Gauge invariance and the electromagnetic current of composite pions

Technical Report · Wed Sep 01 04:00:00 EDT 1993

DOI:https://doi.org/10.2172/10184895· OSTI ID:10184895

Frank, M R ^[1]; Tandy, P C ^[2]

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1. Hampton Univ., VA (United States). Dept. of Physics
2. Kent State Univ., OH (United States). Dept. of Physics

The Global Color-symmetry Model of QCD is extended to deal with a background electromagnetic field and the associated conserved current is identified for composite {bar q}q pion modes of the model. Although the analysis is limited to tree level in the bilocal fields that bosonize the model, the identified photon-pion vertex produces the charge form factor associated with ladder Bethe-Salpeter pion amplitudes. A Ward-Takahashi identity for this vertex is derived in terms of the effective inverse propagator for the equivalent local pion field and the intrinsic ladder Bethe-Salpeter amplitudes. This identity is then used to illustrate gauge invariance by showing that identical vertex information is produced from the gauge change of the free action once proper account is taken of the gauge transformation properties of the bilocal pion fields. Comments are made on the location of the vector dominance mechanism in this treatment.

• Research Organization: Southeastern Universities Research Association, Inc., Newport News, VA (United States). Continuous Electron Beam Accelerator Facility
• Sponsoring Organization: USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 10184895
• Report Number(s): DOE/ER/40150--240; HUPhy--01-93; CEBAF-TH--93-05; ON: DE93040869; IN: KSUCNR-004-93; CNN: Grant HRD91-54080; PHY91-13117
• Country of Publication: United States
• Language: English

Related Subjects

662120
662240
662420
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BETHE-SALPETER EQUATION
COLOR MODEL
ELECTROMAGNETIC FIELDS
FORM FACTORS
GAUGE INVARIANCE
MODELS FOR STRONG INTERACTIONS
PIONS
PROPERTIES OF MESONS AND MESON RESONANCES
QUANTUM CHROMODYNAMICS
QUARK MODEL
SYMMETRY
CONSERVATION LAWS
CURRENTS AND THEIR PROPERTIES
VECTOR MESONS