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arXiv · 2007.00023

Search for Large-scale Anisotropy on Arrival Directions of Ultra-high-energy Cosmic Rays Observed with the Telescope Array Experiment

Telescope Array Collaboration·R. U. Abbasi·M. Abe·T. Abu-Zayyad·M. Allen·R. Azuma·E. Barcikowski·J. W. Belz·D. R. Bergman·S. A. Blake·R. Cady·B. G. Cheon·J. Chiba·M. Chikawa·A. di Matteo·T. Fujii·K. Fujisue·K. Fujita·R. Fujiwara·M. Fukushima·G. Furlich·W. Hanlon·M. Hayashi·N. Hayashida·K. Hibino·R. Higuchi·K. Honda·D. Ikeda·T. Inadomi·N. Inoue·T. Ishii·R. Ishimori·H. Ito·D. Ivanov·H. Iwakura·H. M. Jeong·S. Jeong·C. C. H. Jui·K. Kadota·F. Kakimoto·O. Kalashev·K. Kasahara·S. Kasami·H. Kawai·S. Kawakami·S. Kawana·K. Kawata·E. Kido·H. B. Kim·J. H. Kim·M. H. Kim·S. W. Kim·S. Kishigami·V. Kuzmin·M. Kuznetsov·Y. J. Kwon·K. H. Lee·B. Lubsandorzhiev·J. P. Lundquist·K. Machida·H. Matsumiya·T. Matsuyama·J. N. Matthews·R. Mayta·M. Minamino·K. Mukai·I. Myers·S. Nagataki·K. Nakai·R. Nakamura·T. Nakamura·Y. Nakamura·T. Nonaka·H. Oda·S. Ogio·M. Ohnishi·H. Ohoka·Y. Oku·T. Okuda·Y. Omura·M. Ono·R. Onogi·A. Oshima·S. Ozawa·I. H. Park·M. S. Pshirkov·J. Remington·D. C. Rodriguez·G. Rubtsov·D. Ryu·H. Sagawa·R. Sahara·Y. Saito·N. Sakaki·T. Sako·N. Sakurai·K. Sano·T. Seki·K. Sekino·P. D. Shah
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Abstract

Motivated by the detection of a significant dipole structure in the arrival directions of ultrahigh-energy cosmic rays above 8 EeV reported by the Pierre Auger Observatory (Auger), we search for a large-scale anisotropy using data collected with the surface detector array of the Telescope Array Experiment (TA). With 11 years of TA data, a dipole structure in a projection of the right ascension is fitted with an amplitude of 3.3+- 1.9% and a phase of 131 +- 33 degrees. The corresponding 99% confidence-level upper limit on the amplitude is 7.3%. At the current level of statistics, the fitted result is compatible with both an isotropic distribution and the dipole structure reported by Auger.

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Telescope Array Collaboration, R. U. Abbasi, M. Abe, T. Abu-Zayyad, M. Allen, R. Azuma, E. Barcikowski, J. W. Belz, D. R. Bergman, S. A. Blake, R. Cady, B. G. Cheon, J. Chiba, M. Chikawa, A. di Matteo, T. Fujii, K. Fujisue, K. Fujita, R. Fujiwara, M. Fukushima, G. Furlich, W. Hanlon, M. Hayashi, N. Hayashida, K. Hibino, R. Higuchi, K. Honda, D. Ikeda, T. Inadomi, N. Inoue, T. Ishii, R. Ishimori, H. Ito, D. Ivanov, H. Iwakura, H. M. Jeong, S. Jeong, C. C. H. Jui, K. Kadota, F. Kakimoto, O. Kalashev, K. Kasahara, S. Kasami, H. Kawai, S. Kawakami, S. Kawana, K. Kawata, E. Kido, H. B. Kim, J. H. Kim, M. H. Kim, S. W. Kim, S. Kishigami, V. Kuzmin, M. Kuznetsov, Y. J. Kwon, K. H. Lee, B. Lubsandorzhiev, J. P. Lundquist, K. Machida, H. Matsumiya, T. Matsuyama, J. N. Matthews, R. Mayta, M. Minamino, K. Mukai, I. Myers, S. Nagataki, K. Nakai, R. Nakamura, T. Nakamura, Y. Nakamura, T. Nonaka, H. Oda, S. Ogio, M. Ohnishi, H. Ohoka, Y. Oku, T. Okuda, Y. Omura, M. Ono, R. Onogi, A. Oshima, S. Ozawa, I. H. Park, M. S. Pshirkov, J. Remington, D. C. Rodriguez, G. Rubtsov, D. Ryu, H. Sagawa, R. Sahara, Y. Saito, N. Sakaki, T. Sako, N. Sakurai, K. Sano, T. Seki, K. Sekino, P. D. Shah. 2020-06-30. Search for Large-scale Anisotropy on Arrival Directions of Ultra-high-energy Cosmic Rays Observed with the Telescope Array Experiment. https://doi.org/10.3847/2041-8213/aba0bc

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