标题： 奇异数$S = -3$和$-4$强子-强子相互作用的相对论手征有效场理论研究 显示英文标题

标题： Strangeness $S = -3$ and $-4$ baryon-baryon interactions in relativistic chiral effective field theory

摘要： 奇异性$S=-3$和$-4$的重子-重子相互作用在相对论性手征有效场论的领头阶被研究。 首先，从$S=-1$部分推导出势，假设相应的低能常数通过SU(3)味对称性相互关联。 然而，与最先进的格点QCD模拟比较表明，SU(3)味对称性破缺效应不能被忽略。 为了考虑这些效应，我们分别拟合$\Xi\Sigma$和$\Xi\Xi$通道的格点QCD数据，重新确定了两组低能常数。 拟合结果表明，格点QCD两个通道的$S$波相移可以相当好地描述。 在没有任何额外的自由低能常数的情况下，对于${}^3D_1$通道预测的相移和混合角$\varepsilon_1$也与$S=-3$通道的格点QCD数据在定性上一致，而$S=-4$通道的结果仍需未来格点QCD模拟的验证。利用所得到的低能常数，在物理点处计算了这两个通道的$S$波散射长度和有效范围。 最后，结合我们在之前工作中得到的$S=0$和$-2$结果，我们研究了在重子-重子相互作用中不可约表示$27$随 strangeness（奇异数）增加而演变的情况。 结果表明，随着奇异数从$S=0$增加到$S=-2$，吸引力急剧下降，但随后直到$S=-4$一直保持相对稳定。 结果表明，在$\Xi\Sigma$和$\Xi\Xi$通道中存在束缚态的可能性相当小。 显示英文摘要

摘要： The strangeness $S=-3$ and $-4$ baryon-baryon interactions are investigated in the relativistic chiral effective field theory at leading order. First, the potentials are derived from the $S=-1$ sector assuming that the corresponding low-energy constants are related to each other via SU(3) flavor symmetry. The comparison with the state-of-the-art lattice QCD simulations, show, however, that SU(3) flavor symmetry breaking effects can not be neglected. In order to take into account these effects, we redetermine two sets of low-energy constants by fitting to the lattice QCD data in the $\Xi\Sigma$ and $\Xi\Xi$ channels respectively. The fitting results demonstrate that the lattice QCD $S$-waves phase shifts for both channels can be described rather well. Without any additional free low-energy constants, the predicted phase shifts for the ${}^3D_1$ channel and the mixing angle $\varepsilon_1$ are also in qualitative agreement with the lattice QCD data for the $S=-3$ channel, while the results for the $S=-4$ channel remain to be checked by future lattice QCD simulations. With the so-obtained low-energy constants, the $S$-wave scattering lengths and effective ranges are calculated for these two channels at the physical point. Finally, in combination with the $S=0$ and $-2$ results obtained in our previous works, we study the evolution of the irreducible representation $27$ in the baryon-baryon interactions as a function of increasing strangeness. It is shown that the attraction decreases dramatically as strangeness increases from $S=0$ to $S=-2$, but then remains relatively stable until $S=-4$. The results indicate that the existence of bound states in the $\Xi\Sigma$ and $\Xi\Xi$ channels is rather unlikely.