$^{94}$Mo($\gamma $,n) and $^{90}$Zr($\gamma $,n) cross-section measurements towards understanding the origin of $p$-nuclei

The nucleosynthesis beyond iron of the rarest stable isotopes in the cosmos, the so-called $p$-nuclei, is one of the forefront topics in nuclear astrophysics. Recently, a stellar source was found that, for the first time, was able to produce both light and heavy $p$-nuclei almost at the same level as $^{56}$Fe, including the most debated $^{92,94}$Mo and $^{96,98}$Ru; it was also found that there is an important contribution from the $p$-process nucleosynthesis to the neutron magic nucleus $^{90}$Zr [1]. We focus here on constraining the origin of $p$-nuclei through nuclear physics by studying two key astrophysical photoneutron reaction cross sections for $^{94}$Mo($\gamma $,n) and $^{90}$Zr($\gamma $,n). Their energy dependencies were measured using quasi-monochromatic photon beams from Duke University's High Intensity Gamma-ray Source facility at the respective neutron threshold energies up to 18 MeV. Preliminary results of these experimental cross sections will be presented along with their comparison to predictions by a statistical model based on the Hauser-Feshbach formalism implemented in codes like TALYS and SMARAGD. \\[4pt] [1] C. Travaglio, \textit{et. al.}, ApJ 739 (2011) 93.