Probing and Raising the Lithium Problems With Hadronic Gamma Rays and Cosmic -Ray Nucleosynthesis

"Besides lithium, CRs also produce ""pionic"" gamma-rays through pp → pi0 → gammagamma. Thus there is an intimate link between Li and gamma-rays produced in CR interactions. In this thesis we explore this link and use it as a new, model-independent way of testing the CR nucleosynthesis of Li. We apply this tool to test a, still hypothetical, cosmological CR population. Moreover, our approach reveals yet another Li problem. The isotope 6Li is made only in CR interactions where the standard assumption is that the measured solar 6Li abundance originated from interactions of galactic cosmic-rays (GCRs) with the interstellar medium. However, by applying our tool on this fiducial case, we found that gamma-ray observations allow for only ≈ 60% of the solar 6Li abundance to be produced by standard GCRs. This result bears important consequences for the non-standard sources of 6Li nucleosynthesis such as decaying dark matter and low-energy cosmic-ray component."

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Astronomy

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2006

Author dc:creator

• Prodanovic, Tijana S.

Contributors dc:contributor

• Fields, Brian D.

• Physics, Astronomy and Astrophysics

Language dc:language

eng

Identifier

(MiAaPQ)AAI3242964

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/85183