Measurement of the branching ratio for beta-delayed alpha decay of 16N

Abstract

While the 12C(a,g)16O reaction plays a central role in nuclear astrophysics, the cross section at energies relevant to hydrostatic helium burning is too small to be directly measured in the laboratory. The beta-delayed alpha spectrum of 16N can be used to constrain the extrapolation of the E1 component of the S-factor; however, with this approach the resulting S-factor becomes strongly correlated with the assumed beta-alpha branching ratio. We have remeasured the beta-alpha branching ratio by implanting 16N ions in a segmented Si detector and counting the number of beta-alpha decays relative to the number of implantations. Our result, 1.49(5)e-5, represents a 24% increase compared to the accepted value and implies an increase of 14% in the extrapolated S-factor.

References in corpus (6)

• Nucleosynthesis and Remnants in Massive Stars of Solar Metallicity
• Constraining the 6.05 MeV 0${}^{+}$ and 6.13 MeV 3${}^{-}$ cascade transitions in the ${}^{12}$C($\alpha$,$\gamma$)${}^{16}$O reaction using the Asymptotic Normalization Coefficients
• Beta-delayed deuteron emission from 11Li: decay of the halo
• Energy Deconvolution of Cross Section Measurements with an Application to the 12C(α,γ)16O Reaction
• Ambiguities of the Rate of Oxygen Formation During Stellar Helium Burning in the 12C(a,g) Reaction
• Effective Helium Burning Rates and the Production of the Neutrino Nuclei

Cited by in corpus (5)

• The 12C(a,g)16O reaction and its implications for stellar helium burning
• On the phase-shift parameterization and ANC extraction from elastic-scattering data
• Clarification of large-strength transitions in the beta decay of 11Be
• Astrophysical $S_{E2}$ factor of the ${}^{12}\mathrm{C}(\alpha ,\gamma ){}^{16}\mathrm{O}$ reaction through the ${}^{12}\mathrm{C}({}^{11}\mathrm{B},{}^7\mathrm{Li}){}^{16}\mathrm{O}$ transfer reaction
• First Accurate Normalization of the $\beta$-delayed $\alpha$ Decay of ${}^{16}$N and Implications for the ${}^{12}$C$(\alpha ,\gamma {)}^{16}$O Astrophysical Reaction Rate