New Study of the Astrophysical Reaction 12C(α,γ)16O via the 12C(7Li,t)16O Transfer Reaction

The 12C(α,γ)16O reaction plays an important role in helium burning in massive stars and their evolution. However, despite many experimental studies, the low‐energy cross section of 12C(α,γ)16O still highly uncertain. The extrapolation of the measured cross sections to stellar energies (E∼300 keV) is made difficult by the presence of the two sub‐threshold states at 6.92 and 7.12 MeV of 16O. In order to further investigate the contribution of these two‐subthreshold resonances to the 12C(α,γ)16O cross section, we performed a new determination of the α ‐reduced widths via a measurement of the transfer reaction 12C(7Li,t)16O at two incident energies, 34 and 28 MeV. The measured and calculated differential cross sections will be presented as well as the obtained spectroscopic factors and the α ‐reduced widths.