Egzotik Hadronlar

Year 2018, Volume: 30 Issue: 1, 77 - 93, 31.03.2018

Jale Yılmazkaya Süngü , Elşen Veli

https://doi.org/10.7240/marufbd.338529

Abstract

Son yıllarda yapılan yüksek enerji
fiziği deneylerinde Standart Model çerçevesinde bilinen parçacık yapıları
dışında yeni parçacıklar dedekte edilmiştir. Bu gelişmeler, Standart Model
ötesi fizik açısından oldukça önemlidir. İç yapısı nedeniyle egzotik parçacık
diye adlandırılan bu parçacıkların hem deneysel, hemde teorik çalışmalara
farklı bir yön vereceği düşünülmektedir. Bu parçacıklar bugüne kadar tam olarak
açıklanamayan madde-antimadde asimetrisi, evrenin oluşumu, karanlık madde,
karanlık enerji, nötron yıldızlarının iç yapısı gibi pekçok konu hakkında
ipuçları verebilir. Ayrıca bu parçacıkların keşfi son yıllarda hadron
spektroskopisine olan ilgiyi oldukça artırmıştır. Bu çalışmada, bugüne kadar
tespit edilen egzotik parçacıkların kütle, kuantum sayıları, bozunma
genişlikleri gibi temel özellikleri hakkında bilgi sunulacaktır.

Keywords

Egzotik parçacık, gluontopu, hibritler, tetrakuark, pentakuark, hegzakuark, molekül yapılar

Exotic Hadrons

Abstract

In recent years, in the high energy
physics experiments, new particles have been detected except for known particle
structures in the Standard Model framework. These developments are also very
important in terms of physics beyond the Standard Model. It is thought that
particles in this different structure, which is called exotic particle due to
internal structure, will give a different direction to both experimental and
theoretical studies. These particles can give clues on the asymmetry of
matter-antimatter, the formation of the universe, the dark matter, the dark
energy, the inner structure of neutron stars, and so forth. Moreover, the
discovery of these particles has widely increased the interest in hadron
spectroscopy in recent years. In this work, information on the basic properties
of exotic particles, such as mass, quantum numbers, and decay widths, which are
detected until now, will be presented.

Keywords

Exotic particle, glueball, hybrids, tetraquark, pentaquark, hexaquark, molecular structures, baryonium

References

• [1] Gell-Mann, M. (1964). A schematic model of baryons and mesons. Phys. Lett. 8, 214.
• [2] Olive, K.A. et al. [Particle Data Group] (2015). Non-qq ̅ mesons. Chin. Phys. C38, 090001.
• [3] Besson, D. et al., [CLEO Collaboration] (2003). Observation of a narrow resonance of mass 2.46 GeV/c^2 decaying to D_s^(*+) π^0 and confirmation of the D_sJ^* (2317) state, Phys. Rev. D68, 032002, [Erratum: Phys. Rev. D75, 119908 (2007)].
• [4] Choi, S.K. et al., [Belle Collaboration] (2003). Observation of a new narrow charmonium state in exclusive B^±→ K^± π^+ π^- J/ψ decays, Phys. Rev. Lett. 91, 262001.
• [5] Abazov, V. M. et al., [D0 Collaboration] (2016). Evidence for a B_s^0 〖π 〗^± state, Phys.Rev.Lett., 117 (2) 022003.
• [6] Acosta, D. et al. [CDF II Collaboration] (2004). Observation of the narrow state X(3872)→ J/ψ π^+ π^- in p ̅p collisions at √s= 1.96 GeV. Phys.Rev.Lett. 93, 072001.
• [7] Aaij, R. et al. [LHCb Collaboration] (2015). Observation of J/ψp resonances consistent with pentaquark states Λ_b^0→ J/ψK^- p decays. Phys.Rev.Lett. 115, 072001.
• [8] Ablikim, M. et al. [BESIII Collaboration] (2017). Precise measurement of the e^+ e^-→π^+ π^- J/ψ cross section at center- of- mass energies from 3.77 to 4.60 GeV. Phys.Rev.Lett. 118, 092001.
• [9] Chen, H. et. al. (2017). A review of the open charm and open bottom systems, Reports on Progress in Physics, 80, 7.
• [10] Brambilla, N. et al. (2011). Heavy quarkonium: progress, puzzles, and opportunities. Eur. Phys. J. C71, 1534.
• [11] https://en.wikipedia.org
• [12] Fritzsch, H. and Gell-Mann, M. (1972). Current algebra: Quarks and what else? eConf, 11 C720906V2, 135.
• [13] Fritzsch, H. and Minkowski, P. (1975). Psi resonances, gluons and the Zweig Rule, Nuovo Cim. A 30, 393.
• [14] Dzierba, A.R., Meyer, C.A. and Swanson, E.S. (2000). The search for QCD exotics. Am.Sci. 88, 406.
• [15] Robson, D. (1977). A basic guide for the glueball spotter. Nucl.Phys. B130, 328.
• [16] https://en.wikipedia.org/wiki/Glueball
• [17] Klempt, E and Zaitsev, A. (2007). Glueballs, hybrids, multiquarks. Experimental facts versus QCD inspired concepts. Phys.Rept. 454, 1–202.
• [18] Lee, W. and Weingarten, D. (2000). Scalar quarkonium masses and mixing with the lightest scalar glueball. Phys.Rev. D61, 014015.
• [19] Bali, G.S. et al. [UKQCD Collaboration] (1993). A Comprehensive lattice study of SU(3) glueballs . Phys. Lett. B 309, 378.
• [20] Morningstar, C.J. and Peardon, M.J. (1997). Efficient glueball simulations on anisotropic lattices. Phys. Rev. D56, 4043.
• [21] Chen, Y. et al. (2006). Glueball spectrum and matrix elements on anisotropic lattices. Phys.Rev. D73, 014516.
• [22] Loan, M. and Ying, Y. (2006). Sizes of lightest glueballs in SU(3) lattice gauge theory. Prog. Theor. Phys. 116, 169.
• [23] Jaffe, R.L. (1977). Perhaps a Stable Dihyperon? Phys.Rev. Lett. 38 (5) 195.
• [24] Swanson, E.S. (2006). The New heavy mesons: A status report, Phys.Rept. 429, 243-305.
• [25] Chen, H.X. et al. (2016). The hidden-charm pentaquark and tetraquark states. Phys.Rept. 639, 1-121.
• [26] Cotugno, G., Faccini, R., Polosa, A.D. and Sabelli, C. (2010). Charmed baryonium. Phys.Rev.Lett. 104 (13) 132005.
• [27] Aaltonen, T. et al. [CDF Collaboration] (2009). Evidence for a narrow near-threshold structure in the J/ψϕ mass spectrum in B^+→J/ψϕK^+ decays. Phys.Rev.Lett. 102, 242002.
• [28] Ali, A., Hambrock, C. and Aslam, M.J. (2010). Tetraquark interpretation of the BELLE data on the anomalous γ (1S) π^+ π^- and γ (2S) π^+ π^-production near the Υ(5S) resonance. Phys.Rev.Lett. 104 (16) 162001.
• [29] Choi, S.K. et al. [Belle Collaboration] (2008). Observation of a resonance-like structure in the π^± ψ^' mass distribution in exclusive B→Kπ^± ψ^' decays. Phys.Rev. Lett. 100, 142001.
• [30] Aaij, R. et al. [LHCb collaboration] (2014). Observation of the resonant character of the Z(4430) state. Phys.Rev.Lett. 112, 222002.
• [31] Ablikim, M. et al. [BESIII collaboration] (2013). Observation of a charged charmoniumlike structure in e^+ e^-→π^+ π^- J/ψ at √s=4.26 GeV. .Phys.Rev.Lett. 110 (25) 252001.
• [32] Liu, Z. et al. [Belle collaboration] (2013). Study of e^+ e^-→π^+ π^- J/ψ and observation of a charged charmoniumlike state at Belle, Phys.Rev.Lett. 110 (25) 252002.
• [33] Aaij, R. et al. [LHCb Collaboration] (2017). Observation of J/ψφ structures consistent with exotic states from amplitude analysis of B^+→ J/ψϕK^+ decays. Phys Rev Lett. 118, 022003 .
• [34] Abazov, V.M. et al.(2016). Evidence for a B_s^0 〖π 〗^± state D0 Collaboration. Phys.Rev.Lett. 117 (2) 022003.
• [35] Aaij, R. et al. [LHCb Collaboration] (2016). Search for structure in the B_s^0 〖π 〗^± invariant mass spectrum. Phys.Rev.Lett. 117 (15) 152003, Addendum: Phys.Rev.Lett. 118 (2017) no.10, 109904.
• [36] Barnes, T. et al. (2003). Implications of a DK molecule at 2.32 GeV. Phys.Rev. D68, 054006.
• [37] Liu, L. et al. (2013). Interactions of charmed mesons with light pseudoscalar mesons from lattice QCD and implications on the nature of the D_s0^* (2317). Phys.Rev. D87, 014508.
• [38] Guo, F.K., et al. (2017). Hadronic molecules. e-Print: arXiv:1705.00141 [hep-ph].
• [39] Ablikim, M. et al. [BESIII Collaboration] (2017). Evidence of two resonant structures in e^+ e^-→π^+ π^- h_c, Phys.Rev.Lett. 118, 092002.
• [40] May, B. et al. [ASTERIX Collaboration] (1990). Anti-proton proton annihilation at rest in H_2 gas into π^+ π^- π^0. Z. Phys. C46, 203.
• [41] Bertin, A. et al. (1998). Study of the f_0 (1500)/f_0 (1565) production in the exclusive annihilation n ̅p→π^+ π^- π^0 in flight. Phys.Rev. D 57, 55.
• [42] Pakhlova, G. et al. [Belle Collaboration] (2008). Observation of a near-threshold enhancement in the e^+ e^-→Λ_b Λ_c cross section using initial-state radiation. Phys.Rev. Lett. 101, 172001.
• [43] Cotugno, G. et al. (2010). Charmed baryonium. Phys.Rev.Lett. 104, 132005.
• [44] Guo, F.K. et al. (2010). Reconciling the X(4630) with the Y(4660). Phys.Rev. D 82, 094008.
• [45] Adlarson, P. et al. [WASA-at-COSY Collaboration] (2015). Measurement of the np→npπ^0 π^0 reaction in search for the recently observed d^* (2380) resonance. Phys.Lett. B 74, 325-332.
• [46] Lacock, P. et al. (1997). Hybrid mesons from quenched QCD. Phys.Lett. B401, 308.
• [47] Bernard, C. et al. (1997). Exotic mesons in quenched lattice QCD. Phys.Rev. D56, 7039.
• [48] Kuhn, J. (2004). Evidence for exotic mesons. AIP Conf.Proc. 717, 377-386.
• [49] Lu, M. et al. [E852 Collaboration] (2005). Exotic meson decay to ωπ^0 π^-. Phys.Rev.Lett. 94, 032002.
• [50] Chung, S.U. (2015). Recent COMPASS results and future prospects for ALICE Published in AIP Conf.Proc. 1654, 050009.
• [51] Alekseev, M.G. et al. (2010). Observation of a J^PC=1^(-+) exotic resonance in diffractive dissociation of 190GeV/c π^- into π^- π^- π^+. Phys.Rev.Lett. 104, 241803.
• [52] Amelin, D.V. et al. [VES Collaboration] (1995). Study of resonance production in diffractive reaction π^- A→π^+ π^- π^- A. Phys.Lett. B 356, 595.
• [53] Diakonov, D., Petrov V. and Polyakov, M. (1997). Exotic anti-decuplet of baryons: prediction from chiral solitons. Zeitschrift für Physik A Hadrons and Nuclei, 359 (3) 305–314.
• [54] Nakano, T. et al. [LEPS Collaboration] (2009). Evidence of the Θ^+ in the γd →K^+ K^- pn reaction. Phys. Rev. C.79 (2) 025210.
• [55] http://hyperphysics.phy-astr.gsu.edu/hbase/Particles/pquark.htm
• [56] Zavertyaev, M. [WA89 and COMPASS Collaborations] (2005). A search for pentaquark candidates in experiments WA89 and COMPASS. Nucl. Phys. A 755, 387-390.
• [57] Aubert, B. et al. [BaBar Collaboration] (2006). Search for the charmed pentaquark candidate 〖θ_c (3100)〗^0 in e^+ e^- annihilations at √s= 10.58 GeV. Phys.Rev. D73, 091101.
• [58] Mennessier, G., Narison, S. and Wang, X. G. (2010). The σ and f_0 (980) from K_e4⊕ππ scatterings data Phys.Lett. B 688, 59.
• [59] Ochs, W. (2013). The Status of glueballs. J.Phys.G 40, 043001.
• [60] Aitala, E.M. et al. [E791 Collaboration] (2001). Experimental evidence for a light and broad scalar resonance in D^+→π^- π^+ π^+ decay. Phys.Rev.Lett. 86, 770.
• [61] M. Ablikim et al. [BESIII Collaboration] (2017). Amplitude analysis of the χ_c1→η π^+ π^-decays. Phys.Rev. D95 (3) 032002.
• [62] Morningstar, C.J. and Peardon, M.J. (1999). The Glueball spectrum from an anisotropic lattice study. Phys.Rev. D60, 034509.
• [63] Achasov, N.N. (2000). On nature of scalar a_0 (980) and f_0 (980)mesons. Nucl.Phys. A675, 279C.
• [64] Oller, J.A. et al. (2003). Finite width effects in ϕ radiative decays. Nucl.Phys. A714, 161.
• [65] Sekihara, T., Kumano, S. (2015). Constraint on K ̅K compositeness of the a_0 (980) and f_0 (980) resonances from their mixing intensity. Phys.Rev. D92 (3) 034010.
• [66] Ablikim, M. et al. [BESIII Collaboration] (2015). Observation of the isospin-violating decay J/ψ→ϕπ^0 f_0 (980). Phys.Rev. D92 (1) 012007.
• [67] Hietala, J., Cronin-Hennessy, D., Pedlar, T. and Shipsey, I. (2015). Exclusive D_s semileptonic branching fraction measurements. Phys.Rev. D92 (1) 012009. [68] Aaij, R. et al. [LHCb Collaboration]. (2015). Study of the rare B_s^0 and B^0 decays into the π^+ π^- μ^+ μ^- final state. Phys.Lett.B 743, 46.
• [69] Li, J. et al. [Belle Collaboration] (2011). Observation of B_s^0→J/ψf_0 (980) and evidence for B_s^0→J/ψf_0 (1370). Phys.Rev.Lett. 106, 121802.
• [70] Uehara, A. (2009). High-statistics study of ηπ^0production in two-photon collisions. Phys.Rev. D80, 032001.
• [71] Silarski, M. and Moskal, P. for the COSY-11 collaboration. (2010). Study of the near threshold pp→pp〖K^+ K〗^- reaction in view of the 〖K^+ K〗^- final state interaction. Invited talk at the Excited QCD 2010 Workshop, 31 January-6 February, Stara Lesna, Slovakia.
• [72] Sanchez, P. del Amo. et al. [BaBar Collaboration] (2010). Measurement of D^0-▁D^0 mixing parameters using D^0→K_S^0 π^+ π^- and D^0→K_S^0 〖K^- K〗^+decays. Phys.Rev.Lett. 105, 081803.
• [73] Achasov, N.N. [KLOE Collaboration] (2003). Radiative decays of ϕ meson about nature of light scalar resonances. Nucl. Phys. A728, 425.
• [74] Mukherjee, T.K., et al. (2014). Chiral phase transition with mixing between scalar quarkonium and tetraquark. Phys.Rev. D89 (7) 076002.
• [75] Gutsche, T. et al. (2017). Role of scalar mesons in the beam asymmetry of pp ̅ and ΛΛ ̅ photoproduction at JLab. arXiv:1705.07002 [hep-ph].
• [76] Alde et al., D. [GAMS Collaboration] (1999). New results of the GAMS collaboration on meson spectroscopy. Phys.Atom.Nucl. 62, 1993-1998, Yad.Fiz. 62 (1999) 2160-2166. [77] Abele, et al. [Crystal Barrel Collaboration] (1996). Observation of f_0 (1500) decay into K_L K_L. Phys.Lett.B 385, 425.
• [78] Abe, K. et al. [Belle Collaboration] (2002). Study of three-body charmless B decays Phys.Rev. D65, 092005.
• [79] Aubert, B. et al. [BABAR Collaboration] (2004). Measurements of the branching fractions of charged B decays to K^± π^∓ π^± final states. Phys.Rev. D70, 092001.
• [80] Chung, S.U., Klempt, E. and Korner, J.G. (2002). SU(3) classification of p-wave ηπ and π systems. Eur. Phys. J. A 15, 539.
• [81] Zhang, R., Ding, Y.B., Li, X.Q. and Page, P.R. (2002). Molecular states and 1^(-+)exotic mesons. Phys.Rev. D65, 096005.
• [82] Alde, D. et al. [IHEP-IISN-LANL-LAPP Collaboration] (1988). Evidence for a 1^(-+) exotic meson. Phys.Lett.B 205, 397.
• [83] Aoyagi, H. et al. Study of the ηπ^- system in the π-p reaction at 6.3 GeV/c. Phys.Lett. B314, 246 (1993).
• [84] Abele, A. et al. [Crystal Barrel Collaboration] (1998). Exotic ηπ state in p ̅d annihilation at rest into π-π^0 ηp (spectator). Phys.Lett. B423, 175; (1999). 446, 349.
• [85] Adams, G.S. et al. [E852 Collaboration] (2007). Confirmation of the 1^(-+) meson exotics in the ηπ^0 System. Phys.Lett. B657, 27.
• [86] Azizi, K., Barsbay, B. and Sundu, H. Mass and residue of Λ(1405) as a hybrid baryon, arXiv:1705.10345 [hep-ph].
• [87] Hall, J.M.M. et al. (2015). Lattice QCD evidence that the Λ(1405) resonance is an antikaon-nucleon molecule, Phys. Rev. Lett. 114 (13) 132002.
• [88] Dalitz, R. and Tuan, S. (1959). A possible resonant state in pion-hyperon scattering, Phys.Rev.Lett. 2, 425.
• [89] Dalitz, R. and Tuan, S. (1960). The phenomenological description of K- nucleon reaction processes. Annals Phys. 10, 307.
• [90] Roca, L. and Oset, E. (2016). On the hidden charm pentaquarks in Λ_b→J/ψK^- p decay. Eur.Phys.J. C76 (11) 591.
• [91] Bazzi, M. et al. (2012). Kaonic hydrogen X-ray measurement in SIDDHARTA, Nucl.Phys. A881, 88-97.
• [92] Sumihama, M. et al. [LEPS Collaboration] (2006). The γp→K^+ Λ and γp → K^+ Σ^0 reactions at forward angles with photon energies from 1.5GeV to 2.4GeV. Phys.Rev. C73, 035214.
• [93] Moriya, K. et al. [CLAS Collaboration] (2013). Differential photoproduction cross sections of the Σ^0 (1385),Λ(1405) and Λ(1520). Phys.Rev. C 88, 045201. Addendum: [Phys. Rev. C 88 (4) 049902 (2013)].
• [94] Agakishiev, G. et al. [HADES Collaboration] (2013). Baryonic resonances close to the K ̅N threshold: the case of Λ(1405) in pp collisions. Phys.Rev. C87, 025201.
• [95] Cheng, H.Y., Chua, C.K. and Liu, K.F. (2015). Revisiting scalar glueballs. Phys.Rev. D92 (9) 094006.
• [96] Amsler, C. and Close, F.E. (1996). Is f^0 (1500) a scalar glueball? Phys. Rev. D53, 295.
• [97] Azhinenko, I.V. et al. [CERN-USSR Collaboration] (1984). Inclusive K^(*+) (890),K^(*+) (1430) and K^* (890) production in K^+ p interactions at 32GeV/c. Z.Phys. C25, 103.
• [98] Abele, A. et al. [Crystal Barrel Collaboration] (1997). Study of the π^0 π^0 η' final state in p ̅p annihilation at rest. Phys.Lett. B404 179-186.
• [99] Abele, A. et al. [Crystal Barrel Collaboration] (1998). p ̅p annihilation at rest into K_L K^± π^∓. Phys. Rev. D 57, 3860.
• [100] Ablikim, M. et al. [BES Collaboration] (2006). Partial wave analyses of J/ψ→γπ^+ π^- and γπ^0 π^0. Phys.Lett. B642, 441.
• [101] Ablikim, M. et al. [BESIII Collaboration] (2013). Partial wave analysis of J/ψ→γηη. Phys.Rev. D87 (9) 092009, Erratum: Phys.Rev. D87, 11, 119901.
• [102] Rai, A.K. Rathaud, D.P. (2015). The mass spectra and decay properties of dimesonic states, using the Hellmann potential. Eur.Phys. J. C75 (9) 462.
• [103] Adamo, A. et al. [OBELIX Collaboration] (1992). First physics results from OBELIX. Sov.J.Nucl.Phys. 55, 1732-1742, Yad.Fiz. 55, 3099-3121.
• [104] Close, F.E. and Page, P.R. (1995). The production and decay of hybrid mesons by flux-tube breaking. Nucl. Phys. B 443, 23.
• [105] Adams, G.S. et al. [CLEO Collaboration] (2011). Amplitude analyses of the decays χ_c1→ηπ^+ π^- and χ_c1→η^' π^+ π^-. Phys.Rev. D84 112009.
• [106] Ivanov, E. I. et al. [E852 Collaboration] (2001). Observation of exotic meson production in the reaction π^- p→η^' π^- p at 18 GeV/c. Phys.Rev.Lett. 86, 3977.
• [107] Khokhlov, Y.A. et al. [VES Collaboration] (2000). Study of X(1600) 1^(-+) hybrid. Nucl.Phys.A 663, 596.
• [108] Amsler, C. et al. (2008). Review of particle physics. Phys.Lett. B 667, 1.
• [109] Pinder, C.N. [CRYSTAL BARREL Collaboration] (1997). Analysis of p ̅p→π^0 π^0 π^0 η for annihilation at rest in liquid and gaseous hydrogen targets. Nucl.Phys.Proc.Suppl. 56 (1) 154-159.
• [110] Kalashnikova, Y.S. (1994). If the ρ (1405) is the exotic 1^- (1^(-+)) hybrid, then where are the nonexotic ones? Nuovo Cim. A107, 2421-2424.
• [111] Klempt, E. and Zaitsev, A. (2007). Glueballs, hybrids, multiquarks. Experimental facts versus QCD inspired concepts. Phys. Rept. 454, 1.
• [112] Albaladejo, M. and Oller, J.A. (2008). Identification of a scalar glueball. Phys. Rev. Lett. 101, 252002.
• [113] Ghoul, H.A. et al. [GlueX Collaboration] (2017). Measurement of the beam asymmetry Σ for π^0 and η photoproduction on the proton at E_γ=9GeV. Phys.Rev. C95, 042201.
• [114] Ablikim, M. et al. [BESIII Collaboration] (2013). Partial wave analysis of J/ψ→γηη. Phys.Rev. D87 (9) 092009. Erratum: Phys.Rev. D87 (2013) 11, 119901.
• [115] Bicudo, P. et al. (2007). The BES f^0 (1810): A new glueball candidate. Eur.Phys.J. C52, 363.
• [116] Ablikim, M. et al. [BES Collaboration] (2006). Observation of a near-threshold enhancement in the mass spectrum from the doubly OZI suppressed decay J/ψ → γωφ. Phys. Rev. Lett. 96, 162002.
• [117] Ablikim, M. et al. [BESIII Collaboration] (2015). Amplitude analysis of the π^0 π^0 system produced in radiative J/ψ decays. Phys.Rev. D92, 052003.
• [118] Amelin, D.V. et al. (2005). Investigation of hybrid states in the VES experiment at the Institute for High Energy Physics. Phys.Atom.Nucl. 68, 359-371, Yad.Fiz. 68 (2005) 388-400.
• [119]Adolph, C. [COMPASS Collaboration] (2017). Resonance production and S-wave in π^-+p→π^- π^- π^++precoil at 190 GeV/c. Phys.Rev. D95 (3) 032004.
• [120] Bing, C., Wei, K.W. and Zhang, A. (2013). X(1870) and η_2 (1870): Which can be assigned as a hybrid state? Adv. High Energy Phys. 2013, 217858.
• [121] Anisovich, A.V. et al. [Crystal Barrel Collaboration] (2000). Three I=0,J^PC=2^(-+) mesons Phys. Lett. B 477, 19.
• [122] Barberis, D. et al. [WA102 Collaboration] (2000). A Study of the ηπ^+ π^-channel produced in central pp interactions at 450 GeV/c. Phys.Lett. B471, 435.
• [123] Chen, Y.Q. and Li, X.Q. (2004). A comprehensive four-quark interpretation of D_s (2317),D_s (2457) and D_s (2632). Phys.Rev.Lett. 93 232001.
• [124] Cheng, H.Y. and Hou, W.S. (2003). B decays as spectroscope for charmed four quark states, Phys. Lett. B566, 193.
• [125] Browder, T.E., Pakvasa, S. and Petrov, A.A. (2004). Comment on the new D_s^((*)+) π^0 resonances, Phys. Lett.B578, 365.
• [126] B. Aubert et al. [BaBar collaboration] (2003). Observation of a narrow meson decaying to D_s^+ π^0 at a mass of 2.32 GeV/c^2. Phys. Rev. Lett. 90, 242001.
• [127] Krokovny, P. et al., [Belle collaboration] (2003). Observation of the D_sJ (2317) and D_sJ (2457) in B decays. Phys. Rev. Lett. 91, 262002.
• [128] Besson, D. et al. [CLEO collaboration] (2003). Observation of a narrow resonance of mass 2.46GeV/c^2 decaying to D_s^(*+) π^0 and confirmation of the D_SJ^* (2317) state, Phys. Rev. D68, 032002 [Erratum ibid. D 75 (2007) 119908].
• [129] Vaandering, E.W. (2004). Charmed hadron spectroscopy from FOCUS in: QCD and high energy hadronic interactions. Proceedings, 39th Rencontres de Moriond, La Thuile, Italy, March 28-April 2, pp. 127–132. arXiv:hep-ex/0406044.
• [130] Yang, G. and Ping, J. The structure of pentaquarks Ω_c^0 in the chiral quark model. Mar 26, 2017. 8 pp. arXiv:1703.08845 [hep-ph].
• [131] Huang, H., Ping, J. and Wang, F. Investigating the excited Ω_c^0 states through Ξ_c K and Ξ_c^' cK decay channels. Apr 5, 2017. 6 pp. arXiv:1704.01421 [hep-ph].
• [132] Aaij, R.et al. [LHCb Collaboration] (2017). Observation of five new narrow Ω_c^0 states decaying to Ξ_c^+ K. Phys.Rev.Lett. 118 (18) 182001.
• [133] Govaerts, J., Viron, F.D., Gusbin, D. and Weyers, J. (1984). QCD sum rules and hybrid mesons. Nucl.Phys. B248, 1-18.
• [134] Bhardwaj, V. et al. [Belle Collaboration] (2013). Evidence of a new narrow resonance decaying to χ_1c γ in 〖B→χ〗_c1 γK. Phys.Rev.Lett. 111 (3) 032001.
• [135] Ablikim, M. et al. [BESIII Collaboration] (2015). Observation of the ψ(1^3 D^2) state in e^+ e^-→π^+ π^- γχ_1c at BESIII. Phys.Rev.Lett. 115 (1) 011803.
• [136] Antoniazzi, L. et al. [E705 Collaboration] (1994). Search for hidden charm resonance states decaying into J /ψ or ψ' plus pions. Phys.Rev. D50, 4258-4264.
• [137] Li, B.A. (2005). Is X(3872) a possible candidate of hybrid meson. Phys.Lett. B605, 306-310.
• [138] Voloshin, M.B. (2004). Heavy quark spin selection rule and the properties of the X(3872). Phys.Lett. B604, 69-73.
• [139] Burns, T.J., Piccinini, F., Polosa, A.D. and Sabelli, C. (2010). The 2^(-+) assignment for the X(3872). Phys.Rev. D82, 074003.
• [140] Maiani, L., Piccinini, F., Polosa, A. D. and Riquer, V. (2005). Diquark-antidiquarks with hidden or open charm and the nature of X(3872). Phys. Rev. D71, 014028.
• [141] Aubert, B. [BaBar Collaboration] (2004). Observation of the decay B→J/ψηK and search for X(3872)→J/ψη. Phys.Rev.Lett. 93, 041801.
• [142] Abazov, V.M. et al. [D0 Collaboration] Observation and properties of the X(3872) decaying to J/ψπ^+ π^- in p ̅p collisions at √s=1.96TeV, Phys. Rev. Lett. 93 (2004) 162002.
• [143] Ikeda, Y. [HAL QCD Collaboration] (2017). The Tetraquark candidate Z_c (39〖00)〗^ from Dynamical Lattice QCD Simulations. arXiv:1706.07300 [hep-lat].
• [144] Ablikim, M. et al. [BESIII Collaboration] (2015). Observation of Z_c (39〖00)〗^0 in e^+ e^-→π^0 π^0 J/ψ. Phys.Rev.Lett. 115 (11) 112003.
• [145] Dobbs, S. et al. [CLEO Collaboration] (2007). Measurement of absolute hadronic branching fractions of D mesons and e^+ e^-→ DD cross-sections at the ψ(3770). Phys.Rev. D76, 112001.
• [146] Hogaasen,H., Kou, E., Richard, J.M. and Sorba, P. (2014). Isovector and hidden-beauty partners of the X(3872). Phys. Lett. B 732, 97.
• [147] Karliner, M., Rosner, J.L. (2015). New exotic meson and baryon resonances from doubly-heavy hadronic molecules, Phys. Rev. Lett. 115 (12) 122001.
• [148] Uehara, S. et al., [Belle Collaboration] (2010). Observation of a charmonium-like enhancement in the γγ→ωJ/ψ process, Phys. Rev. Lett. 104, 092001.
• [149] Lees, J.P. et al. [BaBar Collaboration] (2012). Study of X(3915)→J/ψω in two-photon collisions, Phys. Rev. D86, 072002.
• [150] Liao, X. and Manke, T. (2002). Excited charmonium spectrum from anisotropic lattices, CU-TP-1063, arXiv:hep-lat/0210030v2.
• [151] Close, F.E. and Godfrey, S. (2003). Charmonium hybrid production in exclusive B meson decays. Phys.Lett. B574, 210-216.
• [152] Branz, T., Gutsche, T. and Lyubovitskij, V.E. (2009). Hadronic molecule structure of the Y(3940) and Y(4140). Phys.Rev. D80, 054019.
• [153]Pakhlov, P. [Belle Collaboration] (2008). Production of new charmoniumlike states in e^+ e^-→J/ψD^((*)) ▁D^((*))at √s≈10.6 GeV. Phys.Rev.Lett. 100, 202001.
• [154] Aubert, B. et al., [BaBar Collaboration] (2008). Observation of Y(3940) →J/ψω in B→J/ψωK at BABAR. Phys. Rev. Lett. 101, 082001.
• [155] Wang, Z.G. (2016). Tetraquark state candidates: Y(4260),Y(4360),Y(4660) and Z_c (4020/4025) Eur.Phys. J. C76 (7) 387.
• [156] Yuan, C.Z. [BESIII Collaboration] (2015). Study of the XYZ states at the BESIII Front.Phys. (Beijing) 10 (6) 101401.
• [157] Ablikim, M. et al. [BESIII Collaboration] (2014). Observation of e^+ e^-→π^0 π^0 h_c and a neutral charmoniumlike structure Z_c (402〖0)〗^0. Phys. Rev. Lett. 113, 212002.
• [158] Oncala, R. and Soto, J. (2017). Heavy quarkonium hybrids: Spectrum, decay and mixing. Phys.Rev. D96 (1) 014004.
• [159] Chen, X. et al. (2016). Calculation of mass of Y(4140) by introducing mixed molecule state in quark model. Nucl.Phys. B909, 243-259.
• [160] Dağ, H. and A. Türkan. (2017). Investigating the structure of X(4140) in QCD. EPJ Web Conf. 137, 06007.
• [161] Agaev, S.S. Azizi, K. and Sundu, H. (2017). Exploring the resonances X(4140) and X(4274) through their decay channels. Phys.Rev. D95, (11) 114003.
• [162] Wang, Z.G. (2016). Reanalysis of X(4140) as axial-vector tetraquark state with QCD sum rules. Eur.Phys.J. C76 (12) 657.
• [163] Aaltonen, T. et al., [CDF Collaboration] (2009). Evidence for a narrow near-threshold structure in the J/ψϕ mass spectrum in B^+→J/ψϕK^+ decays, Phys. Rev. Lett. 102, 242002.
• [164] Chatrchyan, S. et al., [CMS Collaboration] (2014). Observation of a peaking structure in the J/ψϕ mass spectrum from B^±→J/ψϕK^± decays, Phys. Lett. B734, 261–281.
• [165] Abazov, V.M. [D0 Collaboration] (2014). Search for the X(4140) state in B^+→J/ψϕK^+decays with the D0 Detector. Phys.Rev. D89 (1) 012004.
• [166] Prencipe, E. [BABAR Collaboration] (2015). Search for exotics in the rare decay B→J/ψKKK at BABAR. EPJ Web Conf. 95, 05012.
• [167] Chen, Y., Chiu, W.F., Gong, M., Gui, L.C. and Liu, Z. (2016). Exotic vector charmonium and its leptonic decay width. Chin. Phys. C40 (8) 081002.
• [168] Wang, Z.G. (2017). Analysis of the Y(4220) and Y(4390) as molecular states with QCD sum rules. Chin.Phys. C41 (8) 083103.
• [169] Feng, X.N., Gao, X.Y. and Shen, C.P. (2015). Combined fit to BESIII data on e^+ e^-→h_c π^+ π^- and χ_c0 ω. Int.J.Mod.Phys. A30 (24) 1550142.
• [170] Wang, X.L. et al. [Belle Collaboration] (2015). Measurement of e^+ e^-→π^+ π^- ψ(2S) via initial state radiation at Belle, Phys. Rev. D 91, 112007.
• [171] Ablikim, M. et al. [BESIII Collaboration] (2015). Study of e^+ e^-→ωχ_cJ at center-of-mass energies from 4.21 to 4.42 GeV, Phys. Rev. Lett. 114, 092003.
• [172] Zhu, S.L. (2008). New hadron states. Int.J.Mod.Phys. E17, 283-322.
• [173] Qiao, C.F. (2006). One explanation for the exotic state Y(4260). Phys.Lett. B639, 263.
• [174] Lees, J.P. [BaBar Collaboration] (2012). Study of the reaction e^+ e^-→J/ψπ^+ π^- via initial-state radiation at BaBar. Phys.Rev. D86, 051102.
• [175] He, Q. [CLEO Collaboration] (2006). Confirmation of the Y(4260) resonance production in ISR. Phys.Rev. D74, 091104.
• [176] Wang, M.Z. et al. [BELLE Collaboration] (2005). Study of the baryon-antibaryon low-mass enhancements in charmless three-body baryonic B decays. Phys. Lett. B617, 141.
• [177] Lees, J.P. et al. [BaBar Collaboration] (2014). Study of the reaction e^+ e^-→ψ(2S) π^- π^- via initial-state radiation at BaBar, Phys. Rev. D89 (11) 111103.
• [178] Wang X.L. et al., [Belle Collaboration] (2007). Observation of two resonant structures in e^+ e^-→π^+ π^- ψ(2S)via initial state radiation at Belle, Phys. Rev. Lett. 99, 142002.
• [179] He, J. (2016). DΣ_c^* and D^* Σ_c^ interactions and the LHCb hidden-charmed pentaquarks. Phys.Lett. B753, 547.
• [180] Azizi, K. Sarac, Y. and Sundu, H. Hidden bottom pentaquark states with spin 3/2 and 5/2. arXiv:1707.01248v1 [hep-ph].
• [181] Deng, C., Ping, J., Huang, H. and Wang, F. (2015). Systematic study of Z_c^+ family from a multiquark color flux-tube model, Phys. Rev. D92 (3) 034027.
• [182] Chilikin, K. [Belle Collaboration] (2013). Experimental constraints on the spin and parity of the Z(4430)^+. Phys.Rev. D88, (7) 074026.
• [183] Wang, Z.G. (2017). Scalar tetraquark state candidates: X(3915),X(4500) and X(4700). Eur.Phys.J. C77 (2) 78.
• [184] Aaij, R. [LHCb Collaboration] (2017). Amplitude analysis of B^+→J/ψϕK^+ decays. Phys.Rev. D95, (1) 012002.
• [185] Oncala, R. and Soto, J. (2017). Heavy hybrids: Decay to and mixing with heavy quarkonium. EPJ Web Conf. 137, 06025.
• [186] Wang, Z.G. and Zhang, X.H. (2010). Analysis of Y(4660) and related bound states with QCD sum rules. Commun. Theor. Phys. 54, 323.
• [187] Aubert, B. et al. [BaBar Collaboration] (2007). Evidence of a broad structure at an invariant mass of 4.32 GeV/c^2 in the reaction〖 e〗^+ e^-→π^+ π^- ψ(2S) measured at BaBar. Phys. Rev. Lett. 98, 212001.
• [188] Albaladejo, M., Nieves, J., Oset, E., Sun, Z.F. and Liu, X. (2016). X(5568) be described as a B_s π,BK ̅ resonant state? Phys.Lett. B757, 515-519.
• [189] Agaev, S.S., Azizi, K. and Sundu, H. (2016). Mass and decay constant of the newly observed exotic X(5568) state, Phys. Rev. D93 (7) 074024.
• [190] Zhang, J.R., Zou, J.L. and Wu, J.Y. 0^+ tetraquark states from improved QCD sum rules: Delving into X(5568).May 10, 2017. 14 pp. e-Print: arXiv:1705.03741 [hep-ph].
• [191] Krokovny, P. [Belle Collaboration] (2013). First observation of the Z_b (10610) in a Dalitz analysis of Υ(10860)→Υ(nS)π^0 π^0. Phys.Rev. D88, (5) 052016.
• [192] Wang, Z.G. and Huang, T. (2014). The Z_b (10610) and Z_b (10650) as axial-vector tetraquark states in the QCD sum rules. Nucl.Phys. A930, 63-85.
• [193] Guo, F.K., Hidalgo-Duque, C., Nieves, J., Ozpineci, A. and Valderrama, M.P. (2015). Hidden charm and bottom molecular states. Hyperfine Interact. 234 (1-3) 125-132.
• [194] Bondar et al. [Belle Collaboration] (2012). Observation of two charged bottomonium-like resonances in Y(5S) decays. Phys. Rev. Lett. 108, 122001.