论文标题
在QCD总规则中将Tetraquark状态之间的角度与两个重夸克之间的混合角度混合
Mixing angles between the tetraquark states with two heavy quarks within QCD sum rules
论文作者
论文摘要
LHCB合作最近宣布观察一个双重迷人的Tetraquark $ t_ {cc \ bar {u} \ bar {d}}}^+$ state with spin parity $ j^p = 1^+$。这种外来状态可以解释为具有小结合能的分子状态。根据常规夸克模型，$ d^+ d^{0 \ ast} $和$（d^0 d^{+ ast}）$多quark状态的质量和风味在确切的$ su（3）$对称性中具有相同的质量和风味。但是，由于夸克质量不同，因此违反了$ su（3）（SU（2））$对称性，因此，质量和风味特征态不一致。质量特征状态可以表示为风味本征的线性组合，其特征在于混合角$θ$。在目前的工作中，计算$ t_ {cc} $状态之间的可能的混合角度。此外，尽管尚未观察到这些状态，但对所有可能的四夸克场景进行了分析。我们对双重诱人的Tetraquark国家之间混合角度的预测表明，$ SU（3）$对称破坏约为$ 7 \％$ $。
LHCb Collaboration has recently announced the observation of a doubly charmed tetraquark $T_{cc \bar{u} \bar{d}}^+$ state with spin parity $J^P = 1^+$. This exotic state can be explained as a molecular state with small binding energy. According to conventional quark model, both $D^+ D^{0\ast}$ and $(D^0 D^{+\ast})$ multiquark states are expected to have the same mass and flavor in the exact $SU(3)$ symmetry. However, since the quark masses are different, $SU(3) (SU(2))$ symmetry is violated, hence, the mass and flavor eigenstates do not coincide. The mass eigenstates can be represented as a linear combination of the flavor eigenstates, which is characterized by the mixing angle $θ$. In the present work, the possible mixing angles between the $T_{cc}$ states are calculated. Moreover, the analysis are extended for all the possible tetraquarks scenarios with two heavy and two light quarks within the molecular picture although those states have not been observed yet. Our prediction on mixing angle between doubly charmed tetraquark states shows that $SU(3)$ symmetry breaking is around $7\%$ maximally.
