We report the first measurement of ${}^{115}\mathrm{Sn}(p,\gamma ){}^{116}\mathrm{Sb}$ cross sections using the activation technique in the beam energy range of 2.5–6.0 MeV, covering nearly the entire Gamow window relevant to the $p$-process nucleosynthesis of ${}^{115}\mathrm{Sn}$. Cross sections for both the ground and metastable states of ${}^{116}\mathrm{Sb}$ were determined, and the corresponding astrophysical S factors were extracted. After correcting for electron screening effects, the screened cross sections and S factors were compared with Hauser-Feshbach statistical model predictions. talys calculations with default input parameters reproduce the screened data reasonably well, while non-smoker predictions show significant deviations. Stellar reaction rates were calculated using the default talys inputs and compared with rates from the JINA REACLIB database for both the forward ${}^{115}\mathrm{Sn}(p,\gamma ){}^{116}\mathrm{Sb}$ and the inverse ${}^{116}\mathrm{Sb}(\gamma ,p){}^{115}\mathrm{Sn}$ reactions. These rates will provide valuable constraints toward resolving the long-standing debate on the $p$-process contribution to the solar abundance of ${}^{115}\mathrm{Sn}$.

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• Nuclear astrophysics
• Nuclear reactions
• Radiative capture
• S-factor
• 90 ≤ A ≤ 149