Tritium ${\hat{I}}^2$-decay and Proton-Proton Fusion in Pionless Effective Field Theory

Ha S. Nguyen, Jared Vanasse

The Gamow-Teller and Fermi matrix elements, $⟨\mathbf{GT}⟩$ and $⟨\mathbf{F}⟩$, respectively, for tritium ${\hat{I}}^2$-decay are calculated to next-to-leading ord…