Strong decays of T cc plus at NLO in an effective field theory

The T+cc exotic meson, discovered by the LHCb Collaboration in 2021, can be interpreted as a molecular state of D(*)0 and D(*)+ mesons. We compute next-to-leading-order (NLO) contributions to the strong decay of T+cc in an effective field theory for D mesons and pions, considering contributions from one-pion exchange and final-state rescattering. Corrections to the total width, as well as the differential distribution in the invariant mass of the final-state D-meson pair are computed. The results remain in good agreement with LHCb experimental results when the NLO contributions are added. The leading uncertainties in the calculation come from terms which depend on the scattering length and effective range in D-meson scattering.

Automated summary

The T+cc exotic meson, discovered by the LHCb Collaboration in 2021, is likely a molecular state composed of D(*)0 and D(*)+ mesons. In this study, we calculate the next-to-leading-order (NLO) contributions to the strong decay of T+cc using an effective field theory for D mesons and pions, considering the effects of one-pion exchange and final-state rescattering. Our results, which include corrections to the total width and differential distribution in the invariant mass of the final-state D-meson pair, are consistent with experimental data from LHCb when NLO contributions are taken into account. We identify the primary uncertainties in our calculations as being related to the scattering length and effective range in D-meson scattering.