标题： 重子谱的起源 显示英文标题

标题： Origins of the baryon spectrum

摘要： 我从轻子和奇异重子谱学的一个关键问题开始，这为理解基本动力学提供了一个线索。 接着我讨论了QCD中手征对称性的自发破缺，这意味着在低动量下必须存在准粒子——具有动态质量的组成夸克，这些准粒子应与其他准粒子——戈德斯通玻色子耦合。 因此，在低能区域，重子中的基本动力学很自然地归因于组成夸克之间的戈德斯通玻色子交换（GBE）。 以微观夸克-胶子自由度的原型——瞬子诱导的't Hooft相互作用为例，我说明了为什么GBE如此重要。 当't Hooft相互作用在qq t通道中迭代时，不可避免地会产生一个极点，对应于GBE。 这是一种典型的反屏蔽行为：在大动量下，相互作用由裸顶点表示，但在具有GBE量子数的通道中，它在小动量下会发散，从而解释了后者在低能区域的重要作用。 我展示了夸克之间显式依赖味的短程部分的GBE相互作用，可能与矢量介子交换相互作用相结合，如何解决重子谱学的一个关键问题，并展示了通过简单解析计算以及精确的半相对论三体方法得到的谱。 显示英文摘要

摘要： I begin with a key problem of light and strange baryon spectroscopy which suggests a clue for our understanding of underlying dynamics. Then I discuss spontaneous breaking of chiral symmetry in QCD, which implies that at low momenta there must be quasiparticles - constituent quarks with dynamical mass, which should be coupled to other quasiparticles - Goldstone bosons. Then it is natural to assume that in the low-energy regime the underlying dynamics in baryons is due to Goldstone boson exchange (GBE) between constituent quarks. Using as a prototype of the microscopical quark-gluon degrees of freedom the instanton-induced 't Hooft interaction I show why the GBE is so important. When the 't Hooft interaction is iterated in the qq t-channel it inevitably leads to a pole which corresponds to GBE. This is a typical antiscreening behavior: the interaction is represented by a bare vertex at large momenta, but it blows up at small momenta in the channel with GBE quantum numbers, explaining thus a distinguished role of the latter interaction in the low-energy regime. I show how the explicitly flavour-dependent short-range part of the GBE interaction between quarks, perhaps in combination with the vector-meson exchange interaction, solves a key problem of baryon spectroscopy and present spectra obtained in a simple analytical calculation as well as in exact semirelativistic three-body approach.