Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A
Creators: name: The LHAASO Collaboration
name: Cao, Zhen
name: Aharonian, F.
name: An, Q.
name: Axikegu, A.
name: Bai, Y. X.
name: Bao, Y. W.
name: Bastieri, D.
name: Bi, X. J.
name: Bi, Y. J.
name: Cai, J. T.
name: Cao, Q.
name: Cao, W. Y.
name: Cao, Zhe
name: Chang, J.
name: Chang, J. F.
name: Chen, A. M.
name: Chen, E. S.
name: Chen, Liang
name: Chen, Lin
name: Chen, Long
name: Chen, M. J.
name: Chen, M. L.
name: Chen, Q. H.
name: Chen, S. H.
name: Chen, S. Z.
name: Chen, T. L.
name: Chen, Y.
name: Cheng, N.
name: Cheng, Y. D.
name: Cui, M. Y.
name: Cui, S. W.
name: Cui, X. H.
name: Cui, Y. D.
name: Dai, B. Z.
name: Dai, H. L.
name: Dai, Z. G.
name: Danzengluobu
name: della Volpe, D.
name: Dong, X. Q.
name: Duan, K. K.
name: Fan, J. H.
name: Fan, Y. Z.
name: Fang, J.
name: Fang, K.
name: Feng, C. F.
name: Feng, L.
name: Feng, S. H.
name: Feng, X. T.
name: Feng, Y. L.
name: Gabici, S.
name: Gao, B.
name: Gao, C. D.
name: Gao, L. Q.
name: Gao, Q.
name: Gao, W.
name: Gao, W. K.
name: Ge, M. M.
name: Geng, L. S.
name: Giacinti, G.
name: Gong, G. H.
name: Gou, Q. B.
name: Gu, M. H.
name: Guo, F. L.
name: Guo, X. L.
name: Guo, Y. Q.
name: Guo, Y. Y.
name: Han, Y. A.
name: He, H. H.
name: He, H. N.
name: He, J. Y.
name: He, X. B.
name: He, Y.
name: Heller, M.
name: Hor, Y. K.
name: Hou, B. W.
name: Hou, C.
name: Hou, X.
name: Hu, H. B.
name: Hu, Q.
name: Hu, S. C.
name: Huang, D. H.
name: Huang, T. Q.
name: Huang, W. J.
name: Huang, X. T.
name: Huang, X. Y.
name: Huang, Y.
name: Huang, Z. C.
name: Ji, X. L.
name: Jia, H. Y.
name: Jia, K.
name: Jiang, K.
name: Jiang, X. W.
name: Jiang, Z. J.
name: Jin, M.
name: Kang, M. M.
name: Ke, T.
name: Kuleshov, D.
name: Kurinov, K.
name: Li, B. B.
name: Li, Cheng
name: Li, Cong
name: Li, D.
name: Li, F.
name: Li, H. B.
name: Li, H. C.
name: Li, H. Y.
name: Li, J.
name: Li, Jian
name: Li, Jie
name: Li, K.
name: Li, W. L.
name: Li, W. L.
name: Li, X. R.
name: Li, Xin
name: Li, Y. Z.
name: Li, Zhe
name: Li, Zhuo
name: Liang, E. W.
name: Liang, Y. F.
name: Lin, S. J.
name: Liu, B.
name: Liu, C.
name: Liu, D.
name: Liu, H.
name: Liu, H. D.
name: Liu, J.
name: Liu, J. L.
name: Liu, J. Y.
name: Liu, M. Y.
name: Liu, R. Y.
name: Liu, S. M.
name: Liu, W.
name: Liu, Y.
name: Liu, Y. N.
name: Lu, R.
name: Luo, Q.
name: Lv, H. K.
name: Ma, B. Q.
name: Ma, L. L.
name: Ma, X. H.
name: Mao, J. R.
name: Min, Z.
name: Mitthumsiri, W.
name: Mu, H. J.
name: Nan, Y. C.
name: Neronov, A.
name: Ou, Z. W.
name: Pang, B. Y.
name: Pattarakijwanich, P.
name: Pei, Z. Y.
name: Qi, M. Y.
name: Qi, Y. Q.
name: Qiao, B. Q.
name: Qin, J. J.
name: Ruffolo, D.
name: Sáiz, A.
name: Semikoz, D.
name: Shao, C. Y.
name: Shao, L.
name: Shchegolev, O.
name: Sheng, X. D.
name: Shu, F. W.
name: Song, H. C.
name: Stenkin, Yu. V.
name: Stepanov, V.
name: Su, Y.
name: Sun, Q. N.
name: Sun, X. N.
name: Sun, Z. B.
name: Tam, P. H. T.
name: Tang, Q. W.
name: Tang, Z. B.
name: Tian, W. W.
name: Wang, C.
name: Wang, C. B.
name: Wang, G. W.
name: Wang, H. G.
name: Wang, H. H.
name: Wang, J. C.
name: Wang, K.
name: Wang, L. P.
name: Wang, L. Y.
name: Wang, P. H.
name: Wang, R.
name: Wang, W.
name: Wang, X. G.
name: Wang, X. Y.
name: Wang, Y.
name: Wang, Y. D.
name: Wang, Y. J.
name: Wang, Z. H.
name: Wang, Z. X.
name: Wang, Zhen
name: Wang, Zheng
name: Wei, D. M.
name: Wei, J. J.
name: Wei, Y. J.
name: Wen, T.
name: Wu, C. Y.
name: Wu, H. R.
name: Wu, S.
name: Wu, X. F.
name: Wu, Y. S.
name: Xi, S. Q.
name: Xia, J.
name: Xia, J. J.
name: Xiang, G. M.
name: Xiao, D. X.
name: Xiao, G.
name: Xin, G. G.
name: Xin, Y. L.
name: Xing, Y.
name: Xiong, Z.
name: Xu, D. L.
name: Xu, R. F.
name: Xu, R. X.
name: Xu, W. L.
name: Xue, L.
name: Yan, D. H.
name: Yan, J. Z.
name: Yan, T.
name: Yang, C. W.
name: Yang, F.
name: Yang, F. F.
name: Yang, H. W.
name: Yang, J. Y.
name: Yang, L. L.
name: Yang, M. J.
name: Yang, R. Z.
name: Yang, S. B.
name: Yao, Y. H.
name: Yao, Z. G.
name: Ye, Y. M.
name: Yin, L. Q.
name: Yin, N.
name: You, X. H.
name: You, Z. Y.
name: Yu, Y. H.
name: Yuan, Q.
name: Yue, H.
name: Zeng, H. D.
name: Zeng, T. X.
name: Zeng, W.
name: Zha, M.
name: Zhang, B. B.
name: Zhang, F.
name: Zhang, H. M.
name: Zhang, H. Y.
name: Zhang, J. L.
name: Zhang, L. X.
name: Zhang, Li
name: Zhang, P. F.
name: Zhang, P. P.
name: Zhang, R.
name: Zhang, S. B.
name: Zhang, S. R.
name: Zhang, S. S.
name: Zhang, X.
name: Zhang, X. P.
name: Zhang, Y. F.
name: Zhang, Yi
name: Zhang, Yong
name: Zhao, B.
name: Zhao, J.
name: Zhao, L.
name: Zhao, L. Z.
name: Zhao, S. P.
name: Zheng, F.
name: Zhou, B.
name: Zhou, H.
name: Zhou, J. N.
name: Zhou, M.
name: Zhou, P.
name: Zhou, R.
name: Zhou, X. X.
name: Zhu, C. G.
name: Zhu, F. R.
name: Zhu, H.
name: Zhu, K. J.
name: Zuo, X.
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at $3.67 \pm 0.05 \pm 0.15$ PeV. Below the knee, the spectral index is found to be -$2.7413 \pm 0.0004 \pm 0.0050$, while above the knee, it is -$3.128 \pm 0.005 \pm 0.027$, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -$0.1200 \pm 0.0003 \pm 0.0341$. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.
description: 8 pages, 3 figures