New constraints on radiative decay of long-lived particles in big bang nucleosynthesis with new {sup 4}He photodisintegration data
- Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan)
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan)
- Institute of Advanced Energy, Kyoto University, Gokasyo, Uji, Kyoto 611-0011 (Japan)
A recent measurement of {sup 4}He photodisintegration reactions, {sup 4}He({gamma},p){sup 3}H and {sup 4}He({gamma},n){sup 3}He with laser-Compton photons shows smaller cross sections than those estimated by other previous experiments at E{sub {gamma}} < or approx. 30 MeV. We study big bang nucleosynthesis with the radiative particle decay using the new photodisintegration cross sections of {sup 4}He as well as previous data. The sensitivity of the yields of all light elements D, T, {sup 3}He, {sup 4}He, {sup 6}Li, {sup 7}Li, and {sup 7}Be to the cross sections is investigated. The change of the cross sections has an influence on the nonthermal yields of D, {sup 3}He, and {sup 4}He. On the other hand, the nonthermal {sup 6}Li production is not sensitive to the change of the cross sections at this low energy, since the nonthermal secondary synthesis of {sup 6}Li needs energetic photons of E{sub {gamma}} > or approx. 50 MeV. The nonthermal nucleosynthesis triggered by the radiative particle decay is one of candidates of the production mechanism of {sup 6}Li observed in metal-poor halo stars. In the parameter region of the radiative particle lifetime and the emitted photon energy, which satisfies the {sup 6}Li production above the abundance level observed in metal-poor halo stars, the change of the photodisintegration cross sections at E{sub {gamma}} < or approx. 30 MeV as measured in the recent experiment leads to {approx}10% reduction of resulting {sup 3}He abundance, whereas the {sup 6}Li abundance does not change for this change of the cross sections of {sup 4}He({gamma},p){sup 3}H and {sup 4}He({gamma},n){sup 3}He. The {sup 6}Li abundance, however, could show a sizable change and therefore the future precise measurement of the cross sections at high energy E{sub {gamma}} > or approx. 50 MeV is highly required.
- OSTI ID:
- 21300944
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 79, Issue 12; Other Information: DOI: 10.1103/PhysRevD.79.123513; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
Similar Records
Mechanism of the reaction. gamma. +/sup 6/Li. -->. p+d+t
Particle Physics Catalysis of Thermal Big Bang Nucleosynthesis