标题： 可能的 J^P=0^-,T=0 双核子的组成夸克模型计算 显示英文标题

标题： Constituent Quark Model Calculation for a possible J^P=0^-,T=0 Dibaryon

摘要： 存在实验证据表明，具有量子数 J^P=0^-,T=0 和质量 2065 MeV 的双核子共振 d' 可能是原子核上 (\pi ^+ ,\pi ^- ) 双电荷交换截面中窄峰的来源。 我们在成分夸克模型中研究具有这些量子数的六夸克系统，包括线性禁闭、短程有效一胶子交换以及夸克之间的手征相互作用（\pi 和 \sigma 交换）。 我们使用不同的约化链对所有可能的 J^P=0^-,T=0 六夸克态以及具有 N=1 和 N=3 振动谐波激发态进行分类。 在包含唯一 N=1 态和来自 N=3 壳层的 10 个最重要态的基组中对六夸克哈密顿量进行对角化。 我们发现，对于大多数可能的参数集，这种“双核子”的质量高于 N(939)+N^\ast (1535) 阈值。 在目前的背景下描述假设的 d'(2065) 的唯一可能性是将禁闭强度降低到非常小的值，但代价是无法描述负宇称共振 N^\ast 。 我们还分析了 J^P=0^-,T=2,N=1 六夸克态。 显示英文摘要

摘要： There exists experimental evidence that a dibaryon resonance d' with quantum numbers J^P=0^-,T=0 and mass 2065 MeV could be the origin of the narrow peak in the (\pi^+ ,\pi^- ) double charge exchange cross--sections on nuclei. We investigate the six--quark system with these quantum--numbers within the constituent quark model, with linear confinement, effective one--gluon exchange at short range and chiral interactions between quarks (\pi and \sigma exchange). We classify all possible six quark states with J^P=0^-,T=0, and with N=1 and N=3 harmonic oscillator excitations, using different reduction chains. The six--quark Hamiltonian is diagonalized in the basis including the unique N=1 state and the 10 most important states from the N=3 shell. We find, that with most of the possible sets of parameters, the mass of such a "dibaryon" lies above the N(939)+N^\ast(1535) threshold. The only possibility to describe the supposed d'(2065) in the present context is to reduce the confinement strength to very small values, however at the expense of describing the negative parity resonances N^\ast. We also analyze the J^P=0^-,T=2,N=1 six--quark state.