Naslov
Thermonuclear F-19(p, alpha(0))O-16 reaction rate

Autori
He, Jian-Jun ; Lombardo, Ivano ; Dell’Aquila, Daniele ; Xu, Yi ; Zhang, Li-Yong ; Liu, Wei-Ping

Izvornik
Chinese Physics C (1674-1137) 42 (2018), 1; 015001, 11

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Nuclear structure ; nuclear astrophysics

Sažetak
The thermonuclear 19F(p, α0)16O reaction rate in the temperature region 0.007-10 GK has been derived by re-evaluating the available experimental data, together with the low-energy theoretical R-matrix extrapolations. Our new rate deviates by up to about 30% compared to the previous results, although all rates are consistent within the uncertainties. At very low temperature (e.g. 0.01 GK) our reaction rate is about 20% lower than the most recently published rate, because of a difference in the low energy extrapolated S-factor and a more accurate estimate of the reduced mass used in the calculation of the reaction rate. At temperatures above ∼1 GK, our rate is lower, for instance, by about 20% around 1.75 GK, because we have re- evaluated the previous data (Isoya et al., Nucl. Phys. 7, 116 (1958)) in a meticulous way. The present interpretation is supported by the direct experimental data. The uncertainties of the present evaluated rate are estimated to be about 20% in the temperature region below 0.2 GK, and are mainly caused by the lack of low-energy experimental data and the large uncertainties in the existing data. Asymptotic giant branch (AGB) stars evolve at temperatures below 0.2 GK, where the 19F(p, α0)16O reaction may play a very important role. However, the current accuracy of the reaction rate is insufficient to help to describe, in a careful way, the fluorine over- abundances observed in AGB stars. Precise cross section (or S factor) data in the low energy region are therefore needed for astrophysical nucleosynthesis studies.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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