The role of electron capture decay in the precision era of Galactic cosmic-ray data

TL;DR

This paper assesses how electron capture decay influences high-precision cosmic-ray flux measurements, emphasizing its importance for accurate modeling in the era of detailed cosmic-ray data from AMS-02 and other experiments.

Contribution

It provides a revised steady-state flux model including electron capture decay, highlighting its significant impact on certain elemental and isotopic cosmic-ray fluxes.

Findings

EC decay impacts flux measurements at or above current experimental precision.

Proper inclusion of EC decay is essential for accurate cosmic-ray modeling.

EC decay effects are notable for elements like Ga and As.

Abstract

Electron capture (EC) decay relies on attachment and stripping cross-sections, that in turn, depend on the atomic number of the nucleus. We revisit the impact of EC decay in the context of the high-precision cosmic-ray fluxes measured by the AMS-02 experiment. We derive the solution of the steady-state fluxes in a 1D thin disk model including EC decay. We compare our results with relevant elemental and isotopic fluxes and evaluate the impact of this process, given the precision of recent AMS-02, ACE-CRIS, SuperTIGER, and Voyager data. We find this impact to be at the level or larger than the precision of recently collected data for several species, e.g. $_{31}$Ga and $_{33}$As, indicating that EC decay must be properly taken into account in the calculation.