Heavy-quark symmetry and the electromagnetic decays of excited charmed strange mesons

Heavy-hadron chiral perturbation theory (HHχPT) is applied to the decays of the even-parity charmed strange mesons, Ds0(2317) and Ds1(2460). Heavy-quark spin-symmetry predicts the branching fractions for the three electromagnetic decays of these states to the ground states Ds and Ds* in terms of a single parameter. The resulting predictions for two of the branching fractions are significantly higher than current upper limits from the CLEO experiment. Leading corrections to the branching ratios from chiral loop diagrams and spin-symmetry violating operators in the HHχPT Lagrangian can naturally account for this discrepancy. Finally the proposal that the Ds0(2317) (D s1(2460)) is a hadronic bound state of a D(D*) meson and a kaon is considered. Leading order predictions for electromagnetic branching ratios in this molecular scenario are in very poor agreement with existing data.

Duke Scholars

Author Thomas C. Mehen Physics

Author Roxanne P. Springer Physics