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The impact of nuclear uncertainties on the p -process nucleosynthesis in supernovae

par Martinet, Sebastién;Goriely, Stéphane ;Choplin, Arthur
Référence Astronomy & astrophysics, 713, page (A49)
Publication Publié, 2026-09-10

Article révisé par les pairs

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Résumé :

Context. Typically, p -process nucleosynthesis is called on to explain the origin of the stable neutron-deficient nuclides heavier than iron that have exclusively been observed in the Solar System thus far. Our understanding of the p -process nucleosynthesis is still affected by relatively large nuclear uncertainties. One of the significant uncertainties in determining the ejecta composition stems from the nuclear level densities and photon strength functions entering the calculation of the photodisintegrations of relevance in the high-temperature environment characterizing supernova explosions. Aims. We investigate both the model (systematic) and parameter (statistical) uncertainties affecting nuclear level densities and photon strength functions. We explore their impact on the p -process nucleosynthesis in type-Ia and type-II supernovae. Methods. We estimated the impact of correlated model uncertainties affecting nuclear level densities and photon strength functions by considering different models known to provide an accurate description of previously determined related observables. In addition, the uncorrelated uncertainties associated with local variations in the model parameters can be estimated using a variant of the backward-forward Monte Carlo (BFMC) method to constrain the parameter changes to experimentally known rates before propagating them consistently to the unknown cross sections of neutron-deficient nuclei. Both the model and parameter uncertainties associated with nuclear level densities and photon strength functions were propagated to the p -process nucleosynthesis by taking existing correlations into account. To identify which reactions most strongly control the abundance uncertainties of the p-nuclides, we combined regularized linear-response modeling and stability analysis, along with contribution and interaction decompositions. Results. We find that the uncorrelated parameter uncertainties affecting the photoneutron emission strongly dominate the uncertainty budget. The dominant source of uncertainty arises from the range of local parameter variations that are still allowed by the present experimental constraints. Consequently, the main limitation at present is the lack of sufficiently constraining nuclear data in the relevant neutron-deficient region. For a large fraction of the p-nuclei, the governing uncertainties are found to be originating from either the photoneutron emission of the p-nucleus itself or the ( γ ,  n ) reaction on a nearby isotope along the same isotopic chain. Conclusions. Improvements to nuclear models are still crucial in reducing uncertainties on predictions related to the p -process nucleosynthesis. Many of the key reactions identified as dominant drivers correspond to stable or near-stable nuclei and, in several cases, to the photodisintegration of the p-nuclei themselves. A substantial fraction of the reactions controlling the p -process abundance uncertainties should (at least in principle) be experimentally accessible through direct measurements.