Z(4430) is a mesonic resonance discovered by the Belle experiment.[1][2] It has a mass of 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
c

c

d

u
,[3] making it a tetraquark candidate. It has the spin-parity quantum numbers JP = 1+.

Z(4430)
ClassificationExotic meson
Composition
c

c

d

u

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]

See also

edit

References

edit
  1. ^ Choi, S.-K.; Belle Collaboration; et al. (2008). "Observation of a resonance-like structure in the
    π±
    Ψ mass distribution in exclusive B→K
    π±
    Ψ decays". Physical Review Letters. 100 (14): 142001. arXiv:0708.1790. Bibcode:2008PhRvL.100n2001C. doi:10.1103/PhysRevLett.100.142001. PMID 18518023. S2CID 119138620.
  2. ^ "Belle Discovers a New Type of Meson" (Press release). KEK. 2007. Archived from the original on 2009-01-22. Retrieved 2009-06-20.
  3. ^ a b LHCb collaboration (2014). "Observation of the resonant character of the Z(4430)− state". Physical Review Letters. 112 (22): 222002. arXiv:1404.1903. Bibcode:2014PhRvL.112v2002A. doi:10.1103/PhysRevLett.112.222002. PMID 24949760. S2CID 904429.
  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.
edit