An overview of $XYZ$ new particles

Abstract

In the past decade, more and more charmoniumlike and bottomoniumlike states have been reported in experiments, which have led us to extensive discussions on the underlying structure of these states. In this review paper, we briefly summarize the experimental and theoretical status of these observed states.

Invited review for Chinese Science Bulletin. 14 pages, 4 tables, 3 figures. More reference added

References in corpus (48)

• Observation of a resonance-like structure in the pi^+- psi' mass distribution in exclusive B-->K pi^+- psi' decays
• Observation of Two Resonant Structures in e+e- to pi+ pi- psi(2S) via Initial State Radiation at Belle
• Measurement of e^+e^- to pi^+pi^-J/psi Cross Section via Initial State Radiation at Belle
• Higher Charmonia and X,Y,Z states with Screened Potential
• Evidence for a Narrow Near-Threshold Structure in the $J/\psi \varphi$ Mass Spectrum in $B^{+}\to J/\psi \varphi K^{+}$ Decays
• Observation of a near-threshold enhancement in the e+e- -->Lambda_c+Lambda_c- cross section using initial-state radiation
• Can the X(3872) be a 1^{++} four-quark state?
• X(3872) and Other Possible Heavy Molecular States
• Pion Interactions in the X(3872)
• Are Y(4260) and {\rm Z${}_2^{+}$(4250)} ${\mathrm{D}}_1\mathrm{D}$ or ${\mathrm{D}}_0{\mathrm{D}}^{\ast }$ Hadronic Molecules?
• Is X(3872) {\sl Really} a Molecular State?
• Is X(3872) a molecule?
• Search for new charmonium states in the processes e+ e- --> J/psi D(*) D(*) at sqrt{s} ~ 10.6 GeV
• Observation of anomalous Upsilon(1S)pi+pi- and Upsilon(2S)pi+pi- production near the Upsilon(5S) resonance
• Reconciling the X(3872) with the near-threshold enhancement in the D^0\bar{D}^{*0} final state
• Hadronic molecule structure of the Y(3940) and Y(4140)
• The Vector and Axial-Vector Charmonium-like States
• Measurement of the near-threshold $e^{+}{e}^{-}\to D\bar{D}$ cross section using initial-state radiation
• Evidence that the Y(4660) is a f_0(980)psi' bound state
• Is Z^+(4430) a loosely bound molecular state?
• Confirming the molecular nature of the $Z_b(10610)$ and the $Z_b(10650)$
• Isospin breaking, coupled-channel effects, and X(3872)
• Observation of $\psi (4415)\to D\bar{D}{}_2^{\ast }(2460)$ decay using initial-state radiation
• $Z^{+}(4430)$ as a $D_1^{\prime }{D}^{\ast }$ ($D_1{D}^{\ast }$) molecular state
• Effects of S-wave thresholds
• Canonical Charmonium Interpretation for Y(4360) and Y(4660)
• Ambiversion of X(3872)
• Threshold effect and π^\pm ψ(2S) peak
• Possible Molecular States of $D_s^{\ast }{\bar{D}}_s^{\ast }$ System and Y(4140)
• The hidden charm decay of Y(4140) by the rescattering mechanism
• A Uniform Description of the States Recently Observed at B-factories
• Light Pseudoscalar Meson and Heavy Meson Scattering Lengths
• X(3872) in lattice QCD with exact chiral symmetry
• Spectra and decays of hybrid charmonia
• Interpretations for the X(4160) observed in the double charm production at B factories
• Nonresonant explanation for the Y(4260) structure observed in the $e^{+}{e}^{-}\to J/\psi {\pi }^{+}{\pi }^{-}$ process
• The bound state problem of S-wave heavy quark meson-aitimeson systems
• Can the ${\pi }^{+}{\chi }_{c1}$ resonance structures be $D^{\ast }{\bar{D}}^{\ast }$ and $D_1\bar{D}$ molecules?
• Isospin properties of the X state near the D {\bar D}^{*} threshold
• Weakly-bound Hadronic Molecule near a 3-body Threshold
• Possible psi(5S), psi(4D), psi(6S) and psi(5D) signals in Lambda(c)-antiLambda(c)
• The line shape of the radiative open-charm decay of Y(4140) and Y(3930)
• Does the enhancement observed in $\gamma \gamma \to D\bar{D}$ contain two $P$-wave higher charmonia?
• Line Shapes of the Z(4430)
• Bottomed Analog of Z+(4433)
• Relativistic description of heavy tetraquarks
• The process $\epem\to J/ ψX(3940)$ at $\sqrt{s}=10.6$ GeV in the framework of light cone formalism
• Understanding the newly observed Y(4008) by Belle

Cited by in corpus (123)

• The hidden-charm pentaquark and tetraquark states
• An updated review of the new hadron states
• Scattering processes and resonances from lattice QCD
• Identifying exotic hidden-charm pentaquarks
• Towards exotic hidden-charm pentaquarks in QCD
• Strong LHCb evidence supporting the existence of the hidden-charm molecular pentaquarks
• Relating the finite-volume spectrum and the two-and-three-particle $S$ matrix for relativistic systems of identical scalar particles
• Weak decays of heavy hadrons into dynamically generated resonances
• Exotic tetraquark states with the $qq\bar{Q}\bar{Q}$ configuration
• QCD Sum Rules Approach to the $X,Y$ and $Z$ States
• X(3872) and Y(4140) using diquark-antidiquark operators with lattice QCD
• Determination of spin and parity of the $Z_c(3900)$
• Study of the $Z_c^{+}$ channel using lattice QCD
• Observation of a neutral charmoniumlike state $Z_c(4025{)}^0$ in $e^{+}{e}^{-}\to (D^{\ast }{\bar{D}}^{\ast }{)}^0{\pi }^0$
• Systematics of the heavy flavor hadronic molecules
• Mass spectra of Zc and Zb exotic states as hadron molecules
• Constructing $J/\psi$ family with updated data of charmoniumlike $Y$ states
• Observation of a Neutral Structure near the $D{\bar{D}}^{\ast }$ Mass Threshold in $e^{+}{e}^{-}\to (D{\bar{D}}^{\ast }{)}^0{\pi }^0$ at $\sqrt{s}$ = 4.226 and 4.257 GeV
• Strong decay mode $J/\psi p$ of hidden charm pentaquark states $P_c^{+}(4380)$ and $P_c^{+}(4450)$ in ${\Sigma }_c{\bar{D}}^{\ast }$ molecular scenario
• Charm-beauty meson bound states from $B(B^{\ast })D(D^{\ast })$ and $B(B^{\ast })\bar{D}({\bar{D}}^{\ast })$ interaction
• Heavy molecules and one-$\sigma /\omega$-exchange model
• Searching for possible ${\Omega }_c-$like molecular states from ${\Xi }_c^{\ast }\bar{K}/{\Xi }_c{\bar{K}}^{\ast }/{\Xi }_c^{\prime }{\bar{K}}^{\ast }$ interaction
• Decoding the $X(5568)$ as a fully open-flavor $su\bar{b}\bar{d}$ tetraquark state
• General considerations on the nature of $Z_b(10610)$ and $Z_b(10650)$ from their pole positions
• Understanding the internal structures of the $X(4140)$, $X(4274)$, $X(4500)$ and $X(4700)$
• Zc(4200)+ decay width as a charmonium-like tetraquark state
• XYZ-like Spectra from Laplace Sum Rule at N2LO in the Chiral Limit
• Probing new types of $P_c$ states inspired by the interaction between an $S$-wave charmed baryon and an anticharmed meson in a $\bar{T}$ doublet state
• Systematic studies of charmonium-, bottomonium-, and $B_c$-like tetraquark states
• Spectrum and rearrangement decays of tetraquark states with four different flavors
• Form factors of two-hadron states from a covariant finite-volume formalism
• What can we learn from the electromagnetic properties of hidden-charm molecular pentaquarks with single strangeness?
• A tetraquark or not a tetraquark: A holography inspired stringy hadron (HISH) perspective
• $Z_{cs}(3985{)}^{-}$: a strange hidden-charm tetraquark resonance or not?
• Emergence of molecular-type characteristic spectrum of hidden-charm pentaquark with strangeness embodied in the $P_{\psi s}^{\Lambda }(4338)$ and $P_{cs}(4459)$
• Hadronic Loops versus Factorization in EFT calculations of $X(3872)\to {\chi }_{cJ}{\pi }^0$
• $K^{\ast }$ mesons with hidden charm arising from $KX(3872)$ and $K{Z}_c(3900)$ dynamics
• Possible triple-charm molecular pentaquarks from ${\Xi }_{cc}{D}_1/{\Xi }_{cc}{D}_2^{\ast }$ interactions
• Exotic triple-charm deuteron-like hexaquarks
• Doubly charmed molecular pentaquarks
• Hidden-charm pentaquarks with triple strangeness due to the ${\Omega }_c^{(\ast )}{\bar{D}}_s^{(\ast )}$ interactions
• Strong decays of the $XYZ$ states
• Magnetic and quadrupole moments of the $Z_c(3900)$
• Exotic double-charm molecular states with hidden or open strangeness and around $4.5\sim 4.7$ GeV
• Influence of threshold effects induced by charmed meson rescattering
• Is the newly reported $X(5568)$ a $B\bar{K}$ molecular state?
• Unified Fano-like interference picture for charmonium-like states $Y(4008)$, $Y(4260)$ and $Y(4360)$
• Investigating new type of doubly-charmed molecular tetraquarks composed of the charmed meson in $H$-doublet and the charmed meson in $T$-doublet
• Heavy Flavour Physics and CP Violation at LHCb: a Ten-Year Review
• Correlation of the hidden-charm molecular tetraquarks and the charmoniumlike structures existing in the $B\to XYZ+K$
• Exploring the electromagnetic properties of the ${\Xi }_c^{(\prime ,\ast )}{\bar{D}}_s^{\ast }$ and ${\Omega }_c^{(\ast )}{\bar{D}}_s^{\ast }$ molecular states
• Newly observed $X(4630)$: a new charmoniumlike molecule
• Surveying the mass spectra and the electromagnetic properties of the ${\Xi }_c^{(\prime ,\ast )}{D}^{(\ast )}$ molecular pentaquarks
• Pentaquark states with the $QQQq\bar{q}$ configuration in a simple model
• Interference effect as resonance killer of newly observed charmoniumlike states $Y(4320)$ and $Y(4390)$
• Production of the superheavy baryon ${\Lambda }_{c\bar{c}}^{\ast }(4209)$ in kaon-induced reaction
• Triple-charm molecular states composed of $D^{\ast }{D}^{\ast }D$ and $D^{\ast }{D}^{\ast }{D}^{\ast }$
• Spectroscopic survey of higher-lying states of $B_c$ meson family
• Newly observed $a_0(1817)$ as the scaling point of constructing the scalar meson spectroscopy
• A new group of doubly charmed molecule with $T$-doublet charmed meson pair
• Study on the rare decays of $Y(4630)$ induced by final state interactions
• Photoproduction of the charged charmoniumlike $Z_c^{+}(4200)$
• Where are $3P$ and higher $P-$wave states in the charmonium family?
• Using $X(3823)\to J/\psi {\pi }^{+}{\pi }^{-}$ to identify coupled-channel effects
• Probing the electromagnetic properties of the ${\Sigma }_c^{(\ast )}{D}^{(\ast )}$-type doubly charmed molecular pentaquarks
• Higher molecular $P_{\psi s}^{\Lambda /\Sigma }$ pentaquarks arising from the ${\Xi }_c^{(\prime ,\ast )}{\bar{D}}_1/{\Xi }_c^{(\prime ,\ast )}{\bar{D}}_2^{\ast }$ interactions
• Double-charm heptaquark states composed of two charmed mesons and one nucleon
• Radiative decays and magnetic moments of the predicted $B_c$-like molecules
• Probing the $XYZ$ states through radiative decays
• Understanding $B^{-}\to X(3823)K^{-}$ via rescattering mechanism and predicting $B^{-}\to {\eta }_{c2}{(}^1{D}_2)/{\psi }_3{(}^3{D}_3)K^{-}$
• New type of doubly charmed molecular pentaquarks containing most strange quarks: Mass spectra, radiative decays, and magnetic moments
• Lattice QCD study of the elastic and transition form factors of charmed baryons
• Refining radiative decay studies in singly heavy baryons
• Two-Body Strong Decay of the 2P and 3P Charmonium states
• Searching for hidden-charm baryonium signals in QCD sum rules
• Search for a strangeonium-like structure $Z_s$ decaying into $\varphi \pi$ and a measurement of the cross section $e^{+}{e}^{-}\to \varphi \pi \pi$
• The Strong Decays of X(3940) and X(4160)
• Photoproduction of the $f_2^{\prime }(1525)$ and $K_2^{\ast }(1430)$
• One way to verify the molecular picture of exotic hadrons --from $DK$ to $DDK/D{\bar{D}}^{(\ast )}K$
• Possible bound states with hidden bottom from ${\bar{K}}^{(\ast )}{B}^{(\ast )}{\bar{B}}^{(\ast )}$ systems
• Colloquium: Hadron Production in Open-charm Meson Pair at $e^{+}{e}^{-}$ Collider
• Predicting exotic molecular states composed of nucleon and P-wave charmed meson
• How higher charmonia shape the puzzling data of the $e^{+}{e}^{-}\to \eta J/\psi$ cross section
• Prediction of new states from $D^{(\ast )}{B}^{(\ast )}{\bar{B}}^{(\ast )}$ three-body interactions
• Strong decay constants of heavy tensor mesons in light cone QCD sum rules
• Understanding close-lying exotic charmonia states within QCD sum rules
• Investigating the M1 radiative decay behaviors and the magnetic moments of the predicted triple-charm molecular-type pentaquarks
• Charged charmoniumlike structures in the $e^{+}{e}^{-}\to \psi (3686){\pi }^{+}{\pi }^{-}$ process based on the ISPE mechanism
• Exploring the mass spectrum and the electromagnetic properties of the possible ${\Xi }_{cc}{K}^{(\ast )}$ and ${\Xi }_{cc}{\bar{K}}^{(\ast )}$ molecules
• Photoproduction of $a_2(1320)$ in a Regge model
• Higher strangeonium decays into light flavor baryon pairs like $\Lambda \bar{\Lambda }$, $\Sigma \bar{\Sigma }$, and $\Xi \bar{\Xi }$
• Production of the charmoniumlike state $Y(4220)$ through the $p\bar{p}\to Y(4220){\pi }^0$ reaction
• Magnetic moment of $X_Q$ state with $J^{PC}=1^{+\pm }$ in light cone QCD sum rules
• Triply heavy baryon spectroscopy revisited
• New type of hydrogenlike charm-pion or charm-kaon matter
• Spectroscopic Properties of Double-Strangeness Molecular Tetraquarks
• Probing exotic $J^{PC}$ resonances from deeply bound charmoniumlike molecules: Insights for identifying exotic hadrons
• Possible Molecular Explanation for the Resonance $Y(4500)$
• Discovery potential for the neutral charmoniumlike $Z^0(4200)$ by $\bar{p}p$ annihilation
• Predictions of super-exotic heavy mesons from $K^{\ast }{B}^{\ast }{B}^{\ast }$ interactions
• Phase shifts of the light pseudoscalar meson and heavy meson scattering in heavy meson chiral perturbation theory
• Possible molecules of triple-heavy pentaquarks within the extended local hidden gauge formalism
• Semileptonic decay of $B_c^{-}$ into $X(3930)$, $X(3940)$, $X(4160)$
• Electromagnetic properties of possible triple-charm molecular hexaquarks
• Unveiling the Composition of the Single-Charm Molecular Pentaquarks: Insights from Radiative Decay and Magnetic Moment
• Electromagnetic characteristics as probes into the inner structures of the predicted ${\Xi }_c^{{(}^{\prime },\ast )}{D}_s^{(\ast )}$ molecular states
• The Production of $X(3940)$ and $X(4160)$ in $B_c$ decays
• Proper constituent gluon mass as the final piece to construct hybrid mesons
• Exploration of charmed pentaquarks
• Strong decays of $a_0$, $f_0$, $f_2$, and $K_2^{\ast }$ resonances as dynamically generated states of two vector mesons
• An alternative way to decipher the nature of the doubly charmed tetraquark $T_{cc}(3875{)}^{+}$: its antiparticle $T_{\bar{c}\bar{c}}(3875{)}^{-}$ photoproduction off nuclei near threshold
• Predicting possible molecular states of nucleons with ${\Xi }_c$, ${\Xi }_c^{\ast }$, and ${\Xi }_c^{\prime }$
• Dynamically generated states from the $\eta K^{\ast }{\bar{K}}^{\ast }$, $\pi K^{\ast }{\bar{K}}^{\ast }$, and $K{K}^{\ast }{\bar{K}}^{\ast }$ systems within the fixed-center approximation
• Observation of pentaquark states and perspectives of further studies
• Coupled-channel study of $4S$-$3D$ mixing dynamics in $\psi (4220)$ and $\psi (4380)$
• Non-$D\bar{D}$ Decays into Light Meson Pairs of the $D$-Wave Charmonium ${\psi }_3(3842)$
• Five-flavor molecular pentaquarks in the ${\Xi }_b^{(\prime ,\ast )}{\bar{D}}^{(\ast )}$ and ${\Xi }_c^{(\prime ,\ast )}{B}^{(\ast )}$ systems
• Prospects for observing the missing $2D$ and $1F$ charmonium states around 4 GeV
• Charged charmonium-like structures and the initial single chiral particle emission mechanism
• The dynamically generated $h_1$ state by the $K^{\ast }{\bar{K}}^{\ast }$ interaction and its $K_1(1270)\bar{K}$ and $b_1(1235)\pi$ decays
• Investigating topped hadrons to probe the boundaries of the potential model
• Predicting charmed-strange molecular tetraquarks with $K^{(\ast )}$ and $T$-doublet charmed or anticharmed meson
• Systematic exploration of triply heavy tetraquarks: spectroscopic and decay characteristics