Impact of the experimental mass of 70Kr on the 68Se waiting point in the rp process

The recent mass measurement of ⁷⁰Kr using the Bρ-defined isochronous mass spectrometry yields a mass excess of −41320(140) keV, indicating a 220-keV increase in binding energy compared to the AME2020 prediction. We utilize this experimental mass—the last piece of information needed—to model the potential waiting point ⁷⁰Se in rp process and quantitatively constrain the sequential p-capture reaction flow bypassing this waiting point. Our investigation shows that the more tightly bound nature of ⁷⁰Kr enhances this reaction flow up to a factor of four. This enhancement reduces the effective half-life of ⁶⁸Se. A one-zone x-ray burst-model calculations reveal that the higher flow of ⁷⁰Kr has distinct effects on the tail structure of light curve and the final SnSbTe abundances in the ashes due to a stronger rp-process heating.