Two-pion decay widths of excited charm mesons Original Research Article

The widths for ππ decay of the L=1 charm mesons are calculated by describing the pion coupling to light constituents quarks by the lowest-order chiral interaction. The wavefunctions of the charm mesons are obtained as solutions to the covariant Blankenbecler–Sugar equation. These solutions correspond to an interaction Hamiltonian modeled as the sum of a linear scalar confining and a screened one-gluon exchange (OGE) interaction. This interaction induces a two-quark contribution to the amplitude for two-pion decay, which is found to interfere destructively with the single-quark amplitude. For the currently known L=1 D mesons, the total ππ-decay widths are found to be ∼1 MeV for the DView the MathML source and ∼3 MeV for the DView the MathML source if the axial coupling of the constituent quark is taken to be View the MathML source. The as yet undiscovered spin-singlet DView the MathML source state is predicted to have a larger width of 7–10 MeV for ππ decay.