Parametric Study of Proton-Capture Nucleosynthesis of 27Al via the Extended Ne – Al Chain

We present a parametric investigation of proton-capture reactions within the extended Neon–Sodium–Magnesium–Aluminum (Ne–Al) nuclear reaction network, with particular emphasis on the production of ²⁷ Al. The study explores the sensitivity of aluminum synthesis to temperature conditions in the range T ₉ = 0.02–0.10 at a fixed density of 100 g cm ^-3 . The calculations are performed using a single-zone nuclear reaction network with simplified initial abundance assumptions, including an idealized uniform distribution of selected isotopes to probe reaction pathways. The nuclear network is solved numerically to obtain the evolution and quasi-equilibrium mass fractions of the involved species. The results demonstrate that the extended chain Ne - Al can efficiently produce ²⁷ Al within the temperature range explored, with the final abundances showing a systematic dependence on the temperature and reaction flow characteristics. A statistical comparison with representative observational abundance datasets yields a correlation coefficient exceeding 0.85 and a mean absolute deviation (MAD) of 0.40 dex, indicating that the model captures general abundance trends despite its simplified assumptions. This work does not incorporate a full stellar evolution model or transport processes such as mixing and diffusion. Therefore, the results should be interpreted as indicative of nuclear reaction pathways and sensitivities,rather than direct predictions of stellar surface abundances. The study provides insight into the role of proton-capture processes in shaping intermediate-mass element synthesis under controlled thermodynamic conditions.