P-wave charmed baryons from QCD sum rules
Abstract
We study the P-wave charmed baryons using the method of QCD sum rule in the framework of heavy quark effective theory (HQET). We consider systematically all possible baryon currents with a derivative for internal rho- and lambda-mode excitations. We have found a good working window for the currents corresponding to the rho-mode excitations for Lambdac(2595), Lambdac(2625), Xic(2790) and Xic(2815) which complete two SU(3) 3Fbar multiplets of J(P)=1/2(-) and 3/2(-), while the currents corresponding to the lambda-mode excitations seem also consistent with the data. Our results also suggest that there are two Sigmac(2800) states of J(P)=1/2(-) and 3/2(-) whose mass splitting is 14 7 MeV, and two Xic(2980) states whose mass splitting is 12 7 MeV. They have two Omegac partners of J(P) = 1/2(-) and 3/2(-), whose masses are around 3.25 0.20 GeV with mass splitting 10 6 MeV. All of them together complete two SU(3) 6F multiplets of J(P)=1/2(-) and 3/2(-). They may also have J(P)=5/2(-) partners. Xic(3080) may be one of them, and the other two are Sigmac(5/2(-)) and Omegac(5/2(-)), whose masses are 85 23 and 50 27 MeV larger.