[1] -K., Choi, et al. (
Belle Collaboration) “Observation of a Narrow Charmoniumlike State in Exclusive B±→K±π+π-J/ψ Decays”,
Phys. Rev. Lett. 91 (26) (2003) 262001. doi.org/10.1103/PhysRevLett.91.262001
[4] Burns, T.J., Swanson, E.S., “Interpreting the X(5568)”, Phys. Lett. B,760 (2016), 627-633, doi.org/10.1016/j.physletb.2016.07.049; Chen, X., Pinga, J., “Is the exotic X(5568) a bound state?” Eur. Phys. J. C (2016) 76:351, doi.org/10.1140/epjc/s10052-016-4210-x
[5] Liu, Y., et al., “Pentaquark and Tetraquark states” arXiv:1903.11976v2 [hep-ph] 2019. https://doi.org/10.48550/arXiv.1903.11976
[6] Hellmann, H., “A new approximation method in the problem of many electrons, J. Chem Phys.
3 (1935) 61.
org/10.1063/1.1749559
[7] Dienykhan, , Efimov, G., GanboldS, G., Nedelko, N., “Oscillator Representation in Quantum Physics”, first ed., Springer-Verlag, DE, (1995).
[8] Rosenfelder, R., “Path Integrals in Quantum Physics”, arXiv:1209.1315v2 [nucl-th], (2012).
[9] Feynman, P., Hibbs, A.R., “Quantum Mechanics and Path Integrals”, Dover Publications Inc, (2010)
[10] Peskin, E.,
Schroeder, D. V., “An Introduction To Quantum Field Theory” CRC Press; 1st edition (2019)
[11] Kelley, J., Leventhal, J., “Ladder Operators for the Harmonic Oscillator:Problems in classical and quantum mechanics”, first ed., Publishing Springer- Verlag, DE, (2017)
[12] Omugbe, E., et al, “Approximate mass spectra and root mean square radii of quarkonia using Cornell potential plus spin-spin interactions”, Nuclear Physics, A1034 (2023) doi.org/10.1016/j.nuclphysa.2023.122653
[13] Zyla, P.A. et al., Particle Data Group, Prog. Theor. Exp. Phys. 083C0, (2020).
[14] Kumar Rai A., Rathaud, D. P., “The mass spectra and decay properties of dimesonic states, using the Hellmann potential”, Eur. Phys. J. C (2015) 75:462. doi.org/10.1140/epjc/s10052-015-3695-z
[15] Mahajan, N., “Y(4140): Possible options”, Phys.Lett. B6 79 (2009) 228-230, doi.org/10.1016/j.physletb.2009.07.043