(Left) Source radius $r_\mathrm 0$ as a function of $\langle\mt\rangle$ for the assumption of a purely Gaussian source. (Right) Source radius $r_{\mathrm{core}}$ as a function of $\langle\mt\rangle$ for the assumption of a Gaussian source with added resonances. The blue crosses result from fitting the \pP correlation function with the strong Argonne $v_{18}$  potential. The green squared crosses (red diagonal crosses) result from fitting the \pL correlation functions with the strong $\chi$EFT LO  (NLO ) potential. Statistical and systematic uncertainties are indicated by vertical bars and boxes, respectively .