6533b7d6fe1ef96bd12659a4

RESEARCH PRODUCT

C15 : From halo effective field theory structure to the study of transfer, breakup, and radiative-capture reactions

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Background: Aside from being a one-neutron halo nucleus, $^{15}\mathrm{C}$ is interesting because it is involved in reactions of relevance for several nucleosynthesis scenarios.Purpose: The aim of this work is to analyze various reactions involving $^{15}\mathrm{C}$, using a single structure model based on halo effective field theory (halo EFT) following the excellent results obtained in [P. Capel et al., Phys. Rev. C 98, 034610 (2018)].Method: To develop a halo-EFT model of $^{15}\mathrm{C}$ at next to leading order (NLO), we first extract the asymptotic normalization coefficient (ANC) of its ground state by analyzing $^{14}\mathrm{C}(d,p)^{15}\mathrm{C}$ transfer data at low energy using the method developed in [J. Yang and P. Capel, Phys. Rev. C 98, 054602 (2018)]. Using the halo-EFT description of $^{15}\mathrm{C}$ constrained with this ANC, we study the $^{15}\mathrm{C}$ Coulomb breakup at high (605 MeV/nucleon) and intermediate (68 MeV/nucleon) energies using eikonal-based models with a consistent treatment of nuclear and Coulomb interactions at all orders, and which take into account proper relativistic corrections. Finally, we study the $^{14}\mathrm{C}(n,\ensuremath{\gamma})^{15}\mathrm{C}$ radiative capture.Results: Our theoretical cross sections are in good agreement with experimental data for all reactions, thereby assessing the robustness of the halo-EFT model of this nucleus. Since a simple NLO description is enough to reproduce all data, the only nuclear-structure observables that matter are the $^{15}\mathrm{C}$ binding energy and its ANC, showing that all the reactions considered are purely peripheral. In particular, it confirms the value we have obtained for the ANC of the $^{15}\mathrm{C}$ ground state: ${\mathcal{C}}_{1/{2}^{+}}^{2}=1.59\ifmmode\pm\else\textpm\fi{}0.06\phantom{\rule{4pt}{0ex}}{\mathrm{fm}}^{\ensuremath{-}1}$. Our model of $^{15}\mathrm{C}$ provides also a new estimate of the radiative-capture cross section at astrophysical energy: ${\ensuremath{\sigma}}_{n,\ensuremath{\gamma}}(23.3\phantom{\rule{0.16em}{0ex}}\mathrm{keV})=4.66\ifmmode\pm\else\textpm\fi{}0.14\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{b}$.Conclusions: Including a halo-EFT description of $^{15}\mathrm{C}$ within precise models of reactions is confirmed to be an excellent way to relate the reaction cross sections and the structure of the nucleus. Its systematic expansion enables us to establish how the reaction process is affected by that structure and deduce which nuclear-structure observables are actually probed in the collision. From this, we can infer valuable information on both the structure of $^{15}\mathrm{C}$ and its synthesis through the $^{14}\mathrm{C}(n,\ensuremath{\gamma})^{15}\mathrm{C}$ radiative capture at astrophysical energies.