Toward a reassessment of the 19F(p, α0α0)16O reaction rate at astrophysical temperatures

The 19F(p, α0α0)16O reaction at low energies plays an important role in fundamental physics. In particular in nuclear astrophysics it represents, together with the 19F(p, γ)20Ne reaction, the crossing point between the CNO and the NeNa cycles in stars. Further, in hydrogen-rich stellar environments, it is the most important fluorine destruction channel. In this paper we report new measurements on the 19F(p, α0α0)16O reaction at deeply sub-Coulomb energies (0.2–0.6 MeV), a region where, despite the key role of this reaction, very few and old data are reported. The deduced astrophysical S  -factor is ≈1.5–2≈1.5–2 times larger than currently adopted extrapolations with possibly important astrophysical consequences.