Nuclear Reaction Network Unveils Novel Reaction Patterns and Nuclei Stability

Abstract

Despite the advances in discovering new nuclei, modeling microscopic nuclear structure, nuclear reactors, and stellar nucleosynthesis, we lack a systemic tool, in the form of a network framework, to understand the structure and dynamics of 70 thousands reactions discovered until now. We assemble here a nuclear reaction network in which a node represents a nuclide, and a link represents a direct reaction between nuclides. Interestingly, the degree distribution of nuclear network exhibits a bimodal distribution that significantly deviates from the power-law distribution of scale-free networks and Poisson distribution of random networks. The distribution is universal for reactions with a rate below the threshold, λ-Tγ, where T is the temperature and γ≈1.05. We discovered three rules that govern the structure pattern of nuclear reaction network: (i) reaction-type is determined by linking choices, (ii) spatial distances between the reacting nuclides are short, and (iii) each node in- and out- degrees are close to each other. By incorporating these three rules, our model unveils the underlying nuclear reaction patterns hidden in a large and dense nuclear reaction network. It enables us to predict missing links that represent possible new nuclear reactions not yet discovered.