双重重子中的同位旋与味SU(3)对称性破缺
Isospin and flavor SU(3) symmetry breaking in doubly heavy baryons
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中文总结 AI 辅助
基于π介子平均场方法，利用轻和单重重子数据确定参数，预言双粲重子三重态质量劈裂，其中同位旋劈裂与LHCb观测一致，并给出自旋3/2态和双底谱。
中文摘要 AI 辅助
LHCb合作组最近对$\Xi_{cc}^{+}$和$\Omega_{cc}^{+}$的观测完善了双粲重子的基态三重态，因此其内部质量模式可用于检验轻夸克扇区中的对称性破缺。我们在π介子平均场方法框架内研究双重重子，将其视为$N_c-2$个价轻夸克在紧凑重双夸克存在下产生π介子平均场时的束缚态。味SU(3)和同位旋对称性破缺的所有动力学参数均由轻和单重重子扇区确定，超精细耦合由单重重子谱固定。采用PDG值给出的重夸克质量，仅用测得的$\Xi_{cc}^{++}$质量来确定轻子系统的集体转动能量，因此三重态内的质量劈裂是预言。我们得到$M_{\Xi_{cc}^{+}}=(3620.17\pm13.08)$ MeV和$M_{\Omega_{cc}^{+}}=(3746.62\pm13.22)$ MeV。预言的同位旋劈裂$M_{\Xi_{cc}^{++}}-M_{\Xi_{cc}^{+}}=(1.43\pm0.38)$ MeV与LHCb对$\Xi_{cc}^{+}$的观测一致。我们还给出了自旋3/2双粲态和双底重子谱的质量。
英文摘要
The recent observations of the $Ξ_{cc}^{+}$ and the $Ω_{cc}^{+}$ by the LHCb Collaboration complete the ground-state triplet of doubly charmed baryons, so that its internal mass pattern can be used to test symmetry breaking in the light-quark sector. We study the doubly heavy baryons within the pion mean-field approach, regarding them as bound states of the $N_c-2$ valence light quarks that generate the pion mean field in the presence of a compact heavy diquark. All dynamical parameters for flavor SU(3) and isospin symmetry breaking were determined in the light and singly heavy baryon sectors, and the hyperfine coupling is fixed by the singly heavy spectrum. With the heavy-quark masses taken from the PDG values, the measured $Ξ_{cc}^{++}$ mass is used only to determine the collective rotational energy of the light subsystem, so that the mass splittings within the triplet are predictions. We obtain $M_{Ξ_{cc}^{+}}=(3620.17\pm13.08)$ MeV and $M_{Ω_{cc}^{+}}=(3746.62\pm13.22)$ MeV. The predicted isospin splitting, $M_{Ξ_{cc}^{++}}-M_{Ξ_{cc}^{+}}=(1.43\pm0.38)$ MeV, is consistent with the LHCb observation of the $Ξ_{cc}^{+}$. We also present the masses of the spin-3/2 doubly charmed states and the doubly bottom spectrum.
发表机构
- Hoseo University（湖西大学）
- Inha University（仁荷大学）
- Korea Institute for Advanced Study (KIAS)（韩国高等研究院）
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