The $E1$ component of the $\gamma$-ray strength function of ${}^{72}\mathrm{Ga}$ nuclei has been constrained for the first time through a statistical Hauser-Feshbach analysis of the available capture data for the ${}^{71}\mathrm{Ga}(n,\gamma ){}^{72}\mathrm{Ga}$ reaction over the neutron energy range of 0.01–3 MeV. The analysis employs the nuclear level density (NLD) of ${}^{72}\mathrm{Ga}$ constrained by the work of Santra et al. [Phys. Rev. C 107, 064611 (2023)]. In the present analysis, the Gogny D1M $\mathrm{HFB}+\mathrm{QRPA}$ model is adopted for the $E1$ and $M1$ strength functions, including the low-energy upbend. The normalization of the Gogny D1M $\mathrm{HFB}+\mathrm{QRPA}$ model for the $E1$ component has been constrained in the present work, as a clear minimum is obtained. However, the upbend parameters are not constrained, as no well-defined chi-square (${\chi }^2$) minimum is found for these parameters within physically motivated bounds. The extracted $\gamma$-ray strength function of ${}^{72}\mathrm{Ga}$ is compared with experimental data for the neighboring nuclei ${}^{73,74}\mathrm{Ge}$, exhibiting similar trends. The constrained $\gamma$-ray strength function is then used to calculate the Maxwellian-averaged cross section (MACS) at $kT=30$ keV as a consistency check of the present analysis.

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• Gamma-ray strength functions
• Nuclear astrophysics
• Nuclear reactions
• Nucleon induced nuclear reactions
• Radiative capture
• s process
• 59 ≤ A ≤ 89
• Thermal & statistical models