Observation of the anisotropy of 10 TeV primary cosmic ray nuclei flux with the Super-Kamiokande-I detector
Year: 2007
Type: article
Abstract: The relative sidereal variation in the arrival direction of primary cosmic ray nuclei of median energy 10 TeV was measured using downward, through-going muons detected with the Super-Kamiokande-I detector. The projection of the anisotropy map onto the right ascension axis has a first harmonic amplitude of $(6.64\ifmmode\pm\else\textpm\fi{}0.98\text{ }\text{ }\mathrm{stat}\ifmmode\pm\else\textpm\fi{}0.55\text{ }\text{ }\mathrm{syst})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and a phase at maximum at ($33.2\ifmmode^\circ\else\textdegree\fi{}\ifmmode\pm\else\textpm\fi{}8.2\ifmmode^\circ\else\textdegree\fi{}\text{ }\text{ }\mathrm{stat}\ifmmode\pm\else\textpm\fi{}5.1\ifmmode^\circ\else\textdegree\fi{}\text{ }\text{ }\mathrm{syst}$) right ascension. A sky map in equatorial coordinates indicates an excess region in the constellation of Taurus and a deficit region toward Virgo. The excess region is centered at $({\ensuremath{\alpha}}_{T},{\ensuremath{\delta}}_{T})=(75\ifmmode^\circ\else\textdegree\fi{}\ifmmode\pm\else\textpm\fi{}7\ifmmode^\circ\else\textdegree\fi{},\ensuremath{-}5\ifmmode^\circ\else\textdegree\fi{}\ifmmode\pm\else\textpm\fi{}9\ifmmode^\circ\else\textdegree\fi{})$ with a half-opening angle ${\ensuremath{\chi}}_{T}=(39\ifmmode\pm\else\textpm\fi{}7)\ifmmode^\circ\else\textdegree\fi{}$; the excess flux is $(0.104\ifmmode\pm\else\textpm\fi{}0.020)%$ above the isotropic expectation. The corresponding parameters for the deficit region are $({\ensuremath{\alpha}}_{V},{\ensuremath{\delta}}_{V})=(205\ifmmode^\circ\else\textdegree\fi{}\ifmmode\pm\else\textpm\fi{}7\ifmmode^\circ\else\textdegree\fi{},5\ifmmode^\circ\else\textdegree\fi{}\ifmmode\pm\else\textpm\fi{}10\ifmmode^\circ\else\textdegree\fi{})$, ${\ensuremath{\chi}}_{V}=(54\ifmmode\pm\else\textpm\fi{}7)\ifmmode^\circ\else\textdegree\fi{}$, and $(\ensuremath{-}0.094\ifmmode\pm\else\textpm\fi{}0.014)%$. The data do not allow us to rule out a pure dipole form for the anisotropy (allowed at 13% confidence level); they are better described by the excess and deficit cones described above. We explored the implications under the assumption that the true anisotropy is not distorted too much by the analysis filter so that it is well-described by the observed excess and deficit cones.
Authors: G. Guillian, J. Hosaka, K. Ishihara, J. Kameda, Y. Koshio, A. Minamino, C. Mitsuda, M. Miura, S. Moriyama, M. Nakahata, T. Namba, Y. Obayashi, H. Ogawa, M. Shiozawa, Y. Suzuki, A. Takeda, Y. Takeuchi, S. Yamada, I. Higuchi, M. Ishitsuka, T. Kajita, K. Kaneyuki, G. Mitsuka, S. Nakayama, H. Nishino, A. Okada, K. Okumura, C. Saji, Y. Takenaga, S. Desai, E. Kearns, J. L. Stone, L. R. Sulak, W. Wang, M. Goldhaber, D. Casper, W. Gajewski, J. Griskevich, W. R. Kropp, D. W. Liu, S. Mine, M. B. Smy, H. W. Sobel, M. R. Vagins, K. S. Ganezer, J. Hill, W. E. Keig, K. Scholberg, C. W. Walter, R. W. Ellsworth, S. Tasaka, A. Kibayashi, J. G. Learned, S. Matsuno, M. D. Messier, Y. Hayato, A. K. Ichikawa, T. Ishida, T. Ishii, T. Iwashita, T. Kobayashi, T. Nakadaira, K. Nakamura, K. Nitta, Y. Oyama, Y. Totsuka, A. T. Suzuki, M. Hasegawa, I. Kato, H. Maesaka, T. Nakaya, K. Nishikawa, H. Sato, S. Yamamoto, M. Yokoyama, T. J. Haines, S. Dazeley, S. Hatakeyama, R. Svoboda, E. Blaufuss, J. A. Goodman, G. W. Sullivan, D. Turcan, A. Habig, Y. Fukuda, Y. Itow, M. Sakuda, M. Yoshida, S. B. Kim, J. Yoo, H. Okazawa, T. Ishizuka, C. K. Jung, T. Kato, K. Kobayashi, M. Malek, C. Mauger, C. McGrew, E. Sharkey, C. Yanagisawa, Y. Gando, T. Hasegawa, K. Inoue, J. Shirai, A. Suzuki, K. Nishijima, H. Ishino, Y. Watanabe, M. Koshiba, D. Kielczewska, H. G. Berns, R. Gran, K. K. Shiraishi, A. L. Stachyra, K. Washburn, R. J. Wilkes, K. Munakata
Institutions: University of Hawaiʻi at Mānoa, University of Hawaii System, Institute for Cosmic Ray Research, Kamioka Observatory, The University of Tokyo, Boston University, Brookhaven National Laboratory, University of California, Irvine, California State University, Dominguez Hills, Duke University, George Mason University, Gifu University, Indiana University Bloomington, Indiana University, High Energy Accelerator Research Organization, Tohoku University, Research Center for Neutrino Science, Tohoku University, Kobe University, Kyoto University, Los Alamos National Laboratory, Louisiana State University, University of Maryland, College Park, University of Minnesota, Duluth, Miyagi University of Education, Nagoya University, Okayama University, The University of Osaka, Seoul National University, Shizuoka University, Stony Brook University, Tokai University, Tokyo Institute of Technology, University of Warsaw, University of Washington, Shinshu University
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2106964036