We have investigated the electromagnetic decays of the antitriplet and sextet charmed baryon systems with $J^P={\frac{1}{2}}^{+},{\frac{3}{2}}^{+}$ in the framework of the heavy baryon chiral perturbation theory. We first construct the chiral Lagrangians at $O(p^2)$ and $O(p^3)$. Then we calculate the electromagnetic (EM) decay amplitudes of the charmed baryon systems up to $O(p^3)$. With the help of the quark model, we estimate the low energy constants. The numerical results of the EM decay widths show good convergence of the chiral expansion. We notice that the two neutral EM decay processes ${\mathrm{\Xi }}_c^{\prime 0}\to \gamma +{\mathrm{\Xi }}_c^0$ and ${\mathrm{\Xi }}_c^{*0}\to \gamma +{\mathrm{\Xi }}_c^0$ are strongly suppressed by the SU(3) U-spin flavor symmetry. With the same formalism, we also estimate the EM decay widths of the bottomed baryons. The EM decay widths of the heavy baryons may be measured at facilities such as LHCb and JPARC. The explicit chiral structures of the heavy baryon decay amplitudes derived in this work may be useful to the possible chiral extrapolations of the future lattice simulations of these EM decay amplitudes.

• Received 14 May 2015

DOI:https://doi.org/10.1103/PhysRevD.92.054017