Production of p Nuclei from r-Process Seeds: The νr Process

Area of Science:

• Nuclear astrophysics
• Particle physics
• Cosmology

Background:

• The standard r-process explains the production of heavy elements through neutron captures and beta decays.
• Neutrino interactions in astrophysical environments are crucial for nucleosynthesis.
• The origin of p-nuclei remains a significant challenge in nuclear astrophysics.

Purpose of the Study:

• To introduce a novel nucleosynthesis process, the neutrino-driven r-process (νr process).
• To explore the potential of the νr process in producing neutron-deficient p-nuclei.
• To investigate the conditions required for the νr process in astrophysical sites.

Main Methods:

• Theoretical modeling of nucleosynthesis under intense neutrino flux.
• Comparison of reaction rates for neutron captures, beta decays, and neutrino absorption.
• Analysis of nuclear reaction networks in neutron-rich ejecta.

Main Results:

• The νr process utilizes charged-current neutrino absorption reactions that are faster than beta decays.
• This process can push neutron-rich nuclei beyond the beta stability line, forming p-nuclei.
• The νr process provides a potential production channel for p-nuclei and ^{92}Nb.

Conclusions:

• The νr process offers an alternative pathway for p-nuclei and ^{92}Nb production.
• Current astrophysical models do not fully support the conditions for the νr process.
• Future advanced models may reveal astrophysical sites where the νr process can occur.