Z _c (3900)

Z _c (3900) is a hadron . It has four valence quarks . It is believed to be either a tetraquark or a hadron molecule . It is about four times as heavy as a proton and has a lifespan of about 10 ⁻²³ seconds. The particle was discovered in 2013 by researchers from the Belle experiment at KEK and BES III at the Beijing Electron Positron Collider .

Individual evidence

↑ C. Patrignani et al . (2016) and 2017 update: Particle listings - X (3900) (PDF; 61 kB)
↑ ZQ Liu et al. (Belle Collaboration): "Study of e ⁺ e ^- → π ⁺ π ^- J / ψ and Observation of a Charged Charmoniumlike State at Belle"; Phys. Rev. Lett. 110, 252002 (2013) [7 pages] ( doi: 10.1103 / PhysRevLett.110.252002 ).
↑ M. Ablikim et al. (BESIII Collaboration): “Observation of a Charged Charmoniumlike Structure in e ⁺ e ^- → π ⁺ π ^- J / ψ at √s = 4.26 GeV”; Phys. Rev. Lett. 110, 252001 (2013) [7 pages] ( doi: 10.1103 / PhysRevLett.110.252001 ).
↑ Devin Powell: Quark quartet opens fresh vista on matter . In: Nature . 498, June 18, 2013, pp. 280-281. doi : 10.1038 / 498280a . Retrieved June 19, 2013.
↑ Eric Swanson: Viewpoint: New Particle Hints at Four-Quark Matter . In: Physics . 6, June 17, 2013, p. 69. doi : 10.1103 / Physics.6.69 . Retrieved June 19, 2013.