Rate Analysis or a Possible Interpretation of Abundances

TL;DR

This paper introduces a novel approach to analyze elemental and isotopic abundances in nucleosynthesis by changing nucleon identification to extract new information, estimating neutron densities, and defining a new branching ratio concept.

Contribution

It proposes a new method for interpreting nuclear abundances using (Z,N) identification, and introduces the partial formation rate for better neutron density characterization.

Findings

Estimated equilibrium neutron densities for nucleosynthesis.

Defined the partial formation rate as a new branching ratio measure.

Analyzed the conditions for stable and unstable nuclei in nucleosynthesis.

Abstract

Heavy elements are formed in nucleosynthesis processes. Abundances of these elements can be classified as elemental abundance, isotopic abundance, and abundance of nuclei. In this work we propose to change nucleon identification from the usual (Z,A) to (Z,N), which allows reading out new information from the measured abundances. We are interested in the neutron density required to reproduce the measured abundance of nuclei assuming equilibrium processes. This is only possible when two stable nuclei are separated by an unstable nucleus. At these places we investigated the neutron density required for equilibrium nucleosynthesis both isotopically and isotonically at temperatures of AGB interpulse and thermal pulse phases. We obtained an estimate for equilibrium nucleosynthesis neutron density in most of the cases. Next we investigated the possibility of partial formation of nuclei. We analyzed the meaning of the branching factor. We found a mathematical definition for the unified interpretation of a branching point closed at isotonic case and open at isotopic case. We introduce a more expressive variant of branching ratio called partial formation rate. With these we are capable of determining the characteristic neutron density values.