Crede Volker, Yelton John
Department of Physics, Florida State University, Tallahassee, FL 32306, United States of America.
Department of Physics, University of Florida, Gainesville, FL 32611, United States of America.
Rep Prog Phys. 2024 Sep 30;87(10). doi: 10.1088/1361-6633/ad7610.
The first hyperon was discovered about 70 years ago, but the nature of these particles, particularly with regard to multistrange hyperons, and many of their properties can still be considered to be literally strange. A dedicated and successful global spectroscopy program in the 1960s and 1970s usingK-beams revealed many multistrange candidates, but the available evidence of their existence is statistically limited. For this reason, there is still much to learn about the systematics of the spectrum of excited hyperon states and what they have in common with their non-strange companions, or how they differ from the nucleon and Δ resonances. Results from photo- and electroproduction experiments off the proton and neutron using polarized beams and targets have provided intriguing evidence for new nucleon excitations and shed light on the structure of some of the known nucleon and Δ states. Recent years have also seen a great deal of progress in the field of charmed and bottom baryon spectroscopy. Unprecedented data from the Large Hadron Collider in particular indicate continued rapid progress in the field of bottom baryons. On the theoretical side, baryons with one heavy quarkand a lightsystem serve as an ideal laboratory for studying light(diquark) correlations and the dynamics of the light quarks in the colour environment of a heavy quark. In this review, we discuss the status of doubly and triply strange Ξ as well as Ω baryons, and the properties of all the known charmed and bottom states. The comparison of the two heavy sectors reveals many similarities as predicted by heavy-quark symmetries, together with differences in mass splittings easily understood by potential models. The multi-strange hyperons bridge the under-explored gap between the light- and the heavy-flavour baryons. How do the properties of a singly charmed-system change with decreasing mass of the heavy quark in the transition to a doubly strange-system with a heavier quark-quark system relative to one light quark? Significant progress towards understanding hyperon resonances is expected in coming years from the ongoing experiments at the high-energy collider facilities and planned experiments usingbeams at Jefferson Laboratory and J-PARC.
首个超子大约在70年前被发现，但这些粒子的性质，尤其是多奇异超子的性质，以及它们的许多特性在字面上仍可被认为是奇特的。20世纪60年代和70年代利用K介子束开展的一项专门且成功的全球光谱学计划揭示了许多多奇异候选粒子，但其存在的现有证据在统计上是有限的。因此，关于激发超子态光谱的系统学以及它们与非奇异伙伴的共同之处，或者它们与核子和Δ共振的差异，仍有很多有待了解。使用极化束和靶对质子和中子进行的光生和电生实验结果为新的核子激发提供了引人入胜的证据，并揭示了一些已知核子和Δ态的结构。近年来，粲重子和底重子光谱学领域也取得了很大进展。特别是大型强子对撞机提供的前所未有的数据表明底重子领域持续快速发展。在理论方面，含有一个重夸克和一个轻夸克系统的重子是研究轻（双夸克）关联以及重夸克色环境中轻夸克动力学的理想实验室。在这篇综述中，我们讨论了双重和三重奇异的Ξ以及Ω重子的现状，以及所有已知粲重子和底重子态的特性。对两个重夸克领域的比较揭示了重夸克对称性所预测的许多相似之处，以及通过势模型很容易理解的质量分裂差异。多奇异超子填补了轻味和重味重子之间探索不足的空白。在向具有比一个轻夸克更重的夸克 - 夸克系统的双重奇异系统转变过程中，单粲重子系统的性质如何随着重夸克质量的降低而变化？预计未来几年，高能对撞机设施正在进行的实验以及计划在杰斐逊实验室和日本质子加速器研究中心使用束流进行的实验将在理解超子共振方面取得重大进展。
