Four-quark exotic mesons

Abstract

We review our investigations devoted to the analysis of the resonances $Z_c(3900)$, $Z_c(4430)$, $Z_c(4100)$, $X(4140)$, $X(4274)$, $a_1(1420)$ , $Y(4660)$, $X(2100)$, $X(2239)$ and $Y(2175)$ discovered in various processes by Belle, BaBar, BESIII, D0, CDF, CMS, LHCb and COMPASS collaborations. These resonances are considered as serious candidates to four-quark (tetraquark) exotic mesons. We treat all of them as diquark-antidiquark states with relevant spin-parities, find their masses and couplings, as well as explore their dominant strong decay channels. Calculations are performed in the context of the QCD sum rule method. Thus, the spectroscopic parameters of the tetraquarks are evaluated using the two-point sum rules. For computations of the strong couplings $G_{T{M}_1{M}_2}$, corresponding to the vertices $T{M}_1{M}_2$ and necessary to find the partial widths of the strong decays $T\to M_1{M}_2$, we employ either the three-point or full/approximate versions of the QCD light-cone sum rules methods. Obtained results are compared with available experimental data, and with predictions of other theoretical studies.

56 Pages, 14 Figures and 8 Tables. A review based on arXiv:1706.01216, 1812.10094, 1703.10323, 1711.05977, 1805.04705, 1906.04061, 1911.09743

Cited by in corpus (16)

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• Partial decay widths of $\varphi (2170)$ to kaonic resonances
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• Strong decays of the vector tetraquark states with the masses about $4.5\mathrm{GeV}$ via the QCD sum rules
• Investigation of Mass and Decay Characteristics of the Light-Strange Tetraquark
• The ground states of hidden-charm tetraquarks and their radial excitations
• Electromagnetic properties of the $D{\bar{D}}^{\ast }K$ molecular hexaquark state
• Near-threshold structures in the $D_s^{+}{D}_s^{-}$ mass distribution of the decay $B^{+}\to D_s^{+}{D}_s^{-}{K}^{+}$
• Two-body strong decays of the hidden-charm tetraquark molecular states via the QCD sum rules
• Analytic electromagnetic signatures of compact pentaquark structure: A multi-current QCD light-cone sum rules analysis of the $P_{\psi s}^{\Lambda }$ states
• Structural dissection of hadronic molecules: The $D^{(\ast )}{\bar{K}}^{(\ast )}$ family under QCD light-cone sum rules
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