Evidence of E1 excited states in 19F from the (γ, t) reaction2

The ¹⁹F(γ, t)¹⁶O reaction was studied over an energy region of 18 to 23 MeV. Two resonances were observed at 18.8 MeV and 20.1 MeV. The angular distribution of tritons from these resonances indicated that the tritons are emitted predominantly in a p-wave, implying $\text{j}{}^{\mathrm{\pi }}\text{=}\text{1}\text{2}$^?, or $\text{3}\text{2}$^? with T = $\text{1}\text{2}$ for both levels. A comparison with other experiments i the states could be attributed to ¹⁶O+t cluster configurations. In addition, from the measured ratio σ(γ, α)/σ(γ, t) ? 0.01 it is concluded that the formation of ¹⁵N+α cluster states is small in this region of excitation.