Background: This work presents a study of the combined influence of nuclear deformation and nonlocality on cross sections of 20 $(\alpha ,n)$ reactions relevant to $\gamma$-process nucleosynthesis in the mass range $69\le A\le 197$. Earlier works employing the TALYS global $\alpha –\mathrm{OMP}$ reproduced data trends using a nine-parameter potential that captures broad systematics but omits deformation and nonlocality. The present study evaluates how the explicit inclusion of these effects impacts the predictive performance of semimicroscopic models.

Purpose: The purpose of this work is to investigate, within a unified and physically motivated framework, the combined influence of nuclear deformation and nonlocality on $(\alpha ,n)$ reaction cross sections relevant to $p$-process nucleosynthesis and to assess their role in achieving quantitative agreement with experimental data.

Methods: We extend a previously developed semimicroscopic $\alpha$-nucleus optical model potential ($\alpha –\mathrm{OMP}$) based on a double-folding real interaction supplemented with a repulsive core. Nuclear deformation is included through couplings to collective states using ${\beta }_2$ and ${\beta }_4$ deformation parameters, while Pauli-type nonlocality is modeled with a Gaussian Perey–Buck kernel. Systematic calculations are performed using this framework for 20 $(\alpha ,n)$ reactions.

Results: Nuclear deformation is found to significantly reduce the Coulomb barrier and enhance sub-barrier reaction probabilities, particularly for well-deformed nuclei. The inclusion of nonlocality further refines the wave-function profile and improves the agreement with experimental cross sections. The best performance is obtained when both deformation and nonlocality are included simultaneously, yielding the lowest deviations across the nuclear chart.

Conclusions: The analysis indicates that nuclear deformation and nonlocality contribute meaningfully to the description of $(\alpha ,n)$ reactions at astrophysical energies. Their combined treatment leads to improved physical consistency and predictive performance relative to global parametrizations. This framework thus represents a constructive step toward structure-informed $\alpha –\mathrm{OMP}$ developments for future astrophysical applications.

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• H & He induced nuclear reactions
• Nuclear astrophysics
• Nuclear reactions
• Nuclear structure & decays
• Transfer reactions