The X(3872) is an exotic meson candidate with a mass of 3871.68 MeV/c which does not fit into the quark model. It was first discovered in 2003 by the Belle experiment in Japan and later confirmed by several other experimental collaborations. Several theories have been proposed for its nature, such as a mesonic molecule or a diquark-antidiquark pair (tetraquark).
The quantum numbers of X(3872) have been determined by the LHCb experiment at CERN in March 2013. The values for J are 1. The first evidence of X(3872) production in the quark–gluon plasma have been reported by the CMS experiment at CERN in January 2022.
See also
Notes
- Particle Data Group Live listings
- Choi, S.-K.; et al. (Belle Collaboration) (2003). "Observation of a Narrow Charmoniumlike State in Exclusive B±→K±π+π-J/ψ Decays". Physical Review Letters. 91 (26): 262001. arXiv:hep-ex/0308029. Bibcode:2003PhRvL..91z2001C. doi:10.1103/PhysRevLett.91.262001. PMID 14754041. S2CID 1017547.
- Swanson, E. S. (2006). "The new heavy mesons: A status report". Physics Reports. 429 (5): 243–305. arXiv:hep-ph/0601110. Bibcode:2006PhR...429..243S. doi:10.1016/j.physrep.2006.04.003. S2CID 54704359.
- Aaij, R.; et al. (LHCb collaboration) (2013). "Determination of the X(3872) meson quantum numbers". Physical Review Letters. 110 (22): 222001. arXiv:1302.6269. Bibcode:2013PhRvL.110v2001A. doi:10.1103/PhysRevLett.110.222001. PMID 23767712.
- Sirunyan, A. M.; et al. (CMS collaboration) (2022). "Evidence for X(3872) in Pb-Pb Collisions and Studies of its Prompt Production at 5.02 TeV". Physical Review Letters. 128 (3): 032001. arXiv:2102.13048. doi:10.1103/PhysRevLett.128.032001. PMID 35119878.
References
- David Harris (13 April 2008). "The charming case of X(3872)". Symmetry Magazine. Retrieved 2009-12-17.
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