nLab
XYZ particle

Contents

Context

Fields and quanta

field (physics)

standard model of particle physics

force field gauge bosons

scalar bosons

matter field fermions (spinors, Dirac fields)

flavors of fundamental fermions in the
standard model of particle physics:
generation of fermions1st generation2nd generation3d generation
quarks (qq)
up-typeup quark (uu)charm quark (cc)top quark (tt)
down-typedown quark (dd)strange quark (ss)bottom quark (bb)
leptons
chargedelectronmuontauon
neutralelectron neutrinomuon neutrinotau neutrino
bound states:
mesonslight mesons:
pion (udu d)
ρ-meson (udu d)
ω-meson (udu d)
f1-meson
a1-meson
strange-mesons:
ϕ-meson (ss¯s \bar s),
kaon, K*-meson (usu s, dsd s)
eta-meson (uu+dd+ssu u + d d + s s)

charmed heavy mesons:
D-meson (uc u c, dcd c, scs c)
J/ψ-meson (cc¯c \bar c)
bottom heavy mesons:
B-meson (qbq b)
ϒ-meson (bb¯b \bar b)
baryonsnucleons:
proton (uud)(u u d)
neutron (udd)(u d d)

(also: antiparticles)

effective particles

hadron (bound states of the above quarks)

solitons

minimally extended supersymmetric standard model

superpartners

bosinos:

sfermions:

dark matter candidates

Exotica

auxiliary fields

Contents

Idea

XYZ particles are charmonium-like exotic mesons which are increasingly being observed in experiment (typically in B-meson-experiments such as Belle, LHCb, , BaBar), but whch are hard to interpret as bound states in the traditional quark model (in theoretical physics) of quantum chromodynamics.

References

Review:

  • Stephen Godfrey and Stephen L. Olsen, The Exotic XYZ Charmonium-Like Mesons, Annual Review of Nuclear and Particle Science Vol. 58:51-73 (Volume publication date 23 November 2008) (arXiv:10.1146/annurev.nucl.58.110707.171145)

  • Xiang Liu, An overview of XYZ new particles, Chin. Sci. Bull. 59, 3815-3830 (2014) (arXiv:1312.7408)

  • Stephen Lars Olsen, The XYZ mesons: what they aren’t, EPJ Web of Conferences 202, 01003 (2019) (doi:10.1051/epjconf/201920201003)

  • Nora Brambilla, Simon Eidelman, Christoph Hanhart, Alexey Nefediev, Cheng-Ping Shen, Christopher E. Thomas, Antonio Vairo, Chang-Zheng Yuan, The XYZ states: experimental and theoretical status and perspectives, Physics Reports 2020 (arXiv:1907.07583)

See also

Last revised on May 15, 2020 at 02:53:24. See the history of this page for a list of all contributions to it.