Strong and electromagnetic decays of p-wave heavy baryons $Λ_{c1}, Λ^*_{c1}$

Abstract

We first calculate the binding energy, the pionic and electromagnetic couping constants of the lowest lying p-wave heavy baryon doublet $Λ_{c1}$, $Λ_{c1}^*$ in the leading order of the heavy quark expansion. Then we calculate the two-body decay widths with these couplings and compare our results with other approaches. Our results are $Γ(Λ_{c1}\to Σ_c π, Σ_c γ, Σ^*_c γ) =2.7, 0.011, 0.001$ MeV and $Γ(Λ^*_{c1}\to Σ_c π, Σ_c γ, Σ^*_c γ, Λ_{c1} γ) =33, 5, 6, 0.014$ keV respectively. We find $Λ_{c1}, Λ^*_{c1}\to Λ_c γ$ is strictly forbidden in the leading order of the heavy quark expansion. At the order of ${\cal O} (1/m_c)$ their widths are $36, 48$ keV respectively.