Jido D, Hatsuda T, Kunihiro T
Department of Physics, Kyoto University, Kyoto, 606-8502, Japan.
Phys Rev Lett. 2000 Apr 10;84(15):3252-5. doi: 10.1103/PhysRevLett.84.3252.
Baryon resonances with even and odd parity are collectively investigated from the viewpoint of chiral symmetry (ChS). We propose a quartet scheme where Delta's and N(*)'s with even and odd parity form a chiral multiplet. This scheme gives parameter-free constraints on the baryon masses in the quartet, which are consistent with observed masses with spin 1 / 2,3 / 2,5 / 2. The scheme also gives selection rules in the one-pion decay: The absence of the parity nonchanging decay N(1720)-->piDelta(1232) is a typical example which should be confirmed experimentally to unravel the role of ChS in baryon resonances.
从手征对称性（ChS）的角度对具有偶宇称和奇宇称的重子共振态进行了综合研究。我们提出了一个四重态方案，其中具有偶宇称和奇宇称的Δ粒子和N*粒子形成一个手征多重态。该方案对四重态中的重子质量给出了无参数约束，这与自旋为1/2、3/2、5/2的观测质量一致。该方案还给出了单π介子衰变的选择规则：宇称不变衰变N(1720)→πΔ(1232)的不存在是一个典型例子，应通过实验加以证实，以揭示手征对称性在重子共振态中的作用。
