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 (45)

• Newly observed exotic doubly charmed meson $T_{cc}^{+}$
• Magnetic dipole moments of the hidden-charm pentaquark states: $P_c(4440)$, $P_c(4457)$ and $P_{cs}(4459)$
• Magnetic dipole moments of the $T_{cc}^{+}$ and $Z_V^{++}$ tetraquark states
• Spectrum of the Hidden-Bottom and the Hidden-Charm/Strange Exotics in the Dynamical Diquark Model
• New scalar resonance $X_0(2900)$ as a ${\overline{D}}^{\ast }{K}^{\ast }$ molecule: Mass and width
• Investigation of magnetic moment of $P_{cs}(4338)$ and $P_{cs}(4459)$ pentaquark states
• Fully-strange tetraquark $ss\bar{s}\bar{s}$ spectrum and possible experimental evidence
• Molecular Interpretation of $X(3960)$ as $D_s^{+}{D}_s^{-}$ State
• Magnetic dipole moment of the $Z_{cs}(3985)$ state: diquark-antidiquark and molecular pictures
• The newly observed $Z_{cs}(3985{)}^{-}$ state: in vacuum and a dense medium
• Electromagnetic properties of doubly heavy pentaquark states
• On the structures of new scalar resonances $T_{cs0}^a(2900{)}^{++}$ and $T_{cs0}^a(2900{)}^0$
• Vector resonance $X_1(2900)$ and its structure
• Modeling the resonance $T_{cs0}^a(2900{)}^{++}$ as a hadronic molecule $D^{\ast +}{K}^{\ast +}$
• Magnetic dipole moments of the $Z_c(4020{)}^{+}$, $Z_c(4200{)}^{+}$, $Z_{cs}(4000{)}^{+}$ and $Z_{cs}(4220{)}^{+}$ states in light-cone QCD
• Magnetic moments of the doubly charged axial-vector $T_{cc}^{++}$ states
• Semileptonic and nonleptonic decays of the axial-vector tetraquark $T_{bb;\overline{u}\overline{d}}^{-}$
• Electromagnetic form factors of the $B_c$-like tetraquarks: molecular and diquark-antidiquark pictures
• Exploring the magnetic dipole moments of $T_{QQ\bar{q}\bar{s}}$ and $T_{QQ\bar{s}\bar{s}}$ states in the framework of QCD light-cone sum rules
• Stable scalar tetraquark $T_{bb;\bar{u}\bar{d}}^{-}$
• Improved XTZ masses and mass ratios from Laplace Sum Rules at NLO
• Partial decay widths of $\varphi (2170)$ to kaonic resonances
• Resonance $X(3960)$ as a hidden charm-strange scalar tetraquark
• Is the resonance $X_0(2900)$ a ground-state or radially excited scalar tetraquark $[ud][\overline{c}\overline{s}]$?
• Resonance $X(4630)$
• Magnetic moments of the vector hidden-charmed tetraquark states
• Higher strangeonium decays into light flavor baryon pairs like $\Lambda \bar{\Lambda }$, $\Sigma \bar{\Sigma }$, and $\Xi \bar{\Xi }$
• Heavy-light hybrid mesons with different spin-parities
• $X$ structures in $B^{+}\to J/\psi \varphi K^{+}$ as one-loop and double-triangle threshold cusps
• Magnetic and quadrupole moments of the $Z_c(4020{)}^{+}$, $Z_c(4050{)}^{+}$, and $Z_c(4600{)}^{+}$ states in the diquark-antidiquark picture
• Axial-vector and pseudoscalar tetraquarks $[ud][\bar{c}\bar{s}]$
• Universal non-resonant explanation to charmoniumlike structures $Z_c(3885)$ and $Z_c(4025)$
• Investigation of ${\Delta }^0{\Delta }^0$ dibaryon in QCD
• Possible Molecular Explanation for the Resonance $Y(4500)$
• Modifications on parameters of $Z(4430)$ in a dense medium
• The ground states of hidden-charm tetraquarks and their radial excitations
• Investigation of Mass and Decay Characteristics of the Light-Strange Tetraquark
• Strong decays of the vector tetraquark states with the masses about $4.5\mathrm{GeV}$ via the QCD sum rules
• 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
• Structural dissection of hadronic molecules: The $D^{(\ast )}{\bar{K}}^{(\ast )}$ family under QCD light-cone 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
• Charting doubly strange hidden-charm pentaquarks: An electromagnetic mapping of spin-$\frac{1}{2}$ and $\frac{3}{2}$ states
• Hadronic molecule model for the doubly charmed state $T_{cc}^{+}$