QCD sum rule analysis of excited Λ_c mass parameter

The mass parameter of orbitally excited $\Lambda_c$ baryons is calculated by using QCD sum rule in the framework of heavy quark effective theory. Two kinds of interpolating current for the excited heavy baryons are introduced. It is obtained that $\bar{\Lambda}=1.08^{+0.095}_{-0.104}$ GeV for the non-derivative current and $\bar{\Lambda}=1.06^{+0.090}_{-0.107}$ GeV for the current with derivative. These results are consistent with experimental data.