Precision Measurement of the Boron to Carbon Flux Ratio in Cosmic Rays from 1.9 GV to 2.6 TV with the Alpha Magnetic Spectrometer on the International Space Station

Authors: M. Aguilar, L. Ali Cavasonza, G. Ambrosi, L. Arruda, N. Attig, S. Aupetit, P. Azzarello, A. Bachlechner, F. Barão, Aurélien Barrau, L. Barrin, A. Bartoloni, L. Basara, Seth Pree, Markus Battarbee, R. Battiston, U. Becker, M. Behlmann, B. Beischer, J. Berdugo, B. Bertucci, K. F. Bindel, V. Bindi, G. Boella, W. De Boer, K. Bollweg, V. Bonnivard, B. Borgia, M. J. Boschini, M. Bourquin, E. F. Bueno, Johanna Bürger, F. Cadoux, X.D. Cai, M. Capell, Sami Caroff, J. Casaus, G. Castellini, F. Cervelli, M. J. Chae, Yin-Jung Chang, A. I. Chen, G. M. Chen, H. S. Chen, Lin Cheng, H. Y. Chou, E. Choumilov, V. Choutko, C. H. Chung, C. Clark, R. Clavero, G. Coignet, C. Consolandi, A. Contin, C. Corti, W. Creus, M. Crispoltoni, Z. Cui, Ye Dai, C. Delgado, S. Della Torre, O. Demakov, B. Demirköz, L. Derome, S. Di Falco, F. Dimiccoli, C. Díaz, P. von Doetinchem, Fang Dong, F. Donnini, M. Duranti, D. D’Urso, A. I. Egorov, A. Eline, T. Eronen, J. H. Feng, E. Fiandrini, E. Finch, P.H. Fisher, V. Formato, Yu. Galaktionov, G. Gallucci, B. Garćıa, R. J. Garcı́a López, Corrado Gargiulo, H. Gast, Iris Gebauer, M. Gervasi, A. Ghelfi, F. Giovacchini, P. Goglov, D. M. Gómez-Coral, J. Gong, C. Goy, Varlen Grabski, D. Grandi, M. Graziani, K. H. Guo, S. Haino, K. C. Han, Z. H. He, M. Heil, J. Hoffman, Timothy H. Hsieh, H. Huang, Z. C. Huang, C. Huh, M. Incagli, M. Ionica, W. Jang, H. Jinchi, S. C. Kang, K. Kanishev, G. N. Kim, K. S. Kim, Th. Kirn, C. Konak, O. Kounina, A. Kounine, V. Koutsenko, M. S. Krafczyk, G. La Vacca, E. Laudi, G. Laurenti, I. Lazzizzera, A. Lebedev, H. T. Lee, S. C. Lee, C. Leluc, H. S. Li, J. Q. Li, J. Q. Li, Q. Li, T. X. Li, W. Lin, Y. Li, Z. H. Li, Z. Y. Li, Soobin Lim, Chao‐Hung Lin, P. Lipari, Thomas Lippert, D. Liu, Hu Liu, V. D. Lordello, S. Q. Lu, Yao Lu, K. Luebelsmeyer, Feng Luo, J. Luo, S. S. Lv, F. Machate, R. Majka, C. Mañá, J. Marín, T. Martin, G. Martínez, N. Masi, D. Maurin, A. Menchaca-Rocha, Q. Meng, V. M. Mikuni, Dong-Chuan Mo, L. Morescalchi, P. Mott, T. Nelson, J. Q. Ni, N. Nikonov, F. Nozzoli, A. Oliva, M. Orcinha, F. Palmonari, C. Palomares, M. Paniccia, M. Pauluzzi, S. Pensotti, R. M. Faisca Rodrigues Pereira, N. Picot-Clémente, F. Pilo, C. Pizzolotto, V. Plyaskin, M. Pohl, V. Poireau, A. Putze, L. Quadrani, X. M. Qi, X. Qin, Z. Y. Qu, T. Räihä, P.G. Rancoita, D. Rapin, J. S. Ricol, S. Rosier-Lees, A. Rozhkov, D. Rozza, R. Z. Sagdeev, J. Sandweiss, P. Saouter, S. Schael, Sebastian M. Schmidt, A. Schulz von Dratzig, G. Schwering, E. S. Seo, B. S. Shan, J. Y. Shi, T. Siedenburg, D. Son, Jiwei Song, W. H. Sun, M. Tacconi, X. Tang, Zhi-Cheng Tang, L. Y. Tao, D. Tescaro, Samuel C.C. Ting, S.M. Ting, Nicola Tomassetti, J. Torsti, C. Türkoğlu, T. Urban, V. Vagelli, E. Valente, C. Vannini, E. Valtonen, M. Vázquez Acosta, M. Vecchi, M. Velasco, J. P. Vialle, V. Vitale, S. Vitillo, L. Q. Wang, H. Wang, Qiuliang Wang, X. Wang, X. Q. Wang, Z. X. Wang, Chuncheng Wei, Z. Weng, Kathryn Whitman, J. Wienkenhöver, H. Wu, X. Wu, X. M. Xia, R. Q. Xiong, W. Xu, Qi Yan, J. Yang, Min Yang, Y. Yang, Hemian Yi, Yaxin Yu, Z. Q. Yu, S. Zeissler, C. Zhang, J. Zhang, J. H. Zhang, S. D. Zhang, S. W. Zhang, Z. Zhang, Z. M. Zheng, Z. Q. Zhu, H.L. Zhuang, V. Zhukov, A. Zichichi, N. Zimmermann, P. Zuccon - Physical Review Letters 2016 cited by 331

Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law R^{Δ} with index Δ=-0.333±0.014(fit)±0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts Δ=-1/3 asymptotically.