Progress in Particle and Nuclear Physics ( IF 9.6 ) Pub Date : 2021-05-03 , DOI: 10.1016/j.ppnp.2021.103868 Tetsuo Hyodo , Masayuki Niiyama
The strange quark plays a unique role in QCD, reflecting its intermediate mass between the light and heavy quarks. In recent years, remarkable progress has been made in the spectroscopy of baryons with strangeness. Many new features of the strange baryon spectrum have been revealed by accurate experimental data with novel techniques, as well as systematic developments of theoretical framework to describe hadron resonances. The basic properties of strange baryons, namely, the pole positions, spin and parity, and decay branching ratios, are being determined accurately. As a consequence, the Particle Data Group has added new entries in the particle listings, such as the and the . The developments of the spectroscopy stimulate intensive discussion on the exotic internal structure of strange baryons beyond the ordinary three-quark configuration. In this review, we introduce the basics of QCD, the scattering theory, and the exotic internal structure of hadrons, emphasizing the importance of the pole positions of the scattering amplitude for the characterization of hadron resonances. We then summarize the current status of selected strange baryon resonances; , , , , and , from theoretical and experimental viewpoints.
中文翻译:
QCD 和奇怪的重子谱
奇夸克在 QCD 中扮演着独特的角色,反映了它介于轻夸克和重夸克之间的中间质量。近年来,奇异重子的光谱研究取得了显着进展。使用新技术的准确实验数据以及描述强子共振的理论框架的系统发展揭示了奇异重子谱的许多新特征。奇异重子的基本特性,即极位、自旋和奇偶性以及衰变分支比,正在被准确地确定。因此,粒子数据组在粒子列表中添加了新条目,例如 和 . 光谱学的发展激发了对超越普通三夸克构型的奇异重子内部结构的深入讨论。在这篇综述中,我们介绍了 QCD 的基础知识、散射理论和强子的奇异内部结构,强调了散射幅度的极点位置对于表征强子共振的重要性。然后我们总结了选定的奇怪重子共振的现状;, , , , 和 ,从理论和实验的角度来看。