Indications for a high-rigidity break in the cosmic-ray diffusion coefficient

Yoann Genolini (1) , Pasquale Dario Serpico (1) , Mathieu Boudaud (1) , Sami Caroff (1) , Vivian Poulin (1) , Laurent Derome (1) , Julien Lavalle (1) , David Maurin (1) , Vincent Poireau (1) , Sylvie Rosier (1) , Pierre Salati (1) , Manuela Vecchi (1)

1 LAPTH - Laboratoire d'Annecy-le-Vieux de Physique Théorique

Using cosmic-ray boron to carbon ratio (B/C) data recently released by the AMS-02 experiment, we find tantalizing indications (decisive evidence, in Bayesian terms) in favor of a diffusive origin for the broken power-law spectra found in protons ($p$) and helium nuclei (He). The result is robust with respect to currently estimated uncertainties in the cross sections, and in the presence of a small component of primary boron, expected because of spallation at the acceleration site. Reduced errors at high energy as well as further cosmic ray nuclei data (as absolute spectra of C, N, O, Li, Be) may definitively confirm this scenario.

Domaines: Astrophysique [astro-ph]

Yoann Genolini, Pasquale Dario Serpico, Mathieu Boudaud, Sami Caroff, Vivian Poulin, et al.. Indications for a high-rigidity break in the cosmic-ray diffusion coefficient. 35th International Cosmic Ray Conference, Jul 2017, Busan, South Korea. pp.268, ⟨10.22323/1.301.0268⟩. ⟨hal-01890829⟩