Theoretical evaluation of solar proton-proton fusion reaction rate and its uncertainties

Understand

The weak proton-proton fusion into a deuteron ($^2$H) is the driving reaction in the energy production in the Sun, as well as similar main sequence stars.

• Its reaction rate in the solar interior is determined only theoretically.
• Here, we provide a new determination of the rate of this reaction in solar conditions $S^{11}(0)$, and analyze theoretical and experimental sources for uncertainties, using effective field theory of quantum chromo-dynamics without explicit pions at next-to-leading order.
• We find an enhancement of $S^{11}$ by $1-4\%$ over the previously recommended value.