Measurement of the cosmic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>p</mml:mi><mml:mo>+</mml:mo><mml:mi>He</mml:mi></mml:mrow></mml:math> energy spectrum from 50 GeV to 0.5 PeV with the DAMPE space mission
Francesco Alemanno, Corrado Altomare, Q. An, P. Azzarello, Felicia Barbato, P. Bernardini, Xiao-Jun Bi, I. Cagnoli, Mingsheng Cai, E. Casilli, E. Catanzani, J. F. Chang, D. Y. Chen, J. L. Chen, Z. F. Chen, Paul Coppin, Maxwell Cui, T. S. Cui, Yuxin Cui, Haoting Dai, A. De Benedittis, I. De Mitri, F. de Palma, M. Deliyergiyev, A. Di Giovanni, Margherita Di Santo, Qiurong Ding, Ting Dong, Z. X. Dong, Giacinto Donvito, David Droz, Jinglai Duan, K. K. Duan, Ruirui Fan, Y. Z. Fan, F. Fang, Ke Fang, C. Q. Feng, Lei Feng, M. Fernández Alonso, Jennifer Maria Frieden, P. Fusco, M. Gao, F. Gargano, Ke Gong, Yuanlin Gong, D. Y. Guo, Jian Guo, Songling Han, Yi-Ming Hu, G. S. Huang, X. Y. Huang, Y. Huang, M. Ionica, Libo Jiang, Yi Jiang, Wei Jiang, Jie Kong, Andrii Kotenko, Dimitrios Kyratzis, S. J. Lei, W. H. Li, W. L. Li, X Li, Xuanle Li, Yan Liang, C. M. Liu, H. Liu, Jiangying Liu, S. B. Liu, Ye Liu, F. Loparco, C. N. Luo, Ming Ma, Peng-Xiong Ma, T. Ma, X. Y., G. Marsella, M. N. Mazziotta, Di Mo, M. Muoz Salinas, X. Y. Niu, X. Pan, A. Parenti, W. X. Peng, Xinyong Peng, C. Perrina, Enzo Putti-Garcia, Rui Qiao, J. N. Rao, Arshia Ruina, Z. Shangguan, W. H. Shen, Zhao-Qiang Shen, Z. T. Shen, Leandro Silveri, J. X. Song, M. Stolpovskiy, Hongbo Su, Meng Su
Abstract
Recent observations of the light component of the cosmic-ray spectrum have revealed unexpected features that motivate further and more precise measurements up to the highest energies. The Dark Matter Particle Explorer is a satellite-based cosmic-ray experiment that has been operational since December 2015, continuously collecting data on high-energy cosmic particles with very good statistics, energy resolution, and particle identification capabilities. In this work, the latest measurements of the energy spectrum of $\mathrm{proton}+\mathrm{helium}$ in the energy range from 46 GeV to 464 TeV are presented. Among the most distinctive features of the spectrum, a spectral hardening at 600 GeV has been observed, along with a softening at 29 TeV measured with a $6.6\ensuremath{\sigma}$ significance. Moreover, the detector features and the analysis approach allowed for the extension of the spectral measurement up to the sub-PeV region. Even if with small statistical significance due to the low number of events, data suggest a new spectral hardening at about 150 TeV.