arXiv · 1711.10981
Direct detection of a break in the teraelectronvolt cosmic-ray spectrum of electrons and positrons
Abstract
High energy cosmic ray electrons plus positrons (CREs), which lose energy quickly during their propagation, provide an ideal probe of Galactic high-energy processes and may enable the observation of phenomena such as dark-matter particle annihilation or decay. The CRE spectrum has been directly measured up to $\sim 2$ TeV in previous balloon- or space-borne experiments, and indirectly up to $\sim 5$ TeV by ground-based Cherenkov $γ$-ray telescope arrays. Evidence for a spectral break in the TeV energy range has been provided by indirect measurements of H.E.S.S., although the results were qualified by sizeable systematic uncertainties. Here we report a direct measurement of CREs in the energy range $25~{\rm GeV}-4.6~{\rm TeV}$ by the DArk Matter Particle Explorer (DAMPE) with unprecedentedly high energy resolution and low background. The majority of the spectrum can be properly fitted by a smoothly broken power-law model rather than a single power-law model. The direct detection of a spectral break at $E \sim0.9$ TeV confirms the evidence found by H.E.S.S., clarifies the behavior of the CRE spectrum at energies above 1 TeV and sheds light on the physical origin of the sub-TeV CREs.
Explore related subjects
Keep this discovery
G. Ambrosi, Q. An, R. Asfandiyarov, P. Azzarello, P. Bernardini, B. Bertucci, M. S. Cai, J. Chang, D. Y. Chen, H. F. Chen, J. L. Chen, W. Chen, M. Y. Cui, T. S. Cui, A. D'Amone, A. De Benedittis, I. De Mitri, M. Di Santo, J. N. Dong, T. K. Dong, Y. F. Dong, Z. X. Dong, G. Donvito, D. Droz, K. K. Duan, J. L. Duan, M. Duranti, D. D'Urso, R. R. Fan, Y. Z. Fan, F. Fang, C. Q. Feng, L. Feng, P. Fusco, V. Gallo, F. J. Gan, M. Gao, S. S. Gao, F. Gargano, S. Garrappa, K. Gong, Y. Z. Gong, D. Y. Guo, J. H. Guo, Y. M. Hu, G. S. Huang, Y. Y. Huang, M. Ionica, D. Jiang, W. Jiang, X. Jin, J. Kong, S. J. Lei, S. Li, X. Li, W. L. Li, Y. Li, Y. F. Liang, Y. M. Liang, N. H. Liao, H. Liu, J. Liu, S. B. Liu, W. Q. Liu, Y. Liu, F. Loparco, M. Ma, P. X. Ma, S. Y. Ma, T. Ma, X. Q. Ma, X. Y. Ma, G. Marsella, M. N. Mazziotta, D. Mo, X. Y. Niu, X. Y. Peng, W. X. Peng, R. Qiao, J. N. Rao, M. M. Salinas, G. Z. Shang, W. H. Shen, Z. Q. Shen, Z. T. Shen, J. X. Song, H. Su, M. Su, Z. Y. Sun, A. Surdo, X. J. Teng, X. B. Tian, A. Tykhonov, V. Vagelli, S. Vitillo, C. Wang, H. Wang, H. Y. Wang, J. Z. Wang, L. G. Wang. 2017-11-29. Direct detection of a break in the teraelectronvolt cosmic-ray spectrum of electrons and positrons. https://doi.org/10.1038/nature24475
Cite the original work for its findings. Save a collection to share your selection of sources.