Schat C L, Goity J L, Scoccola N N
Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.
Phys Rev Lett. 2002 Mar 11;88(10):102002. doi: 10.1103/PhysRevLett.88.102002. Epub 2002 Feb 25.
The masses of the negative parity 70-plet baryons are analyzed in large N(c) QCD to order 1/N(c) and to first order in SU(3) symmetry breaking. The existing experimental data are well reproduced and 20 new observables are predicted. The leading order SU(6) spin-flavor symmetry breaking is small and, as it occurs in the quark model, the subleading in 1/N(c) hyperfine interaction is the dominant source of the breaking. It is found that the Lambda(1405) and Lambda(1520) are well described as three-quark states and spin-orbit partners. New relations between splittings in different SU(3) multiplets are found.
在大N(c) QCD中对负宇称70重态重子的质量进行了分析，精确到1/N(c)阶以及SU(3)对称性破缺的一阶。现有实验数据得到了很好的重现，并预测了20个新的可观测量。主导阶的SU(6)自旋-味对称性破缺很小，并且如同在夸克模型中那样，1/N(c)超精细相互作用中的次主导项是破缺的主要来源。结果发现，Λ(1405)和Λ(1520)可以很好地描述为三夸克态和自旋-轨道伙伴。还发现了不同SU(3)多重态中分裂之间的新关系。
