Enhanced Semi-empirical Formulation for (\(p,n\)) Cross Sections at 12.4 MeV

In this study, we present an improved formulation for calculating (\(p,n\)) reaction cross sections at a proton energy of 12.4 MeV. This new approach is based on updated experimental data (EXFOR 2026), a revised compilation of non-elastic cross sections using the TALYS nuclear reaction code, and a re-evaluation of the empirical adjustment parameters. The proposed model builds upon the work of Broeders and Konobeyev (2008) and integrates key theoretical elements of the compound nucleus regime, including the semi-empirical mass formula and the statistical evaporation model. Comparisons with TALYS calculations, which include both statistical and pre-equilibrium contributions, demonstrate the validity of our approach at 12.4 MeV, where compound nucleus mechanisms dominate. The revised six-parameter formulation demonstrates excellent agreement with the latest experimental data and yields significantly reduced values for the statistical deviation metrics \({ Σ }\) and \(χ ^2\). This work contributes to the refinement of nuclear reaction models and provides a reliable tool for cross-section prediction in applied and fundamental nuclear science. Abstract Published by the Jagiellonian University 2026 authors