Reaction Rate Weighted Multilayer Nuclear Reaction Network

Abstract

Nuclear reaction rate λ is a significant factor in processes of nucleosyntheses. A multi-layer directed-weighted nuclear reaction network, in which the reaction rate is taken as the weight, and neutron, proton, 4He and the remainder nuclei as the criteria for different reaction layers, is for the first time built based on all thermonuclear reactions in the JINA REACLIB database. Our results show that with the increase in the stellar temperature T 9, the distribution of nuclear reaction rates on the R-layer network demonstrates a transition from unimodal to bimodal distributions. Nuclei on the R-layer in the region of λ = [1,2.5 × 101] have a more complicated out-going degree distribution than that in the region of λ = [1011,1013], and the number of involved nuclei at T 9 = 1 is very different from the one at T 9 = 3. The redundant nuclei in the region of λ = [1, 2.5 × 101] at T 9 = 3 prefer (γ, p) and (γ,α) reactions to the ones at T 9 = 1, which produce nuclei around the β stable line. This work offers a novel way to the big-data analysis on the nuclear reaction network at stellar temperatures.