Z(4430)

Z(4430) is a mesonic resonance discovered by the Belle experiment.^[1][2] It has a mass of 7003443000000000000♠4430 MeV/c². The resonant nature of the peak has been confirmed by the LHCb experiment with a significance of at least 13.9 σ.^[3] The particle is charged and is thought to have a quark content of ccdu,^[3] making it a tetraquark candidate. It has the spin-parity quantum numbers J^P = 1⁺.

The particle joins the X(3872), Zc(3900) and Y(4140) as exotic hadron candidates observed by multiple experiments, although it is the first to be confirmed as a resonance.^[4][5]

References

1. ↑ Choi, S.-K.; Belle Collaboration; et al. (2007). "Observation of a resonance-like structure in the π±Ψ′ mass distribution in exclusive B→Kπ±Ψ′ decays". Physical Review Letters 100 (14). arXiv:0708.1790. Bibcode:2008PhRvL.100n2001C. doi:10.1103/PhysRevLett.100.142001. 
2. ↑ "Belle Discovers a New Type of Meson" (Press release). KEK. 2007. Retrieved 2009-06-20. 
3. 1 2 LHCb collaboration (2014). "Observation of the resonant character of the Z(4430)− state". arXiv:1404.1903v1. 
4. ↑ Cian O'Luanaigh (9 April 2014). "LHCb confirms existence of exotic hadrons". CERN. 
5. ↑ "Unambiguous observation of an exotic particle which cannot be classified within the traditional quark model". European Organization for Nuclear Research. 9 April 2014. 

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