Concurrent application of ANC and THM to assess the ${}^{13}\mathrm{C}(\alpha ,n{)}^{16}\mathrm{O}$ absolute cross section at astrophysical energies and possible consequences for neutron production in low-mass AGB stars

Abstract

The ${}^{13}\mathrm{C}(\alpha ,n{)}^{16}\mathrm{O}$ reaction is considered to be the main neutron source responsible for the production of heavy nuclides (from $\mathrm{Sr}$ to $\mathrm{Bi}$) through slow $n$-capture nucleosynthesis ($s$-process) at low temperatures during the asymptotic giant branch (AGB) phase of low mass stars ($\lesssim 3-4{\mathrm{M}}_{\odot }$, or LMSs). In recent years, several direct and indirect measurements have been carried out to determine the cross section at the energies of astrophysical interest (around $190\pm 40\mathrm{keV}$). However, they yield inconsistent results causing a highly uncertain reaction rate and affecting the neutron release in LMSs. In this work we have combined two indirect approaches, the asymptotic normalization coefficient (or ANC) and the Trojan Horse Method (THM), to unambiguously determine the absolute value of the ${}^{13}\mathrm{C}(\alpha ,n{)}^{16}\mathrm{O}$ astrophysical factor. Therefore, we have determined a very accurate reaction rate to be introduced into astrophysical models of $s$-process nucleosynthesis in LMSs. Calculations using such recommended rate have shown limited variations in the production of those neutron-rich nuclei (with $86\le A\le 209$) receiving contribution only by slow neutron captures.

References in corpus (4)

• Can Extra Mixing in RGB and AGB Stars Be Attributed to Magnetic Mechanisms?
• New determination of the 13C(a, n)16O reaction rate and its influence on the s-process nucleosynthesis in AGB stars
• s-Processing in AGB Stars Revisited. I. Does the Main Component Constrain the Neutron Source in the 13C-Pocket?
• New $\alpha$ ANC measurement of the 1/2${}^{+}$ state in ${}^{17}$O at 6.356 MeV, that dominates the ${}^{13}$C($\alpha$,n)${}^{16}$O reaction rate at temperatures relevant for the s-process

Cited by in corpus (6)

• LUNA: Status and Prospects
• Direct measurement of the 13C(α,n)16O cross section into the s-process Gamow peak
• Magnetic-buoyancy-induced mixing in AGB Stars: fluorine nucleosynthesis at different metallicities
• Deep underground laboratory measurement of ${}^{13}$C($\alpha$,$n$)${}^{16}$O in the Gamow windows of the $s$- and $i$-processes
• The study of key reactions shaping the post main-sequence evolution of massive stars in underground facilities
• Underground Measurements of Nuclear Reaction Cross-Sections Relevant to AGB Stars