发表机构
Tianjin University of Technology; Henan University; University of the Punjab; Zhengzhou University（天津工业大学; 河南大学; 旁遮普大学; 郑州大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
基于LHCb新发现的窄底奇异介子，用精细组分夸克模型结合耦合道动力学，解释了其近阈值分子结构和异常窄宽度，并预测了1+伙伴态作为关键检验。
AI 中文摘要
最近，LHCb 合作组在 $B_s^0\pi^0$ 不变质量谱中报告了一个新的窄底奇异介子 $B_{s0}^*(5700)$，其质量为 $M= (5698.9 \pm 1.5 \pm 0.6)$~MeV，宽度 $\Gamma<9.8$~MeV，自旋-宇称 $J^P=0^+$。受此观测启发，我们在一个两阶段精细组分夸克模型中研究了低激发 $P$-波 $B_s$ 介子。禁闭-单胶子交换势（$\alpha_s^2$）的单圈辐射修正使整个多重态降低 $25$--$50$~MeV，并改善了能级次序；然而，在纯致密图像中，标量 $B_{s0}^*$ 的质量仍比 LHCb 数据高约 $120$~MeV。耦合道动力学的引入是决定性的：$BK$ 阈值靠近标量质量，产生了一个可观的介子-介子（类分子）分量，将极点拉低至约 $5727$~MeV，与测量值相差在 $30$~MeV 以内，同时抑制了 $S$-波相空间，自然地解释了异常窄的宽度。对于 $1^+$ $B_{s1}$ 伙伴态，我们得到了一致的结果，预测其质量约为 $\sim5747$--$5755$~MeV，与手征双重态方案一致。$B_{s1}$ 态预计非常窄，主要通过同位旋破坏的 $B_s^*\pi^0$ 和辐射衰变 $B_s\gamma$、$B_s^*\gamma$ 模式衰变，为 LHC Run~3 提供了清晰的发现目标。$j_\ell=1/2$ 态的 $E1$ 辐射宽度预测在 $50\sim 60$~keV 范围内，纯 $j_\ell=3/2$ 态 $B_{s2}^*(5840)$ 的强宽度（$1.5$~MeV）重现了测量值。我们的结果支持将 $B_{s0}^*(5700)$ 解释为具有强分子修饰的近阈值标量态，并将预测的 $1^+$ $B_{s1}(5747)$ 确立为检验 $B_s$ 扇区强子动力学的决定性测试。
英文摘要
Recently, the LHCb Collaboration reported a new narrow bottom-strange meson, $B_{s0}^*(5700)$ with mass $M= (5698.9 \pm 1.5 \pm 0.6)$~MeV, width $Γ<9.8$~MeV, and spin-parity $J^P=0^+$ in the $B_s^0π^0$ invariant-mass spectrum. Motivated by this observation, we study the low-lying $P$-wave $B_s$ mesons in a two-stage refined constituent quark model. The one-loop radiative corrections to the confinement--one-gluon exchange potential ($α_s^2$) lower the whole multiplet by $25$--$50$~MeV and improve the level ordering; however, the scalar $B_{s0}^*$ mass still exceeds the LHCb data by $\sim120$~MeV in a purely compact picture. The inclusion of the coupled-channel dynamics is decisive: the $BK$ threshold, lying close to the scalar mass, generates a sizeable meson--meson (molecular-like) component that pulls the pole down to $\sim5727$~MeV, within $30$~MeV of the measurement, and simultaneously suppresses the $S$-wave phase space, naturally accounting for the anomalously narrow width. Consistent results are obtained for the $1^+$ $B_{s1}$ partner, for which we predict a mass $\sim5747$--$5755$~MeV, in agreement with the chiral-doubling scenario. The $B_{s1}$ state is expected to be very narrow and decaying mainly through the isospin-violating $B_s^*π^0$ and radiative $B_sγ$, $B_s^*γ$ modes, providing a clear discovery target at LHC Run~3. The $E1$ radiative widths of the $j_\ell=1/2$ states are predicted at the $50\sim 60$~keV, and the strong width of the pure $j_\ell=3/2$ state $B_{s2}^*(5840)$ ($1.5$~MeV) reproduces the measurement. Our results support the interpretation of $B_{s0}^*(5700)$ as a near-threshold scalar with strong molecular dressing and establish the predicted $1^+$ $B_{s1}(5747)$ as the decisive test of the hadronic dynamics in the $B_s$ sector.
Comments14 pages
