Extracting properties of the 𝑻 𝒄𝒄 state from lattice QCD

A brief overview of the properties of the exotic state $T_{cc}$, as extracted from the LHCb data and lattice QCD simulations using chiral effective field theory ($\chi$EFT), is presented. We demonstrate that explicit account for the longest-range one-pion exchange interaction, including the energy scales associated with the three-body and left-hand cuts, is crucial to maintaining the correct analytic structure of the $ DD^* $ scattering amplitude near the threshold. Using $\chi$EFT up to next-to-leading order, we extract the low-energy $DD^*$ scattering amplitude from data at both physical and unphysical pion masses and predict the light-quark mass dependence of the $ T_{cc} $ pole position. All properties of the $ T_{cc} $ state inferred from the data strongly support its molecular nature.