Coulomb corrections to the three-nucleon electroweak form factors towards a more precise proton-proton fusion prediction

In this talk, I will discuss the Coulomb corrections to the three-nucleon electroweak form factors to order α in the fine structure constant. Given the relatively large binding energies of three-nucleon systems, Coulomb effects can be treated perturbatively (αM_N << p* where p* is the three-nucleon binding momentum). We calculated the charge and magnetic moment of ³He at next-to-leading-order (NLO) in pionless effective field theory (EFT) with Coulomb corrections, then compared with the experimental values. We also computed the Gamow-Teller and Fermi matrix elements for the triton β-decay process. Triton β-decay and proton-proton fusion both depend on the same undetermined low-energy constant at NLO in pionless EFT. We extracted this low-energy constant from the triton β-decay half-life to obtain a more precise prediction for the proton-proton fusion rate, which is crucial for understanding stellar nucleosynthesis.