Study of cosmic ray propagation using GALPROP

Significant spectral hardening at around 200 GV magnetic rigidity has been reported by AMS-02, ATIC- 2, CALET, CREAM, DAMPE, and PAMELA. This has been observed in high-accuracy measurements of various nuclei energy spectra of both primaries and secondaries. To explain the spectral hardening while maintaining proper B/C and p/He ratios, we study 3 approaches in a reacceleration model: adding a diffusion coefficient break, introducing extra source injection breaks, and a combination of both. We use the numerical code GALPROP to compute the propagation of cosmic rays with such parameter sets on the rigidity dependence of source and propagation parameters. Implications on the positron spectra are discussed.