Experimental Determination of α Widths of ^{21}Ne Levels in the Region of Astrophysical Interest: New ^{17}O+α Reaction Rates and Impact on the Weak s Process.

The efficiency of the weak s process in low-metallicity rotating massive stars depends strongly on the rates of the competing ^{17}O(α,n)^{20}Ne and ^{17}O(α,γ)^{21}Ne reactions that determine the potency of the ^{16}O neutron poison. Their reaction rates are poorly known in the astrophysical energy range of interest for core helium burning in massive stars because of the lack of spectroscopic information (partial widths, spin parities) for the relevant states in the compound nucleus ^{21}Ne. In this Letter, we report on the first experimental determination of the α-particle spectroscopic factors and partial widths of these states using the ^{17}O(^{7}Li,t)^{21}Ne α-transfer reaction.

Publisher Correction: An increase in the C + C fusion rate from resonances at astrophysical energies.

In equation (1) of this Letter, the closing bracket was missing; in Extended Data Fig. 1 and the accompanying legend, 'Φ(p)' should have been 'Φ(p)', and in the Methods the text "Odd J assignments are uncertain by ±1." has been added.

An increase in the C + C fusion rate from resonances at astrophysical energies.

Carbon burning powers scenarios that influence the fate of stars, such as the late evolutionary stages of massive stars (exceeding eight solar masses) and superbursts from accreting neutron stars. It proceeds through the C + C fusion reactions that produce an alpha particle and neon-20 or a proton and sodium-23-that is, C(C, α)Ne and C(C, p)Na-at temperatures greater than 0.4 × 10 kelvin, corresponding to astrophysical energies exceeding a megaelectronvolt, at which such nuclear reactions are more likely to occur in stars.

High-Precision Probe of the Fully Sequential Decay Width of the Hoyle State in ^{12}C.

The decay path of the Hoyle state in ^{12}C (E_{x}=7.654  MeV) has been studied with the ^{14}N(d,α_{2})^{12}C(7.654) reaction induced at 10.

Measurement of the -3 keV resonance in the reaction 13C(α,n)16O of importance in the s-process.

The (13)C(α,n)(16)O reaction is the neutron source for the main component of the s-process, responsible for the production of most nuclei in the mass range 90 View Article and Find Full Text PDF