Unraveling the Role of Neutrino Processes on the Astrophysical Production of 94Mo

Abstract

The enigmatic origin of the proton-rich nuclei ^92 Mo and ^94 Mo in the solar system remains one of the most intriguing mysteries in astrophysics, with the definitive production site yet to be identified. Although mechanisms such as the proton-capture reactions, photonuclear reactions, and neutrino processes have been proposed, the underproduction of ^94 Mo persists as a puzzle. In this study, we investigate the production of ^94 Mo through neutrino-induced processes during core-collapse supernova explosions. By calculating the cross sections of the charged-current reactions ^94 Zr ( ν _e , e ^− ) ^94 Nb and ^95 Mo ( ν _e , e ^− p) ^94 Mo, as well as the neutral-current reactions ^95 Mo $\,(\nu ,{\nu }^{{\prime} }$ n) ^94 Mo, based on supernova explosion models, we explore the contribution of neutrino-nucleus reactions to the abundance of ^94 Mo. Our results indicate that these neutrino-induced reactions can account for up to 6.8% of the solar system abundance of ^94 Mo. Additionally, we propose that specific temperatures and proton number densities formed by neutrino shock waves could reproduce the solar system abundance ratio of ^94 Mo to ^92 Mo. This work provides a new perspective on understanding the origin of p -process nuclei in the solar system and establishes a significant theoretical foundation for future research endeavors.

Keywords

• Core-collapse supernovae
• Supernova neutrinos
• P-process
• Solar abundances