This article presents the first measurement of the interaction between charm hadrons and nucleons. The two-particle momentum correlations of $\mathrm{p}{\mathrm{D}}^{-}$ and ${\overline{\mathrm{p}}\mathrm{D}}^{+}$ pairs are measured by the ALICE Collaboration in high-multiplicity pp collisions at $\sqrt{s}=13\mathrm{TeV}$. The data are compatible with the Coulomb-only interaction hypothesis within $(1.1–1.5)\sigma$. The level of agreement slightly improves if an attractive nucleon $(\mathrm{N})\overline{\mathrm{D}}$ strong interaction is considered, in contrast to most model predictions which suggest an overall repulsive interaction. This measurement allows for the first time an estimation of the 68% confidence level interval for the isospin $\mathrm{I}=0$ inverse scattering length of the $\mathrm{N}\overline{\mathrm{D}}$ state $f_{0,\mathrm{I}=0}^{-1}\in [-0.4,0.9]{\mathrm{fm}}^{-1}$, assuming negligible interaction for the isospin $\mathrm{I}=1$ channel.

• Received 27 January 2022
• Revised 3 May 2022
• Accepted 31 August 2022
• Corrected 1 November 2022

DOI:https://doi.org/10.1103/PhysRevD.106.052010

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