Full three-body treatment of the T⁺cc decay

Develop a full three-body Faddeev treatment of the decay T⁺cc → D⁰D⁰π⁺, including the sequential D*⁺ dynamics, to replace the effective two-body approximation used for the inelastic width.

Background

The paper models the dominant T⁺cc → D⁰D⁰π⁺ decay through the sequential process T⁺cc → D⁰D*⁺ followed by D*⁺ → D⁰π⁺. It compares a Breit–Wigner spectral treatment and an energy-dependent D*⁺ width with the simplified two-body approximation, finding essentially identical effective couplings because the D*⁺ is narrow.

Although the simplified treatment is considered adequate for the paper’s uncertainty analysis, a genuinely dynamical description of the three-body final state would require a Faddeev calculation. Such a calculation is left unresolved and would provide a more complete treatment of the decay dynamics beyond the effective two-body framework.

References

A full treatment would require the three-body Faddeev approach [8, 46], which we leave for future work.

— Near-Threshold Dynamics of \c{hi}c1(3872) and T+cc(3875) States via Effective Range Expansion and Monte Carlo Uncertainty Propagation  (2609.08289 - Likéné et al., 8 Sep 2026) in Appendix A, “T⁺cc → D⁰D⁰π⁺: D*⁺ Breit-Wigner Model”