Precise Measurement of the Cosmic Ray Helium Spectrum above 0.1 PeV
Issued Date
2026-03-27
Resource Type
eISSN
10797114
Scopus ID
2-s2.0-105035571226
Pubmed ID
41965017
Journal Title
Physical Review Letters
Volume
136
Issue
12
Rights Holder(s)
SCOPUS
Bibliographic Citation
Physical Review Letters Vol.136 No.12 (2026) , 121001
Suggested Citation
Cao Z., Aharonian F., Bai Y.X., Bao Y.W., Bastieri D., Bi X.J., Bi Y.J., Bian W., Blunier J., Bukevich A.V., Cai C.M., Cai Y.Y., Cao W.Y., Cao Z., Chang J., Chang J.F., Chen E.S., Chen G.H., Chen H.K., Chen L.F., Chen L., Chen L., 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 Z.G., Danzengluobu, Diao Y.X., Dong A.J., Dong X.Q., Duan K.K., 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., Gao W.K., Ge M.M., Ge T.T., Geng L.S., Giacinti G., Gong G.H., Gou Q.B., Gu M.H., 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 B.W., Hou C., Hou X., Hu H.B., Hu S.C., Huang C., Huang D.H., Huang J.J., Huang X.L., Huang X.T., Huang X.Y., Huang Y., Huang Y.Y. Precise Measurement of the Cosmic Ray Helium Spectrum above 0.1 PeV. Physical Review Letters Vol.136 No.12 (2026) , 121001. doi:10.1103/d838-49gt Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/116274
Title
Precise Measurement of the Cosmic Ray Helium Spectrum above 0.1 PeV
Author(s)
Cao Z.
Aharonian F.
Bai Y.X.
Bao Y.W.
Bastieri D.
Bi X.J.
Bi Y.J.
Bian W.
Blunier J.
Bukevich A.V.
Cai C.M.
Cai Y.Y.
Cao W.Y.
Cao Z.
Chang J.
Chang J.F.
Chen E.S.
Chen G.H.
Chen H.K.
Chen L.F.
Chen L.
Chen L.
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 Z.G.
Danzengluobu
Diao Y.X.
Dong A.J.
Dong X.Q.
Duan K.K.
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.
Gao W.K.
Ge M.M.
Ge T.T.
Geng L.S.
Giacinti G.
Gong G.H.
Gou Q.B.
Gu M.H.
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 B.W.
Hou C.
Hou X.
Hu H.B.
Hu S.C.
Huang C.
Huang D.H.
Huang J.J.
Huang X.L.
Huang X.T.
Huang X.Y.
Huang Y.
Huang Y.Y.
Aharonian F.
Bai Y.X.
Bao Y.W.
Bastieri D.
Bi X.J.
Bi Y.J.
Bian W.
Blunier J.
Bukevich A.V.
Cai C.M.
Cai Y.Y.
Cao W.Y.
Cao Z.
Chang J.
Chang J.F.
Chen E.S.
Chen G.H.
Chen H.K.
Chen L.F.
Chen L.
Chen L.
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 Z.G.
Danzengluobu
Diao Y.X.
Dong A.J.
Dong X.Q.
Duan K.K.
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.
Gao W.K.
Ge M.M.
Ge T.T.
Geng L.S.
Giacinti G.
Gong G.H.
Gou Q.B.
Gu M.H.
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 B.W.
Hou C.
Hou X.
Hu H.B.
Hu S.C.
Huang C.
Huang D.H.
Huang J.J.
Huang X.L.
Huang X.T.
Huang X.Y.
Huang Y.
Huang Y.Y.
Author's Affiliation
University of Chinese Academy of Sciences
Tsinghua University
Shanghai Jiao Tong University
Sun Yat-Sen University
University of Science and Technology of China
Université Paris Cité
Shandong University
Nanjing University
Chinese University of Hong Kong
Southwest Jiaotong University
Yunnan University
Guangzhou University
Institute of High Energy Physics, Chinese Academy of Sciences
National Astronomical Observatories Chinese Academy of Sciences
Hebei Normal University
Max-Planck-Institut für Kernphysik
Institute for Nuclear Research of the Russian Academy of Sciences
Guizhou Normal University
Yerevan State University
China Center of Advanced Science and Technology World Laboratory
Zhejiang Lab
Purple Mountain Observatory Chinese Academy of Sciences
Shanghai Astronomical Observatory Chinese Academy of Sciences
Yunnan Observatories
Tibet University
State Key Laboratory of Particle Detection & Electronics
TIANFU Cosmic Ray Research Center
Tsinghua University
Shanghai Jiao Tong University
Sun Yat-Sen University
University of Science and Technology of China
Université Paris Cité
Shandong University
Nanjing University
Chinese University of Hong Kong
Southwest Jiaotong University
Yunnan University
Guangzhou University
Institute of High Energy Physics, Chinese Academy of Sciences
National Astronomical Observatories Chinese Academy of Sciences
Hebei Normal University
Max-Planck-Institut für Kernphysik
Institute for Nuclear Research of the Russian Academy of Sciences
Guizhou Normal University
Yerevan State University
China Center of Advanced Science and Technology World Laboratory
Zhejiang Lab
Purple Mountain Observatory Chinese Academy of Sciences
Shanghai Astronomical Observatory Chinese Academy of Sciences
Yunnan Observatories
Tibet University
State Key Laboratory of Particle Detection & Electronics
TIANFU Cosmic Ray Research Center
Corresponding Author(s)
Other Contributor(s)
Abstract
We report a measurement of the cosmic ray helium energy spectrum in the energy interval 0.16-13 PeV, derived by subtracting the proton spectrum from the light component (proton and helium) spectrum obtained with observations made by the Large High Altitude Air Shower Observatory (LHAASO) under a consistent energy scale. The helium spectrum shows a significant hardening centered at E≃1.1 PeV, followed by a softening at ∼7 PeV, indicating the appearance of a helium "knee." Comparing the proton and helium spectra in the LHAASO energy range reveals some remarkable facts. In the lower part of this range, in contrast to the behavior at lower energies, the helium spectrum is significantly softer than the proton spectrum. This results in protons overtaking helium nuclei and becoming the largest cosmic ray component at E≃0.7 PeV. A second crossing of the two spectra is observed at E≃5 PeV, above the proton knee, when helium nuclei overtake protons to become the largest cosmic ray component again. These results have important implications for our understanding of the Galactic cosmic ray sources.