Photon Mass Generation Research Articles

English

A phenomenological model is presented here arguing that photon mass is an induced effect rendered in the form of vacuum potential arising from vacuum natural modes. An elementary vacuum potential is defined as a function of vacuum zero-point fields, which yields an expression for effective photon mass generation. A Lagrangian is constructed for this model which incorporates photons with effective mass in vacuo. It is suggested that photons may acquire or present an effective mass while interactions with vacuum or other fields but they do not have an intrinsic rest mass. The photon mass emerges as a dynamical variable which depends on the coupling strength of electromagnetic fields to the vacuum natural modes and on the value of vector potential. Key words: Photon mass, Maxwell-Proca equations, vacuum potentials, Higgs potential.

COUPLING ELECTROMAGNETISM TO GLOBAL CHARGE

It is shown that an alternative to the standard scalar quantum electrodynamics (QED) is possible. In this new version, there is only global gauge invariance as far as the charged scalar fields are concerned, although local gauge invariance is kept for the electromagnetic field. The electromagnetic coupling has the form jμ(Aμ +∂μB) where B is an auxiliary field and the current jμ is Aμ independent, so that no "sea gull terms" are introduced. As a consequence of the absence of sea gulls, it is seen that no Klein paradox appears in the presence of a strong square well potential. In a model of this kind, spontaneous breaking of symmetry does not lead to photon mass generation, instead the Goldstone boson becomes a massless source for the electromagnetic field. When spontaneous symmetry breaking takes place infrared questions concerning the theory and generalizations to global vector QED are discussed. In this framework, Q-Balls and other nontopological solitons that owe their existence to a global U(1) symmetry can be coupled to electromagnetism and could represent multiply charged particles now in search in the large hadron collider (LHC). Furthermore, we give an example where an "Emergent" Global Scalar QED can appear from an axion–photon system in an external magnetic field. Finally, formulations of Global Scalar QED that allow perturbative expansions without sea gulls are developed.

ABELIAN MAGNETIC MONOPOLES AND TOPOLOGICALLY MASSIVE VECTOR BOSONS IN SCALAR-TENSOR GRAVITY WITH TORSION POTENTIAL

A Lagrangian formulation describing the electromagnetic interaction — mediated by topologically massive vector bosons — between charged, spin-½ fermions with an Abelian magnetic monopole in a curved space–time with nonminimal coupling and torsion potential is presented. The covariant field equations are obtained. The issue of coexistence of massive photons and magnetic monopoles is addressed in the present framework. It is found that despite the topological nature of photon mass generation in curved space–time with isotropic dilaton field, the classical field theory describing the nonrelativistic electromagnetic interaction between a point-like electric charge and magnetic monopole is inconsistent.

Photon mass generation during inflation: de Sitterinvariant case

We calculate the one-loop vacuum polarization tensor of scalarelectrodynamics in a locally de Sitter space-time, endowed witha nearly minimally coupled, light scalar field. We show that thephoton dynamics is well approximated by a (local) ProcaLagrangean. Since the photon mass can be much larger than theHubble parameter, the photons may propagate slowly duringinflation. Finally, we briefly discuss magnetic field generationon cosmological scales, and point out that while the spectrumof the magnetic field is identical to that obtained from themassless scalar, Bℓ≃B0/ℓ, the amplitude B0may be significantly enhanced, implying that the seed fieldbound for the galactic dynamo can be easily met.

Volume-preserving diffeomorphisms' versus local gauge symmetry

We present a new form of quantum electrodynamics where the photons are composites made out of zero-dimensional scalar “primitives”. The role of the local gauge symmetry is taken over by an infinite-dimensional global Noether symmetry - the group of volume-preserving (symplectic) diffeomorphisms of the target space of the scalar primitives. A similar construction can be carried out for higher antisymmetric tensor gauge theories. Solutions of the Maxwell equations are automatically solutions of the new system. However, the latter possesses additional non-Maxwell solutions which display some interesting new effects: (a) a magneto-hydrodynamical analogy, (b) absence of the electromagnetic self-energy for electron plane wave solutions, and (c) gauge invariant photon mass generation, where the magnitude of the generated mass is arbitrary.

Chiral anomaly and unambiguous terms of exact scale behavior

We perform new explicit and regularization-independent calculations of AV amplitude in QED1+1 and AVV amplitude in QED1+3 respectively to reinvestigate the anomaly problem. A kind of finite and unambiguous terms of exact scale behavior (in momentum space) is found to be responsible for the anomalies both in QED1+1 and QED1+3. They come from logarithmically divergent momentum integrals in contrast with the usual knowledge for triangle anomaly in QED1+3. In QED1+1, this term is also responsible for photon mass generation. Some implications and possible relations with other aspects of anomaly are discussed.

INDUCED B∧F TERM AND PHOTON MASS GENERATION IN 3+1 DIMENSIONS

Analyzing a (3+1)-dimensional model with four-fermi interactions, we show that topological B∧F terms (both Abelian and non-Abelian) can be induced radiatively by massive fermions at the one-loop level. It is further pointed out that a mechanism of photon (or non-Abelian gauge field) mass generation distinct from the usual Higgs mechanism, through the B∧F term, is also implemented in the long distance effective action of this model, provided a gap equation is satisfied.

Photon polarization tensor and gauge dependence in three-dimensional quantum electrodynamics.

We calculate the three-dimensional QED (${\mathrm{QED}}_{3}$) photon polarization tensor using dressed fermion propagators and a fermion-photon vertex that satisfies the Ward-Takahashi identity. Irrespective of the structural details of the transverse part of the fermion-photon vertex the photon remains massless; i.e., there is no photon mass generation in the manner of the Schwinger mechanism. Our calculation suggests that ${\mathrm{QED}}_{3}$ is confining when the polarization tensor is calculated using a dressed fermion propagator and fermion-photon vertex. The gauge parameter dependence of the fermion propagator, fermionphoton vertex, and photon polarization tensor is discussed in connection with the Landau-Khalatnikov gauge transformation laws.

Pion condensates. Multiple photon mass generation in presence of heavy ions

It is shown that the charged pion-photon coupling, in the region between two heavy nuclei while colliding, gives rise to a photon mass. Independently of this, when there is a neutral pion condensation (also in the region between the heavy nuclei) as well, a mass arises from a Chern-Simons type term. However, when both these effects are considered together, photons having a multiple mass spectrum are generated. It is thus suggestive that the decay of the “heavy” photons into e +e − could provide an explanation of the anomalous multiple e +e − MeV peaks observed in heavy ion scattering.

Pion condensate. Photon mass generation in presence of heavy ions

It is shown that the pion-photon coupling, when there is a pion condensation, gives rise to a Chern-Simons type term. This leads to an anisotropic topological mass generation for the photon. The anisotropy is the result of two of the spatial dimensions treated differently than the third. The possibility that this phenomenon could take place during heavy-ion collisions is examined in an attempt to explain the anomalous observed MeV e +e − peaks.

Perturbative analysis of anomalous chiral QED.

We calculate the full Wess-Zumino terms for anomalous chiral QED at the fermion one-loop level in lattice perturbation theory, except the explicit form of order-$a$ terms, which can contribute in leading order in $a$ and $e$ by the integration of other fields. First we rewrite the result in terms of a local effective theory with the Wess-Zumino scalar in order to discuss gauge invariance, photon mass generation, renormalizability, and (effective) unitarity. Second we integrate this Wess-Zumino scalar and consider the resulting nonlocal theory to test a recent proposal for the quantization of anomalous gauge theory. We also present some one-loop calculations of the Wess-Zumino scalar integration to demonstrate how this integration recovers the original gauge invariance while producing a photon mass.