2016/04/25 by N. Matagne, Fl. Stancu · 1 citation
Physics and Astronomy · #hep-ph
paper · pdf · doi:10.1103/physrevd.93.096004
25 pages, to appear in Phys.Rev.D
arxiv created 2016/04/25 · arxiv updated 2016/05/25
The mass spectra of the [\bf 56, 2+] and [\bf 70, ℓ+] multiplets, both belonging to the N = 2 band, is reviewed in the 1/Nc expansion method. Previous studies, separately made for each multiplet, are presently updated to the 2014 Particle Data Group. The mass formula including corrections up to O(1/Nc) and first order in SU(3) flavor symmetry breaking, has the same independent operator basis in both cases. A special emphasis is made on the role of the SU(3) symmetry breaking operators Bi (i = 1,2,3). This can allow for multiplet assignment of Λ and Σ hyperons, which generally is quite difficult to make. Tentative assignments of hyperons with two- and one-star resonances are made to the [\bf 70, ℓ+] multiplet. Another important aim is to find out whether or not a common value of the coefficient c1 of the dominant operator in the mass formula, can well fit the present data in both multiplets. A negative answer, which is here the case, implies distinct Regge trajectories for symmetric and mixed symmetric states.