Abstract :
In the heavy quark limit, there are three independent strong axial coupling constants in chiral Lagrangians for ground-state heavy hadrons: g in the meson sector, and g1, g2 in the baryon sector. The coupling g2 is extracted from recent CLEO measurements of Σc∗ → Λcπ to be ∥g2∥ = 0.57 ± 0.10, in agreement with the nonrelativistic quark model expectation but in 2σ deviation from the large-Nc argument. The parameter g1 cannot be determined directly from strong decays of heavy baryons. Nevertheless, some information of g1 can be learned from the radiative decay Ξ′c∗0 → Ξc0γ, which is prohibited at tree level by SU(3) symmetry but induced by chiral loops. A measurement of Γ(Ξ′c∗0 → Ξc0γ) will yield two possible solutions for g1. Assuming the validity of the quark model relations among different coupling constants, the experimental value of g2 implies that ∥g∥ = 0.70 ± 0.12 and ∥g1∥ = 0.93 ± 0.16.
