Precise resonance parameter measurement in the 12C(p,γ)13N astrophysically important reaction

Precise knowledge of the 12C(p,γ)13N reaction cross section is crucial to understand the evolution of various types of red giant stars and to explain their astronomically observed surface 12C/13C abundance ratio. Experimental data show discordance near resonances below Ep=2000 keV. Dedicated measurements using in-beam γ-spectroscopy have been carried out in the vicinity of Ep=460 and 1700 keV to obtain resonance parameters, such as the resonance energy and width. Using a simplified R-matrix model, the following values of resonance energy and width were obtained: Er=459.8±0.8; Γtotal= 38.2±0.5 keV and Er=1685.1±0.7; Γtotal=57.6±0.8 keV given in laboratory system. These values with reduced uncertainties provide new input parameters for future compilations of 12C(p,γ)13N reaction and thus for astrophysics cross-section extrapolations.