Mehen, T; Springer, RP, *Heavy-quark symmetry and the electromagnetic decays of excited charmed strange mesons*,
Physical Review D - Particles, Fields, Gravitation, and Cosmology, vol. 70 no. 7
(January, 2004),
pp. 074014-1-074014-12 [doi] .
**Abstract:**

*Heavy-hadron chiral perturbation theory ([Formula Presented]) is applied to the decays of the even-parity charmed strange mesons, [Formula Presented] and [Formula Presented]. Heavy-quark spin-symmetry predicts the branching fractions for the three electromagnetic decays of these states to the ground states [Formula Presented] and [Formula Presented] 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 [Formula Presented] Lagrangian can naturally account for this discrepancy. Finally the proposal that the [Formula Presented] ([Formula Presented] ) is a hadronic bound state of a [Formula Presented] 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. © 2004 The American Physical Society.*