The older of 1P and 2S states of baryons in the chiral quark model

The well-known order reverse problem of 1P and 2S states of baryons in naive quark model is investigated in the chiral quark model. By incorporating the Goldstone boson exchange, we found that the mass of 2S state is always lower than 1P state for the three-quark baryons in the high precision calculation of three-body system. The Roper resonance $N^*(1440)$ can be explained as the first radial excitation state of nucleon. The calculation is also extended to the heavy quark sector, among the newly discovered five excited states of $\Omega^0_c$, two states maybe the 2S states of ssc system and the $\Xi_{cc}(3621)$ could be the ground state of ucc with IJP is $1/2 3/2^+$.