Lowest excited states of ¹³O

An excitation function for resonance elastic scattering of p+¹²N was measured in the center of mass energy range of 0.8–2.7 MeV. Measurements were performed using inverse kinematics and the thick-target techniques. The data were analyzed in the framework of the R-matrix formalism. A definitive spin and parity assignment was possible for the first excited state of ¹³O at an excitation energy of 2.69 MeV as J^π=1/2⁺. An indication of the presence of a new level in ¹³O at an excitation energy of 3.29 MeV with tentative spin-parity assignment J^π=1/2^- or 3/2^- was obtained. We evaluate the impact of this measurement on the reaction rate of ¹²N(p,γ)¹³O for nucleosynthesis in low-metallicity stars.