nLab exotic meson

Contents

Context

Fields and quanta

fields and particles in particle physics

and in the 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

hadrons (bound states of the above quarks)

solitons

in grand unified theory

minimally extended supersymmetric standard model

superpartners

bosinos:

sfermions:

dark matter candidates

Exotica

auxiliary fields

Contents

Idea

An exotic meson is a hadron of baryon number zero which however, in contrast to actual mesons, has Wigner classification given by an isospin and Lorentz-spin group representation which is not a direct summand of a tensor product of representations of that of a quark-pair.

Hence the existence of exotic mesons is not readily explained by the QCD-based constituent quark model of quantum hadrodynamics, where mesons are bound states of two quarks (and baryons of three).

Some exotic mesons may possibly be interpreted as tetraquarks

Examples

References

Review:

  • Th. Gutsche, Exotic Mesons (pdf)

  • Luciano Maiani, Alessandro Pilloni, GGI Lectures on Exotic Hadrons [arXiv:2207.05141

See also

Last revised on July 13, 2022 at 06:50:24. See the history of this page for a list of all contributions to it.