Are spectroscopic factors from transfer reactions consistent with asymptotic normalization coefficients?

It is extremely important to devise a reliable method to extract spectroscopic factors from transfer cross sections. We analyze the standard DWBA procedure and combine it with the asymptotic normalization coefficient, extracted from an independent data set. We find that the single particle parameters used in the past generate inconsistent asymptotic normalization coefficients. In order to obtain a consistent spectroscopic factor, nonstandard parameters for the single particle overlap functions can be used but, as a consequence, often reduced spectroscopic strengths emerge. Different choices of optical potentials and higher order effects in the reaction model are also studied. Our test cases consist of ¹⁴C(d,p)¹⁵C(g.s.) at E_d^lab=14 MeV, ¹⁶O(d,p)¹⁷O(g.s.) at E_d^lab=15 MeV and ⁴⁰Ca(d,p)⁴¹Ca(g.s.) at E_d^lab=11 MeV. We underline the importance of performing experiments specifically designed to extract asymptotic normalization coefficients for these systems.