The mass splittings of the baryons belonging to the $[{ \bf 70},1^-]$-plet are derived by using a simple group theoretical approach to the matrix elements of the mass formula. The basic conclusion is that the first order correction to the baryon masses is of order $1/N_c$ instead of order $N^0_c$, as previously found. The conceptual difference between the ground state and the excited states is therefore removed.
Categories: hep-ph
![The $[{\bf 70},1^-]$ baryon multiplet in the $1/N_c$ expansion revisited](http://n.sinaimg.cn/news/transform/w600h400/20180309/SU1c-fxpwyhw3367454.jpg?zdy)





