Relativistic three-body scattering and the D0D*+−D+D*0 system

Abstract

Scattering amplitudes involving three-particle scattering processes are investigated within the isobar approximation which respects constraints from two- and three-body unitarity. The particular system considered is the D0D*+−D+D*0, where the D*+ (D*0) enters as a p-wave D+π0 or D0π+ (D0π0 or D+π−) resonance. The interaction potentials in the coupled-channel D0D*+−D+D*0 system contain the σ, ρ, ω, and π-exchange. The analytic continuation of the amplitudes across the three-body unitary cuts is investigated to search for poles on the unphysical Riemann sheets. Associated with an unstable particle D*+ (D*0) is a complex two-body unitarity cut, through which one can further analytically continue into another unphysical Riemann sheet. Dynamical singularities emerged from the π-exchange potential are stressed. The pole generated from the D0D*+−D+D*0 interaction and its line shape in D0D0π+ break-up production are in agreement with double-charmed tetraquark Tcc+ observed by the LHCb Collaboration. Published by the American Physical Society 2024