发表机构
Stony Brook University（石溪大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究二维QCD中\(N_c = 3\)时重子的Faddeev描述，通过精确耦合通道表示和变分求解，在手征极限等多种情况下研究重子谱等特性，在不同夸克质量条件下获得了多种重子相关结果。
AI 中文摘要
我们在\(N_c = 3\)的二维QCD中发展了一种光前Faddeev重子描述，其中精确的耦合通道表示将夸克 - 双夸克图像识别为单通道截断，并通过精确的矩阵元变分求解。在手征极限下，我们发现了一个完全无质量的最轻重子，与经典价解、离散光锥量子化（DLCQ）和玻色化一致；激发塔逐个状态地重现了韦伯的谱，并设定了价能隙\(1.371M^{\ast}_{\rm mes}\)。通道内容区分了这些状态：无质量重子是单通道的，有能隙的状态是真正的多通道的，并且所有重子雷杰轨迹都是介子类的。计算在耦合范围的两端都有依据：介子与重子的质量比与强耦合玻色化在\(0.3\%\) - \(4.3\%\)内一致，而价质量在弱耦合下将完整的离散光锥量子化（DLCQ）质量重现到\(0.04\%\)（介子）和\(0.15\%\)（重子）。扩展到两种简并味，我们发现无质量重子是\(\Delta\)类四重态，而在\(0.977M^{\ast}_{\rm mes}\)处类似\(N\)的二重态是好双夸克通道和坏双夸克通道的精确\(50\!:\!50\)叠加。添加一个重的奇异夸克，我们首次在价三夸克水平获得了\(QCD_2\)的超子谱：类似\(\Sigma\)的状态低于类似\(\Lambda\)的状态，颠倒了四维排序，手征阈值每个奇异夸克计两个K介子单位，并且盖尔曼 - 大久保关系在质量平方中得到保护。当所有三个夸克质量非简并时，类似质子的状态低于类似中子的状态，\(\Sigma^0\) - \(\Lambda\)混合出现，并且科尔曼 - 格拉肖关系在百分之几的水平成立。
英文摘要
We develop a light-front Faddeev description of baryons in two-dimensional QCD at $N_c=3$, in which an exact coupled-channel representation identifies the quark--diquark picture as a single-channel truncation, and solve it variationally with exact matrix elements. In the chiral limit we find an exactly massless lightest baryon, in agreement with the classic valence solutions, DLCQ, and bosonization; the excitation tower reproduces Webber's spectrum state by state and sets the valence gap $1.371\,M^{\ast}_{\rm mes}$. The channel content distinguishes these states: the massless baryon is single-channel, the gapped states are genuinely multi-channel, and all baryon Regge trajectories are of the meson class. The calculation is anchored at both ends of the coupling range: the meson-to-baryon mass ratio agrees with strong-coupling bosonization to $0.3$--$4.3\%$, while the valence masses reproduce the full discretized light cone quantization (DLCQ) masses to $0.04\%$ (meson) and $0.15\%$ (baryon) at weak coupling. Extending to two degenerate flavors, we find the massless baryon to be the $Δ$-like quartet, while the $N$-like doublet at $0.977\,M^{\ast}_{\rm mes}$ is an exact $50\!:\!50$ superposition of good- and bad-diquark channels. Adding a massive strange quark, we obtain, to our knowledge for the first time at the valence three-quark level, the hyperon spectroscopy of QCD$_2$: $Σ$-like states fall below $Λ$-like ones, inverting the four-dimensional ordering, the chiral thresholds count two kaon units per strange quark, and the Gell-Mann--Okubo relation is protected in mass squared. With all three quark masses non-degenerate, the proton-like state falls below the neutron-like one, $Σ^0$--$Λ$ mixing appears, and the Coleman--Glashow relation holds at the percent level.
Comments19 pages, 5 figures, 5 tables
