@inproceedings{d9d53abbfd824618b135745855f38fc4,
title = "Search for cosmic-ray antideuterons with BESS-Polar II",
abstract = "High precision cosmic-ray antiproton fluxes recently reported by BESS-Polar and PAMELA are consistent with secondary production from interactions of primary cosmic rays with the interstellar medium. This severely constrains the possibility of antiprotons of primary origin such as annihilation of supersymmetric dark matter or evaporation of primordial black holes. In the case of antideuterons, however, secondary production in collisions is strongly suppressed, especially at low energies, because of the very low production cross-section and strict kinematic requirements compared to antiproton production. The lack of secondary background would imply that there is still plenty of room to search for primary antideuterons from novel production processes. In spite of such attractive features, antideuterons detection is enormously challenging since the expected flux is extremely small and superior particle identification is necessary to separate antideuteron candidates from the antiproton background. The most sensitive reported search used BESS flight data obtained during the previous solar minimum period in 1997. By comparison, the BESS-Polar II flight in 2007/2008 accumulated cosmic-ray data in near solar minimum conditions with more than ten times the statistics of BESS97. We will report the result of a new search for antideuterons with unprecedented sensitivity using BESS-Polar II.",
keywords = "BESS-Polar, Cosmic-ray antideuteron, Solar minimum, Superconducting spectrometer",
author = "K. Yoshimura and K. Abe and H. Fuke and S. Haino and T. Hams and M. Hasegawa and A. Horikoshi and Kim, {K. C.} and A. Kusumoto and Lee, {M. H.} and Y. Makida and S. Matsuda and Y. Matsukawa and Mitchell, {J. W.} and J. Nishimura and M. Nozaki and R. Orito and Ormes, {J. F.} and K. Sakai and M. Sasaki and Seo, {E. S.} and R. Shinoda and Streitmatter, {R. E.} and J. Suzuki and K. Tanaka and N. Thakur and T. Yamagami and A. Yamamoto and T. Yoshida",
note = "Funding Information: The authors thank NASA Headquarters for the continuous encouragement in this U.S.-Japan cooperative project. Sincere thanks are expressed to the NASA Balloon Programs Office at GSFC/WFF and CSBF for their experienced support. They also thank ISAS/JAXA and KEK for their continuous support and encouragement. Special thanks go to the National Science Foundation (NSF), U.S.A., and Raytheon Polar Service Company for their professional support in U.S.A. and in Antarctica. The BESS-Polar experiment is being carried out as a Japan-U.S. collaboration, and is supported by a KAKENHI( 13001004,18104006, and 22540322) in Japan, and by NASA in U.S.A. Funding Information: The authors thank NASA Headquarters for the continuous encouragement in this U.S.-Japan cooperative project. Sincere thanks are expressed to the NASA Balloon Programs Office at GSFC/WFF and CSBF for their experienced support. They also thank ISAS/JAXA and KEK for their continuous support and encouragement. Special thanks go to the National Science Foundation (NSF), U.S.A., and Raytheon Polar Service Company for their professional support in U.S.A. and in Antarctica. The BESS-Polar experiment is being carried out as a Japan-U.S. collaboration, and is supported by a KAKENHI(13001004,18104006, and 22540322) in Japan, and by NASA in U.S.A. Publisher Copyright: {\textcopyright} 2013 Sociedade Brasileira de Fisica. All Rights Reserved.; 33rd International Cosmic Rays Conference, ICRC 2013 ; Conference date: 02-07-2013 Through 09-07-2013",
year = "2013",
language = "English",
series = "Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013",
publisher = "Sociedade Brasileira de Fisica",
booktitle = "Proceedings of the 33rd International Cosmic Rays Conference, ICRC 2013",
address = "Brazil",
}