Co-Investigator(Kenkyū-buntansha) |
YOSHIMURA Koji 高エネルギー加速器研究機構, 素粒子原子核研究所, 準教授 (50272464)
MAKITA Yasuhiro 高エネルギー加速器研究機構, 素粒子原子核研究所, 準教授 (30199658)
野崎 光昭 大学共同利用機関法人高エネルギー加速器研究機構, 素粒子原子核研究所, 教授 (10156193)
長谷川 雅也 大学共同利用機関法人高エネルギー加速器研究機構, 素粒子原子核研究所, 助教 (60435617)
吉田 哲也 宇宙航空研究関発機構, 宇宙科学研究本部, 教授 (50222394)
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Budget Amount *help |
¥104,260,000 (Direct Cost: ¥80,200,000、Indirect Cost: ¥24,060,000)
Fiscal Year 2009: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000)
Fiscal Year 2008: ¥8,840,000 (Direct Cost: ¥6,800,000、Indirect Cost: ¥2,040,000)
Fiscal Year 2007: ¥45,370,000 (Direct Cost: ¥34,900,000、Indirect Cost: ¥10,470,000)
Fiscal Year 2006: ¥43,680,000 (Direct Cost: ¥33,600,000、Indirect Cost: ¥10,080,000)
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Research Abstract |
The research program by using the Balloon-borne Experiment with a Superconducting Spectrometer (BESS) has much progressed with a long duration flight over Antarctica at soar minimum period in 2007~2008 (BESS-Polar II), as summarized as follows : (1) The antiproton spectrum measured shows good consistency with secondary antiproton model calculation. (2) Given this background of secondary antiprotons, cosmologically primary antiprotons have been searched for using the observed antiproton spectrum. The result show no evidence of primary antiprotons that originated from the evaporation of Primordial Black Holes within the obtained statistics. (3) No anti-helium candidate was detected, and a resultant up limit of 7x10E-8 for the abundance ratio of anti-helium/helium in a rigidity range of 1-14 GV by combining all the BESS and BESS-Polar data. This the most stringent limit obtained to date.
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