Global analysis of the negative parity nonstrange baryons in the 1/Nc expansion

Abstract

A global study of the negative parity nonstrange baryon observables is performed in the framework of the 1/Nc expansion. Masses, partial decay widths and photo couplings are simultaneously analyzed. A main objective is to determine the composition of the spin ½ and 3/2 nucleon states, which come in pairs and involve two mixing angles which can be determined and tested for consistency by the mentioned observables. The issue of the assignment of those nucleon states to the broken SU(4)×O(3) mixed-symmetry multiplet is studied in detail, with the conclusion that the assignment made in the old studies based on the nonrelativistic quark model is the preferred one. In addition, the analysis involves an update of the input data with respect to previous works.