Year: 2026
Type: preprint
Abstract: Ultra-relativistic magnetic monopoles traversing the atmosphere are expected to initiate extensive air showers characterized by a muon deficit and a compact lateral profile. Using 1438.81 live days of data from the LHAASO-KM2A array, we present a search for these cosmic particles within the Lorentz factor range of $10^5$ to $10^7$. A machine-learning classifier utilizing lateral shower shape observables from the electromagnetic detectors is deployed to separate the signal from the hadronic background. No statistical excess above the background expectation is observed, and upper limits at the 90\% confidence level are established on the isotropic monopole flux. The resulting upper limit is $2.6 \times 10^{-16}\,\mathrm{cm}^{-2}\,\mathrm{s}^{-1}\,\mathrm{sr}^{-1}$ at $γ= 10^5$ and reaches $8.8 \times 10^{-19}\,\mathrm{cm}^{-2}\,\mathrm{s}^{-1}\,\mathrm{sr}^{-1}$ at $γ= 10^7$, which improves upon the astrophysical Parker bound by over three orders of magnitude. This work establishes constraints on the monopole flux within a previously unconstrained velocity window.
Source: arXiv (Cornell University)
Authors: Cao, Zhen, Aharonian, F., Bai, Y. X., Bao, Y. W., Bastieri, D., Bi, X. J., Bi, Y. J., Bian, W., Blunier, J., Butkevich, A. V., Cai, C. M., Cao, W. Y., Cao, Zhe, Chang, J., Chang, J. F., Chen, E. S., Chen, G. H., Chen, H. K., Chen, L. F., Chen, Liang, Chen, Long, Chen, M. J., Chen, M. L., Chen, Q. H., Chen, S., Chen, S. H., Chen, S. Z., Chen, T. L., Chen, X. B., Chen, X. J., Chen, X. P., Chen, Y., Cheng, N., Cheng, Q. Y., Cheng, Y. D., Cui, M. Y., Cui, S. W., Cui, X. H., Cui, Y. D., Dai, B. Z., Dai, H. L., Dai, L. X., Dai, Z. G., Danzengluobu, Diao, Y. X., Dong, A. J., Duan, K. K., Duan, X. D., Fan, J. H., Fan, Y. Z., Fang, J., Fang, J. H., Fang, K., Feng, C. F., Feng, H., Feng, L., Feng, S. H., Feng, X. T., Feng, Y., Feng, Y. L., Gabici, S., Gao, B., Gao, Q., Gao, W., Ge, C., Ge, M. M., Ge, T. T., Geng, L. S., Giacinti, G., Gong, G. H., Gou, Q. B., Gu, M. H., Gu, W. M., Guo, F. L., Guo, J., Guo, K. J., Guo, X. L., Guo, Y. Q., Guo, Y. Y., Han, R. P., Hannuksela, O. A., Hasan, M., He, H. H., He, H. N., He, J. Y., He, X. Y., He, Y., Hernández-Cadena, S., Hou, C., Hou, X., Hu, H. B., Hu, S. C., Huang, C., Huang, D. H., Huang, F., Huang, J. J., Huang, X. L., Huang, X. T., Huang, X. Y., Huang, Y., Huang, Z. J., Huang, Z. Q., Inventar, A., Ji, X. L., Jia, H. Y., Jia, K., Jiang, H. B., Jiang, K., Jiang, X. W., Jiang, Z. J., Jin, M., Kaci, S., Kang, M. M., Karpikov, I., Khangulyan, D., Kuleshov, D., Kurinov, K., Lei, W. H., Li, Cheng, Li, Cong, Li, D., Li, F., Li, H. B., Li, H. C., Li, Jian, Li, Jie, Li, K., Li, L., Li, R. L., Li, T. Y., Li, W. L., Li, X. R., Li, X. Y., Li, Y., Li, Zhe, Li, Zhuo, Liang, E. W., Liang, Y. F., Lin, S. J., Liu, B., Liu, C., Liu, D., Liu, D. B., Liu, H., Liu, J., Liu, J. F., Liu, J. L., Liu, J. R., Liu, M. Y., Liu, Q., Liu, R. Y., Liu, S. M., Liu, T., Liu, W., Liu, Y., Liu, Y., Liu, Y. N., Lou, Y. Q., Luo, Q., Luo, Y., Lv, H. K., Ma, B. Q., Ma, L. L., Ma, X. H., Maliy, I. O., Mao, J. R., Min, Z., Mitthumsiri, W., Mizuno, Y., Mou, G. B., Neronov, A., Ng, C. -Y., Ng, K. C. Y., Ni, M. Y., Nie, L., Ou, L. J., Ou, Z. W., Pattarakijwanich, P., Pei, Z. Y., Peng, D. Y., Qi, J. C., Qi, M. Y., Qin, J. J., Qu, H., Raza, A., Ren, C. Y., Ruan, M. Q., Ruffolo, D., Sáiz, A., Savchenko, D., Semikoz, D., Shao, L., Shchegolev, O., Shen, Y. Z., Sheng, X. D., Shu, F. W., Song, H. C., Stenkin, Yu. V., Su, Y., Sun, C. Y., Sun, D. X., Sun, H., Sun, J. X., Sun, M., Sun, Q. N., Sun, X. N., Sun, Z. B., Tabasam, N. H., Takata, J., Tam, P. H. T., Tan, H. B., Tang, Q. W., Tang, R., Tang, Z. B., Tian, W. W., Tong, C. N., Wan, L. H., Wang, C., Wang, D. H., Wang, G. W., Wang, H. G., Wang, J. C., Wang, J. F., Wang, J. S., Wang, K., Wang, Kai, Wang, Kai, Wang, L. P., Wang, L. Y., Wang, W., Wang, X. G., Wang, X. J., Wang, X. Y., Wang, Y., Wang, Y. D., Wang, Z. H., Wang, Z. X., Wang, Zheng, Wei, D. M., Wei, J. J., Wei, Y. J., Wen, T., Weng, S. S., Wu, C. Y., Wu, H. R., Wu, Q. W., Wu, S., Wu, X. F., Wu, Y. S., Xi, S. Q., Xia, J., Xiang, G. M., Xiao, D. X., Xiao, G., Xiao, Y. F., Xie, B. H., Xie, F., Xin, Y. L., Xing, H. D., Xing, Y., Xiong, D. R., Xu, B. N., Xu, C. Y., Xu, D. L., Xu, R. X., Xu, S. S., Xue, L., Yan, D. H., Yan, T., Yang, C., Yang, C. Y., Yang, F. F., Yang, L. L., Yang, M. J., Yang, R. Z., Yang, W. X., Yang, Z. H., Yao, Z. G., Ye, X. A., Yin, L. Q., Yin, N., You, X. H., You, Z. Y., Yu, Y. H., Yuan, Q., Yue, H., Zeng, H. D., Zeng, T. X., Zeng, W., Zeng, X. T., Zha, M., Zhang, B., Zhang, B. B., Zhang, B. T., Zhang, C., Zhang, H., Zhang, H. M., Zhang, H. Y., Zhang, J. L., Zhang, J. Y., Zhang, L. Y., Zhang, Li, Zhang, P. F., Zhang, R., Zhang, R. Y., Zhang, S. R., Zhang, S. S., Zhang, S. Y., Zhang, W., Zhang, X., Zhang, X. L., Zhang, X. P., Zhang, Yi, Zhang, Yong, Zhang, Z. P., Zhang, Z. H., Zhao, J., Zhao, L., Zhao, L. Z., Zhao, S. P., Zhao, X. H., Zheng, F., Zheng, T. C., Zhou, B., Zhou, H., Zhou, J. N., Zhou, L., Zhou, M., Zhou, P., Zhou, R., Zhou, X. X., Zhou, X. X., Zhu, B. Y., Zhu, C. G., Zhu, F. R., Zhu, H., Zhu, K. J., Zhu, Y. F., Zhu, Z. F., Zou, Y. C., Zuo, X.
Institutions: Chinese Academy of Sciences, Institute of High Energy Physics, Shanghai Jiao Tong University, Guangzhou University, Southwest Jiaotong University, Centre National de la Recherche Scientifique, Université Paris Cité, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Observatoire de Paris, Laboratoire AstroParticule et Cosmologie, Institut National de Physique Nucléaire et de Physique des Particules, Institut de Recherche sur les Lois Fondamentales de l'Univers, Institute for Nuclear Research, Chinese University of Hong Kong, Hebei Normal University, Shanghai Astronomical Observatory, Yunnan University, Purple Mountain Observatory, Nanjing University, National Astronomical Observatories, Sun Yat-sen University, University of Science and Technology of China, Guizhou Normal University, Henan Normal University, Zhejiang Lab, Shandong University, Xiamen University, Yunnan Observatories, University of Hong Kong, Tsinghua University, University of Chinese Academy of Sciences
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223323805