Doubly heavy tetraquark resonant states
Doubly heavy tetraquark resonant states
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DOI：
10.1016/j.physletb.2021.136800
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发表时间：
2021-06
影响因子：
4.4
通讯作者：
Qi Meng;M. Harada;E. Hiyama;A. Hosaka;M. Oka
中科院分区：
文献类型：
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作者：
Qi Meng;M. Harada;E. Hiyama;A. Hosaka;M. Oka
在组分夸克模型中研究了二重四夸克态B B q的能谱.用变分法求解了四体问题，其中利用真实的标度技术来确定高于衰变阈值的共振态。除了在先前的研究中报道的两个束缚态之外，我们还发现了几个高于B B束缚和B束缚B束缚阈值的窄共振态。它们的结构进行了研究，并解释了夸克动力学。发现一个自旋宇称J P= 1+的窄共振态是一个紧凑的四夸克态和一个B重B重散射态的混合态。这是由bb夸克之间强烈的色库仑吸引力驱动的。J P= 0−、1−和2−的负宇称激发共振在重夸克自旋对称下形成三重态。结果表明，由于重双夸克的强吸引关联，它们具有与单重重子的λ模相似的结构。
Spectrum of the doubly heavy tetraquarks, b b q¯ q¯, is studied in a constituent quark model. Four-body problem is solved in a variational method where the real scaling technique is used to identify resonant states above the fall-apart decay thresholds. In addition to the two bound states that were reported in the previous study we have found several narrow resonant states above the B B⁎ and B⁎ B⁎ thresholds. Their structures are studied and are interpreted by the quark dynamics. A narrow resonance with spin-parity J P= 1+ is found to be a mixed state of a compact tetraquark and a B⁎ B⁎ scattering state. This is driven by a strong color Coulombic attraction between the bb quarks. Negative-parity excited resonances with J P= 0−, 1− and 2− form a triplet under the heavy-quark spin symmetry. It turns out that they share a similar structure to the λ-mode of a singly heavy baryon as a result of the strongly attractive correlation for the doubly heavy diquark.