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

Background: Accurate knowledge of the ${}^{13}$C($\alpha$,$n$)${}^{16}$O reaction cross section is important for the understanding of the s-process in AGB stars, since it is considered to be the main source of neutrons. The sub-threshold 1/2${}^{+}$ state at excitation energy of 6.356 MeV in ${}^{17}$O has a strong influence on the reaction cross section at energies relevant for astrophysics. Several experiments have been performed to determine the contribution of this state to the ${}^{13}$C($\alpha ,n{)}^{16}$O reaction rate. Nevertheless, significant discrepancies between different measurements remain. Purpose: The aim of this work is to investigate these discrepancies. Method: An 8 MeV ${}^{13}$C beam (below the Coulomb barrier) was used to study the $\alpha$-transfer reaction ${}^6$Li(${}^{13}$C,$d$)${}^{17}$O. Results: The squared Coulomb modified ANC of the 1/2${}^{+}$ state in ${}^{17}$O measured in this work is $(\tilde C^{^{17}$\text{O}$(1/2+)}_{\alpha-^{13}$\text{C}$})^2=3.6\pm0.7\hspace{0.2cm}$\text{fm}$^{-1}$. Conclusions: Discrepancy between the results of $\alpha$-transfer experiments have been resolved. However, some discrepancy with the most recent measurement using the Trojan Horse method remains.