Mass spectrum and strong decays of tetraquark $${\bar{c}}{\bar{s}} qq$$ states

Abstract

We systematically study the mass spectrum and strong decays of the S-wave $${\bar{c}}{\bar{s}} q q$$ c ¯ s ¯ q q states in the compact tetraquark scenario with the quark model. The key ingredients of the model are the Coulomb, the linear confinement, and the hyperfine interactions. The hyperfine potential leads to the mixing between different color configurations, and to the large mass splitting between the two ground states with $$I(J^P)=0(0^+)$$ I ( J P ) = 0 ( 0 + ) and $$I(J^P)=1(0^+)$$ I ( J P ) = 1 ( 0 + ) . We calculate their strong decay amplitudes into the $${\bar{D}}^{(*)}K^{(*)}$$ D ¯ ( ∗ ) K ( ∗ ) channels with the wave functions from the mass spectrum calculation and the quark-interchange method. We examine the interpretation of the recently observed $$X_0(2900)$$ X 0 ( 2900 ) as a tetraquark state. The mass and decay width of the $$I(J^P)=1(0^+)$$ I ( J P ) = 1 ( 0 + ) state are $$M=2941$$ M = 2941 MeV and $$\Gamma _X=26.6$$ Γ X = 26.6 MeV, respectively, which indicates that it might be a good candidate for $$X_0(2900)$$ X 0 ( 2900 ) . Meanwhile, we also obtain an isospin partner state $$I(J^P)=0(0^+)$$ I ( J P ) = 0 ( 0 + ) with $$M=2649$$ M = 2649 MeV and $$\Gamma _{X\rightarrow {\bar{D}} K}=48.1$$ Γ X → D ¯ K = 48.1 MeV, respectively. Future experimental search for X(2649) will be very helpful.

Newly observed X(4630): a new charmoniumlike molecule

“…In the study of the hidden-charmed decays, we adopt the quark-interchange model, which is introduced in Refs. [15,[45][46][47][48][49][50][51][52]. The onegluon-exchange (OGE) potential V i j (q 2 ) is a good approxi-…”

“…In our calculation, we adopt the quark-interchange model, which is introduced in Refs. [18][19][20][21][22][23][24][25]. In this model, the scattering amplitude for (c s) + (cs) → (cc) + (s s) can be decomposed at quark level.…”

Mass spectra and decays of open-heavy tetraquark states

“…Those works show X 0 (2900) is the bound state of D * K * , while X 1 (2900) seems not a molecular state [38]. In addition, the results based on the QCD sum rules [42][43][44], relativistic/non-relativistic quark models [45,46], and chromomagnetic interaction models [47] indicate both X 0 (2900) and X 1 (2900) are compact tetraquark states.…”

Studying the $${\bar{D}}_1K$$ molecule in the Bethe–Salpeter equation approach

“…Thus, the discovery of X 0 (2900) and X 1 (2900) have drawn a lot of attentions. The X 0 (2900) can be interpreted as a csūd compact tetraquark both in the universal quark mass picture [8] and in the quark model [9], but not within an extended relativized quark model [10]. In Ref.…”