1. Primary proton spectrum between 200 TeV and 1000 TeV observed with the Tibet burst detector and air shower array
- Author
-
N. J. Zhang, M. He, Takeshi Saito, Danzengluobu, H. M. Zhang, H. Sugimoto, Y. Katayose, T. Yuda, J. Y. Li, A. F. Yuan, K. Hibino, Zhaxisangzhu, C. S. Zhang, Jieru Ren, S. L. Lu, I. Ohta, M. Amenomori, C. R. Wang, M. Shibata, Katsuaki Kasahara, K. Taira, Z. R. Peng, Y. Yamamoto, N. Hotta, X. Y. Zhang, K. Izu, Labaciren, Z. Y. Feng, Y. Fu, M. Sakata, T. Utsugi, Hsiao-Chi Lu, K.Mizutani K.Mizutani, T. Ouchi, X. R. Meng, Huaguang Wang, T. Sasaki, T. Shirai, Caidong, F. Kajino, Masaki Nishizawa, H. Y. Jia, J. Mu, Y. H. Tan, Q. Huang, G. X. Luo, S. Ayabe, A. Shiomi, H. Nanjo, Zhaxiciren, N. Tateyama, M. Ohnishi, Z. Z. Shi, X. W. Xu, A. X. Huo, G. C. Yu, H. W. Guo, Jia Zhang, S. Torii, and L. K. Ding
- Subjects
Physics ,Nuclear and High Energy Physics ,Range (particle radiation) ,Proton ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,Detector ,FOS: Physical sciences ,chemistry.chemical_element ,Cosmic ray ,Astrophysics ,Power law ,Nuclear physics ,Air shower ,chemistry ,High Energy Physics::Experiment ,Helium ,Energy (signal processing) - Abstract
Since 1996, a hybrid experiment consisting of the emulsion chamber and burst detector array and the Tibet-II air-shower array has been operated at Yangbajing (4300 m above sea level, 606 g/cm^2) in Tibet. This experiment can detect air-shower cores, called as burst events, accompanied by air showers in excess of about 100 TeV. We observed about 4300 burst events accompanied by air showers during 690 days of operation and selected 820 proton-induced events with its primary energy above 200 TeV using a neural network method. Using this data set, we obtained the energy spectrum of primary protons in the energy range from 200 to 1000 TeV. The differential energy spectrum obtained in this energy region can be fitted by a power law with the index of -2.97 $\pm$ 0.06, which is steeper than that obtained by direct measurements at lower energies. We also obtained the energy spectrum of helium nuclei at particle energies around 1000 TeV., 25 pages, 22 figures, Accepted for publication in Phys. Rev. D
- Published
- 2000
- Full Text
- View/download PDF