Are protons still dominant at the knee of the cosmic-ray energy spectrum?

doi:10.1016/j.physletb.2005.10.048

	Are protons still dominant at the knee of the cosmic-ray energy spectrum?
	Amenomori, M ; Ayabe, S ; Chen, D ; Cui, SW ; Ding, LK ; Ding, XH ; Feng, CF ; Feng, ZY ; Gao, XY ; Geng, QX
刊名	PHYSICS LETTERS B
	2006-01-05
卷号	632 页码:58-64
关键词	cosmic rays gamma-family neural network proton knee energy region
ISSN号	0370-2693
DOI	10.1016/j.physletb.2005.10.048
英文摘要	A hybrid experiment consisting of emulsion chambers, burst detectors and the Tibet-11 air-shower array was carried out at Yangbajing (4300 m a.s.l., 606 g/cm(2)) in Tibet to obtain the energy spectra of primary protons and heliums. From three-year operation, these energy spectra are deduced between 10(15) and 10(16) eV by triggering the air showers associated with a high energy core and using a neural network method in the primary mass separation. The proton spectrum can be expressed by a single power-law function with a differential index of -3.01 +/- 0.11 and -3.05 +/- 0.12 based on the QGSJET + HD and SIBYLL + HD models, respectively, which are steeper than that extrapolated from the direct observations of -2.74 +/- 0.01 in the energy range below 10 14 eV. The absolute fluxes of protons and heliums are derived within 30% systematic errors depending on the hadronic interaction models used in Monte Carlo simulation. The result of our experiment suggests that the main component responsible for the change of the power index of the all-particle spectrum around 3 x 1015 eV, so-called "knee", is composed of nuclei heavier than helium. This is the first measurement of the differential energy spectra of primary protons and heliums by selecting them event by event at the knee energy region. (c) 2005 Elsevier B.V. All rights reserved.
WOS关键词	SHOCK ACCELERATION ; HYBRID-EXPERIMENT ; REGION ; HELIUM ; NUCLEI ; TIBET
WOS研究方向	Physics
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000234520500008
内容类型	期刊论文
源URL	[http://119.78.100.186/handle/113462/26483]
专题	中国科学院近代物理研究所
通讯作者	Huang, Q
作者单位	1.Univ Tokyo, Inst Cosm Ray Res, Kashiwa, Chiba 2778582, Japan 2.Hirosaki Univ, Dept Phys, Hirosaki, Aomori 0368561, Japan 3.Saitama Univ, Dept Phys, Urawa, Saitama 3388570, Japan 4.Yokohama Natl Univ, Fac Engn, Yokohama, Kanagawa 2408501, Japan 5.Chinese Acad Sci, Inst High Energy Phys, Key Lab Particle Astrophys, Beijing 100049, Peoples R China 6.Tibet Univ, Dept Math & Phys, Lhasa 850000, Peoples R China 7.Shandong Univ, Dept Phys, Jinan 250100, Peoples R China 8.Xian Jiaotong Univ, Inst Modern Phys, Chengdu 610031, Peoples R China 9.Yunnan Univ, Dept Phys, Kunming 650091, Peoples R China 10.Kanagawa Univ, Fac Engn, Yokohama, Kanagawa 2218686, Japan
推荐引用方式 GB/T 7714	Amenomori, M,Ayabe, S,Chen, D,et al. Are protons still dominant at the knee of the cosmic-ray energy spectrum?[J]. PHYSICS LETTERS B,2006,632:58-64.
APA	Amenomori, M.,Ayabe, S.,Chen, D.,Cui, SW.,Ding, LK.,...&Zhou, XX.(2006).Are protons still dominant at the knee of the cosmic-ray energy spectrum?.PHYSICS LETTERS B,632,58-64.
MLA	Amenomori, M,et al."Are protons still dominant at the knee of the cosmic-ray energy spectrum?".PHYSICS LETTERS B 632(2006):58-64.