Mixing angles between the tetraquark states with two heavy quarks within QCDsum rules

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Turkish Journal of Physics, vol.45, no.6, pp.390-399, 2021 (ESCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 45 Issue: 6
  • Publication Date: 2021
  • Doi Number: 10.55730/1300-0101.1003
  • Journal Name: Turkish Journal of Physics
  • Journal Indexes: Emerging Sources Citation Index (ESCI), Scopus, Academic Search Premier, Compendex, INSPEC, TR DİZİN (ULAKBİM)
  • Page Numbers: pp.390-399
  • Keywords: Mixing angles, tetraquark states, QCD sum rules, MAGNETIC-MOMENTS, MESONS
  • Middle East Technical University Affiliated: Yes


© 2021 TÜBITAK.LHCb collaboration has recently announced the observation of a doubly charmed tetraquark T+ccūd¯ state with spin parity JP = 1+. This exotic state can be explained as a molecular state with small binding energy. According to conventional quark model, both D+D0∗ and (D0D+∗) 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 Tcc states are calculated. Moreover, the analyses 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.