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ghost field

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

In gauge theory the configuration space/phase space is not in general a smooth space, but a smooth groupoid: the gauge transformations between gauge fields are the morphisms of this groupoid.

The infinitesimal approximation to this smooth groupoid is a Lie algebroid. The dg-algebra of functions on this is called the BRST complex of the gauge theory. It contains in degree-0 the (duals to) the gauge fields and in degree-1 the cotangents to the gauge transformations. These degree-1 elements that appear here alongside the physical fields in degree 0 are called ghost fields in the physics literature.

If there are higher gauge transformationsgauge-of-gauge transformations” then the BRST complex has generators in higher degree, too, the cotangents to these higher gauge transformations. These are then called ghost-of-ghost fields.

For more details and further pointers see at BRST complex and in particular at BV-BRST formalism.

Last revised on December 9, 2017 at 10:05:57. See the history of this page for a list of all contributions to it.