, D'ETTORRE PIAZZOLI, Benedetto, DI GIROLAMO, Tristano, Iacovacci, Michele, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, I., Bolognino, P., Branchini, A., Budano, A. K., Calabrese Melcarne, P., Camarri, Z., Cao, A., Cappa, R., Cardarelli, S., Catalanotti, C., Cattaneo, P., Celio, S. Z., Chen, T. L., Chen, Y., Chen, P., Creti, S. W., Cui, B. Z., Dai, G., D’Alı´staiti, M., Dattoli, DE MITRI, Ivan, B., D’Ettorre Piazzoli, T., Di Girolamo, X. H., Ding, G., Di Sciascio, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, F., Galeazzi, P., Galeotti, E., Giroletti, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Huo, Hongbo, Hue, Q., Huang, M., Iacovacci, R., Iuppa, I., Jame, H. Y., Jia, H. J., Li, J. Y., Li, X. X., Li, G., Liguori, C., Liu, C. Q., Liu, J., Liu, M. Y., Liu, H., Lu, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, P., Montini, C. C., Ning, A., Pagliaro, Panareo, Marco, B., Panico, Perrone, Lorenzo, P., Pistilli, X. B., Qu, E., Rossi, F., Ruggieri, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, B., Wang, H., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, Y. X., Yan, Q. Y., Yang, X. C., Yang, Z. G., Yao, A. F., Yuan, M., Zha, H. M., Zhang, Jilongzhang, Jianlizhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, Zhaxiciren, Zhaxisangzhu, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, G., Zizzi, Barton, B, Bi, Xj, Melcarne, Akc, Chen, Sz, Chen, Tl, Cui, Sw, Dai, Bz, Staiti, Gd, Piazzoli, Bd, Ding, Xh, Feng, Cf, Feng, Zy, Gou, Qb, Guo, Yq, He, Hh, Hu, Hb, Ilacovacci, M, Jia, Hy, Li, Hj, Li, Jy, Li, Xx, Liu, Cq, Liu, My, Ma, Xh, Mari, Stefano Maria, Ning, Cc, Qu, Xb, Santonicoi, R, Shen, Pr, Sheng, Xd, Tan, Yh, Wu, Cy, Wu, Hr, Xu, B, Yan, Yx, Yang, Qy, Yang, Xc, Yao, Zg, Yuan, Af, Zhang, Hm, Zhang, Jl, Zhang, Xy, Zhou, Xx, Zhu, Fr, Zhu, Qq, and Zizzi, G.
Subjects: Wide field of view, Nuclear and High Energy Physics, Monitoring, Astrophysics::High Energy Astrophysical Phenomena, ARGO-YBJ, Flaring phenomenon, VHE extragalactic source, Astrophysics, Settore FIS/05 - Astronomia E Astrofisica, Instrumentation, Sorgenti VHE extragalattiche, Argo, Cherenkov radiation, Physics, Fenomeni transienti, Warning system, Detector, Settore FIS/01 - Fisica Sperimentale, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Monitoring Flaring Phenomenon, Astronomy, Wide field, Duty cycle, Ampio campo di vista, Flaring phenomena, VHE extragalactic sources, Gamma Ray Bursts, Large Field of view telescope, ARGO-YBJ, Gamma-ray burst
Abstract: Detecting and monitoring emissions from flaring gamma-ray sources in the very-high-energy (VHE, > 100 GeV) band is a very important topic in gamma-ray astronomy. The ARGO-YBJ detector is characterized by a high duty cycle and a wide field of view. Therefore, it is particularly capable of detecting flares from extragalactic objects. Based on fast reconstruction and analysis, real-time monitoring of 33 selected VHE extragalactic sources is implemented. Flares exceeding a specific threshold are reported timely, hence enabling the follow-up observation of these objects using more sensitive detectors, such as Cherenkov telescopes. (C) 2011 Elsevier B.V. All rights reserved.
Published: 2011

50. Gamma-ray flares from Mrk421 in 2008 observed with the ARGO-YBJ experiment

Author: G. AIELLI, C. BACCI, B. BARTOLI, X. J. BI, C. BLEVE, P. BRANCHINI, A. BUDANO, S. BUSSINO, A. K. CALABRESE MELCARNE, P. CAMARRI, Z. CAO, A. CAPPA, R. CARDARELLI, S. CATALANOTTI, C. CATTANEO, P. CELIO, S. Z. CHEN, Y. CHEN, N. CHENG, P. CRETI, S. W. CUI, B. Z. DAI, G. D’ALÍ STAITI, DANZENGLUOBU, M. DATTOLI, B. D’ETTORRE PIAZZOLI, M. DE VINCENZI, T. DI GIROLAMO, X. H. DING, G. DI SCIASCIO, C. F. FENG, ZHAOYANG FENG, ZHENYONG FENG, F. GALEAZZI, P. GALEOTTI, R. GARGANA, Q. B. GOU, Y. Q. GUO, H. H. HE, HAIBING HU, HONGBO HU, Q. HUANG, M. IACOVACCI, R. IUPPA, I. JAMES, H. Y. JIA, LABACIREN, H. J. LI, J. Y. LI, X. X. LI, B. LIBERTI, G. LIGUORI, C. LIU, C. Q. LIU, M. Y. LIU, J. LIU, H. LU, X. H. MA, S. M. MARI, S. MASTROIANNI, X. R. MENG, P. MONTINI, C. C. NING, A. PAGLIARO, P. PISTILLI, X. B. QU, E. ROSSI, F. RUGGIERI, L. SAGGESE, P. SALVINI, R. SANTONICO, P. R. SHEN, X. D. SHENG, F. SHI, C. STANESCU, A. SURDO, Y. H. TAN, P. VALLANIA, S. VERNETTO, C. VIGORITO, B. WANG, H. WANG, C. Y. WU, H. R. WU, B. XU, L. XUE, Y. X. YAN, Q. Y. YANG, X. C. YANG, A. F. YUAN, M. ZHA, H. M. ZHANG, JILONG ZHANG, JIANLI ZHANG, L. ZHANG, P. ZHANG, X. Y. ZHANG, Y. ZHANG, ZHAXISANGZHU, X. X. ZHOU, F. R. ZHU, Q. Q. ZHU, G. ZIZZI, BERNARDINI, Paolo, DE MITRI, Ivan, MANCARELLA, Giovanni, MARSELLA, GIOVANNI, MARTELLO, Daniele, PANAREO, Marco, PERRONE, Lorenzo, G., Aielli, C., Bacci, B., Bartoli, Bernardini, Paolo, X. J., Bi, C., Bleve, P., Branchini, A., Budano, S., Bussino, A. K., CALABRESE MELCARNE, P., Camarri, Z., Cao, A., Cappa, R., Cardarelli, S., Catalanotti, C., Cattaneo, P., Celio, S. Z., Chen, Y., Chen, N., Cheng, P., Creti, S. W., Cui, B. Z., Dai, G., D’ALÍ STAITI, Danzengluobu, M., Dattoli, DE MITRI, Ivan, B., D’ETTORRE PIAZZOLI, M., DE VINCENZI, T., DI GIROLAMO, X. H., Ding, G., DI SCIASCIO, C. F., Feng, Zhaoyang, Feng, Zhenyong, Feng, F., Galeazzi, P., Galeotti, R., Gargana, Q. B., Gou, Y. Q., Guo, H. H., He, Haibing, Hu, Hongbo, Hu, Q., Huang, M., Iacovacci, R., Iuppa, I., Jame, H. Y., Jia, Labaciren, H. J., Li, J. Y., Li, X. X., Li, B., Liberti, G., Liguori, C., Liu, C. Q., Liu, M. Y., Liu, J., Liu, H., Lu, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, S., Mastroianni, X. R., Meng, P., Montini, C. C., Ning, A., Pagliaro, Panareo, Marco, Perrone, Lorenzo, P., Pistilli, X. B., Qu, E., Rossi, F., Ruggieri, L., Saggese, P., Salvini, R., Santonico, P. R., Shen, X. D., Sheng, F., Shi, C., Stanescu, A., Surdo, Y. H., Tan, P., Vallania, S., Vernetto, C., Vigorito, B., Wang, H., Wang, C. Y., Wu, H. R., Wu, B., Xu, L., Xue, Y. X., Yan, Q. Y., Yang, X. C., Yang, A. F., Yuan, M., Zha, H. M., Zhang, Jilong, Zhang, Jianli, Zhang, L., Zhang, P., Zhang, X. Y., Zhang, Y., Zhang, Zhaxisangzhu, X. X., Zhou, F. R., Zhu, Q. Q., Zhu, and G., Zizzi
Subjects: TeV gamma-ray flares – Gamma rays: observations [Mrk421 – Galaxy]
Abstract: In 2008, the blazar Mrk421 entered in a very active phase and was one of the brightest sources in the sky at TeV energies, showing strong and frequent flaring. We searched for gamma-ray emission at energies E>0.8 TeV during the whole 2008 with the ARGO-YBJ experiment, a full coverage air shower detector located at Yangbajing (4300 m a.s.l., Tibet, P.R. China). The observed signal is not constant and in correlation with X-ray measurements. The average emission, during the active period of the source, was about twice the Crab Nebula level. This paper concentrates on 2008 June when the Mrk421 flaring activity has been studied from optical to 100 MeV gamma rays, and only partially up to TeV energies, since the moonlight hampered the Cherenkov telescope observations after 8 June. Our data complete these observations, with the detection of a second flare of intensity of about 7 Crab units on June 11-13, with a statistical significance of 4.2 standard deviations. The observed flux is consistent with a prediction made in the framework of the Synchrotron Self-Compton model, in which the flare is caused by a rapid acceleration of leptons in the jet.
Published: 2010

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