Experimentally constraining the $^{\mathrm{30}}$P(p,$\gamma )^{\mathrm{31}}$S reaction rate and its effect on nova nucleosynthesis*

Constraining the $^{\mathrm{30}}$P(p,$\gamma )^{\mathrm{31}}$S reaction is crucial for understanding ONe nova nucleosynthesis. Its rate influences the isotopic and chemical abundances of nova ejecta, particularly in the Si-Ca mass region, which may help identify presolar grains of putative nova origin. The reaction proceeds primarily through proton capture into narrow, isolated resonances at low energies. By determining the strengths of a few key resonances, we can substantially reduce reaction rate uncertainties. We report the results of a $^{\mathrm{31}}$Cl $\beta $-decay experiment in which we measured the very weak proton emission branch of a low-energy resonance using the GADGET. We calculated the total thermonuclear rate and determined this to be the dominant resonance in the reaction. We use hydrodynamic simulations to study this rate's effect on nuclear yields in classical nova ejecta.