Femtoscopic correlation functions between the lightest charmed hadrons

Femtoscopic momentum correlations probe low-energy interactions of short-lived charmed hadrons that are inaccessible to conventional scattering experiments. We calculate the correlation functions of $D^{+}{D}^{+}$, $D^0{D}^0$, $D^{+}{D}^0$, and ${\mathrm{\Lambda }}_c^{+}{\mathrm{\Lambda }}_c^{+}$ in Pb–Pb collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}=5.02$~TeV, using species-dependent non-Gaussian PHSD sources constructed from hadronization points and strong interactions calibrated to lattice-QCD scattering lengths: OBE and EFT-contact models for $DD$, and an EFT-contact model for ${\mathrm{\Lambda }}_c{\mathrm{\Lambda }}_c$. Coulomb and quantum-statistical effects are included consistently. Although the calibrated interactions are weakly repulsive, the channels separate the relevant effects: $D^{+}{D}^0$, free of Coulomb distortion and identical-particle interference, gives the cleanest access to the $DD$ strong interaction, whereas ${\mathrm{\Lambda }}_c^{+}{\mathrm{\Lambda }}_c^{+}$ is most pronounced in peripheral collisions, where the compact source enhances the low-momentum signal. The ${\mathrm{\Lambda }}_c{\mathrm{\Lambda }}_c$ input is taken from lattice QCD at a nonphysical pion mass, so its physical-point shift is not quantified here. Within these stated inputs, the results provide ALICE-ready benchmark correlations and background references; the quoted bands propagate only the lattice scattering-length uncertainty.