Determination of the astrophysical S factor for 11C(p,γ)12N from the 12N→11C+p asymptotic normalization coefficient Academic Article uri icon


  • The evolution of very low-metallicity, massive stars depends critically on the amount of CNO nuclei that they produce. Alternative paths from the slow [Formula Presented] process to produce CNO seed nuclei could change their fate. The [Formula Presented] reaction is an important branch point in one such alternative path. At energies appropriate to stellar evolution of very low-metallicity, massive stars, nonresonant capture dominates the reaction rate. We have determined the astrophysical S factor for [Formula Presented] reaction using the asymptotic normalization coefficient for [Formula Presented] to fix the nonresonant capture rate. In our experiment, a 110 MeV [Formula Presented] radioactive beam was used to study [Formula Presented] peripheral transfer reaction and the asymptotic normalization coefficient, [Formula Presented] was extracted from the measured cross section. The contributions from the second resonance and interference effects were estimated using an R-matrix approach with the measured asymptotic normalization coefficient and the latest value for [Formula Presented] We find the S factor for [Formula Presented] is significantly larger than previous estimates. As a result, the required density for it to contribute is reduced, and more CNO material may be produced. © 2003 The American Physical Society.

author list (cited authors)

  • Tang, X., Azhari, A., Gagliardi, C. A., Mukhamedzhanov, A. M., Pirlepesov, F., Trache, L., ... Carstoiu, F.

citation count

  • 52

publication date

  • January 2003