Low-energy resonances in the 22Ne(p,γ)23Na reaction directly observed at LUNA

The 22Ne(p,γ)23Na reaction is involved in the hydrogen burning neon-sodium (NeNa) cycle. This cycle is active in asymptotic giant branch stars (AGB) as well as in novae. In the Gamow window temperature range (30MK< T < 420MK corresponding to proton center of mass energies 40 keV < E < 430 keV), the 22Ne(p,γ)23Na reaction rate is highly uncertain because of the contribution of a large number of resonances never measured directly. A study of this reaction has been carried out at the Laboratory for Underground Nuclear Astrophysics (LUNA), in the Gran Sasso National Laboratory, using a windowless gas target and two high-purity germanium detectors. Several resonances have been observed for the first time in a direct experiment.