par Gaspard, David ;Sparenberg, Jean-Marc ;Wenda, Quentin;Baye, Daniel Jean
Référence Physical review. C. Nuclear physics, 100, 3, page (035805)
Publication Publié, 2019-09-27
Article révisé par les pairs
Résumé : An analysis of the astrophysical S factor of the proton-proton weak capture (p+p→2H+e++νe) is performed on a large energy range covering solar-core and early Universe temperatures. The measurement of S being physically unachievable, its value relies on the theoretical calculation of the matrix element Λ. Surprisingly, Λ reaches a maximum near 0.13MeV that has been unexplained until now. A model-independent parametrization of Λ valid up to about 5MeV is established on the basis of recent effective-range functions. It provides an insight into the relationship between the maximum of Λ and the proton-proton resonance pole at (−140−467i)keV from analytic continuation. In addition, this parametrization leads to an accurate evaluation of the derivatives of Λ, and hence of S, in the limit of zero energy.