Analyzing power measurement for the ¹⁴N(→p, γ) ¹⁵O reaction at astrophysically relevant energies

The ¹⁴N(→p, γ)¹⁵O reaction has been investigated by measuring the angular distributions of its cross section and analyzing power using a 270-keV polarized proton beam. Calculations using a direct-capture-plus-resonance model were compared with the data. The results indicate the presence of γ transition amplitudes which were not considered in previous extrapolations of the astrophysical S factor to low energies. The impact on the zero-energy S factor of the ¹⁴N(→p, γ)¹⁵O reaction is discussed.