Grant-in-Aid for Overseas Scientific Survey.
|Research Institution||Science and Engineering Research Laboratory, Waseda University.|
FUJIMOTO Yoichi Waseda University., 理工学研究所, 教授 (20063290)
SLAVATINSKY レベデフ物理学研究所, 教授
SHIBUYA E.H. カンピーナス大学, 物理学研究所, 助教授
LATTES C.M.G ブラジル物理学研究センター, 教授
大沢 昭則 東京大学, 宇宙線研究所, 助手 (50013420)
横井 敬 青山学院大学, 理工学部, 教授 (50082780)
船山 吉視 早稲田大学, 理工学研究所, 助手 (40202296)
長谷川 俊一 早稲田大学, 理工学研究所, 教授 (10063398)
S.A. SLAVATI レベデフ物理学研究所, 教授
E.H. SHIBUYA カンピーナス大学物理学研究所, 助教授
C.M.G. LATTE ブラジル物理学研究センター, 教授
玉田 雅宣 近畿大学, 理工学部, 講師 (70163673)
SLAVATINSKY Sergei A. P.N. Lebedev Physical Institute.
SHIBUYA Edison H. Instituto de Fisica, Universidade Estadual de Campinas.
LATTES Cesar M.G. Contro Brasileiro de Pesquisas Fisicas.
TAMADA Masanobu Faculty of Science and Engineering, Kinki University.
OHSAWA Akinori Institute for Cosmic Ray Research, University of Tokyo.
HASEGAWA Shun-ichi Science and Engineering research Laboratory, Waseda University.
YOKOI Kei Faculty of Science and Engineering, Aoyama Gakuin University.
|Project Fiscal Year
1990 – 1992
Completed(Fiscal Year 1992)
|Budget Amount *help
¥13,000,000 (Direct Cost : ¥13,000,000)
Fiscal Year 1992 : ¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 1991 : ¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 1990 : ¥7,000,000 (Direct Cost : ¥7,000,000)
|Keywords||Cosmic-rays / Emulsion chamber / Multiple particle production / Cosmic-ray exotic events / Centauro / Feynman scaling law / 宇宙線 / エマルション・チャンバー / 粒子多重発生 / 宇宙線特異事例 / センタウロ / ファインマン・スケーリング則 / エマルション・チェンバ- / 粒子多重発生現象 / 宇宙線特異現象 / ファインマン・スケ-リング則 / チャカルタヤ / スケ-リング則|
(1) The emulsion chambers of the following types were constructed at Chacaltaya Observatory (5,200m, Bolivia) on 7-22 Mar.1991.
Disassemblage of the chambers was made on 6-16 Oct. 1992, and the photographic processing of X-ray films was made on 26 Oct. - 13 Nov. in Campinas University in Brasil. X-ray films after the development were distributed to the participating institutions, and the measurement of the showers in the observed families is under way.
Air shower array, located so as to surround the emulsion chamber, was operated simultaneously and therefore the data of air showers, accompanying the families, are available for high energy events.
(2) The international workshop on 'Super-High Energy Hadron Interactions' was held in Tokyo on 8-12 Oct. 1991, under the auspices of this program. The goals of the workshop were to summarize the present status of the studies on high energy nuclear interactions, to discuss the meaning of cosmic-ray exotic events (see below) and to discuss the dire
ction of future cosmic-ray experiments to study nuclear interactions.
More than 50 participants (including 12 from abroad among whom 8 were supported by this program) in the fields of cosmic-ray, high energy and elementary particle physics attended the workshop.
(3) The following are the main points on high energy nuclear interactions, which were made clear through the activity of this program.
.strong break-down of Feynman scaling law in the forward region in pion multiple production,
.steady accumulation of candidates of cosmic-ray exotic events,
.rapid energy dissipation in nuclear interactions, observed by the experiment to operate the emulsion chamber and air shower arry simultaneously.
The cosmic-ray exotic events of Centauro, etc., which were observed by emulsion chamber experiments at Mt. Chacaltaya, are assumed tentatively to be the multiple production of non-pionic particles, and can be classified into several types experimentally. The facts listed above indicate that there is a change of the characteristics in nuclear interactions at high energy. To explain all of these facts in a unified way, we propose as a working hypothesis that in the energy region exceeding 10^<16> eV there exists a new channel which transmutes ordinary hadrons (h) into exotic hadrons (h') via quark-gluon plasma phase. And exotic hadrons have several states corresponding to the several types of cosmic-ray exotic events. Less