论文标题
组成夸克模型中双重融合的tetraquark $ t_ {cc}^+$的性质
Nature of the doubly-charmed tetraquark $T_{cc}^+$ in a constituent quark model
论文作者
论文摘要
最近发现的$ t_ {cc}^+$被评估为$ j^p = 1^+$ sector中的$ dd^*$分子结构。 A coupled-channels calculation in charged basis, considering the $D^0D^{*\,+}$, $D^+D^{*\,0}$ and $D^{*\,0}D^{*\,+}$ channels, is done in the framework of a constituent quark model that successfully described other molecular candidates in the charmonium spectrum such as the $ x（3872）$。 $ t_ {cc}^+$作为$ d^0d^{*\，+} $分子（$ 87 \％$），具有$ 387 $ kev/c $^2 $的绑定能量，与实验测量协议达成协议。国家的夸克含量迫使包含交换图，以处理$ d $介子之间无法区分的夸克，这被认为是结合分子必不可少的。还分析了分子的$ d^0d^0π^+$线形状，散射长度和有效范围，发现与LHCB分析一致。我们在其他魅力和底部搜索$ t_ {cc}^+$的其他合作伙伴中寻找不同的候选人。特别是，在魅力部门，我们找到一个浅$ j^p = 1^+$ $ $ d^+d^{*\，0} $ molecule（$ 83 \％$），称为$ t_ {cc}^\ prime $，仅$ 1.8 $ 1.8 $ 1.8 $ mev $ 1.8 $ mev;在底部扇区中，我们找到一个等轴和一个等异分型$ j^p = 1^+$底部合作伙伴，如$ bb^*$分子，分子$ 21.9 $ meV/c $^2 $（$ i = 0 $）和$ 10.5 $ mev/c $^2 $（$^2 $（$ i = 1 $），分别为$ b^0b^0b^0b^0b^$}
The recently discovered $T_{cc}^+$ is evaluated as a $DD^*$ molecular structure in the $J^P=1^+$ sector. A coupled-channels calculation in charged basis, considering the $D^0D^{*\,+}$, $D^+D^{*\,0}$ and $D^{*\,0}D^{*\,+}$ channels, is done in the framework of a constituent quark model that successfully described other molecular candidates in the charmonium spectrum such as the $X(3872)$. The $T_{cc}^+$ is found as a $D^0D^{*\,+}$ molecule ($87\%$) with a binding energy of $387$ keV/c$^2$ and a width of $81$ keV, in agreement with the experimental measurements. The quark content of the state forces the inclusion of exchange diagrams to treat indistinguishable quarks between the $D$ mesons, which are found to be essential to bind the molecule. The $D^0D^0π^+$ line shape, scattering lengths and effective ranges of the molecule are also analyzed, which are found to be in agreement with the LHCb analysis. We search for further partners of the $T_{cc}^+$ in other charm and bottom sectors, finding different candidates. In particular, in the charm sector we find a shallow $J^P=1^+$ $D^+D^{*\,0}$ molecule ($83\%$), dubbed $T_{cc}^\prime$, just $1.8$ MeV above the $T_{cc}^+$ state. In the bottom sector, we find an isoscalar and an isovector $J^P=1^+$ bottom partners, as $BB^*$ molecules lying $21.9$ MeV/c$^2$ ($I=0$) and $10.5$ MeV/c$^2$ ($I=1$), respectively, below the $B^0B^{*\,+}$ threshold.
