Electromagnetic couplings of elementary vector particles

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.77.014009· OSTI ID:21035692

Napsuciale, M ^[1]; Rodriguez, S ^[2]; Delgado-Acosta, E G ^[1]; Kirchbach, M ^[3]

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1. Instituto de Fisica, Universidad de Guanajuato, Lomas del Bosque 103, Fraccionamiento Lomas del Campestre, 37150, Leon, Guanajuato (Mexico)
2. Facultad de Ciencias Fisico Matematicas, Universidad Autonoma de Coahuila, Edificio 'D', Unidad Camporredondo, CP 25280, Saltillo, Coahuila (Mexico)
3. Instituto de Fisica, Universidad Autonoma de San Luis Potosi, Av. Manuel Nava 6, San Luis Potosi, 78290, S.L.P. (Mexico)

On the basis of the three fundamental principles of (i) Poincare symmetry of space-time, (ii) electromagnetic gauge symmetry, and (iii) unitarity, we construct an universal Lagrangian for the electromagnetic interactions of elementary vector particles, i.e., massive spin-1 particles transforming in the ((1/2),(1/2)) representation space of the homogeneous Lorentz group. We make the point that the first two symmetries alone do not fix the electromagnetic couplings uniquely but solely prescribe a general Lagrangian depending on two free parameters, here denoted by {xi} and g. The first one defines the electric-dipole and the magnetic-quadrupole moments of the vector particle, while the second determines its magnetic-dipole and electric-quadrupole moments. In order to fix the parameters one needs an additional physical input suited for the implementation of the third principle. As such, one chooses Compton scattering off a vector target and requires the cross section to respect the unitarity bounds in the high-energy limit. As a result, we obtain the universal g=2 and {xi}=0 values which completely characterize the electromagnetic couplings of the considered elementary vector field at tree level. The nature of this vector particle, Abelian versus non-Abelian, does not affect this structure. Merely, a partition of the g=2 value into non-Abelian, g{sub na}, and Abelian, g{sub a}=2-g{sub na}, contributions occurs for non-Abelian fields with the size of g{sub na} being determined by the specific non-Abelian group appearing in the theory of interest, be it the standard model or any other theory.

• OSTI ID: 21035692
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 1 Vol. 77; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COMPTON EFFECT
CROSS SECTIONS
ELECTRIC DIPOLES
ELECTROMAGNETIC INTERACTIONS
GAUGE INVARIANCE
LAGRANGIAN FUNCTION
LORENTZ GROUPS
MAGNETIC DIPOLES
QUADRUPOLE MOMENTS
SPACE-TIME
SPIN
STANDARD MODEL
SYMMETRY
UNITARITY
VECTOR FIELDS