A condition on the chiral symmetry breaking solution of the Dyson-Schwinger equation in three-dimensional QED

In three-dimensional QED, which is analyzed in the 1/$N$ expansion, we obtain a sufficient and necessary condition for a nontrivial solution of the Dyson-Schwinger equation to be chiral symmetry breaking solution. In the derivation, a normalization condition of the Goldstone bound state is used. It is showed that the existent analytical solutions satisfy this condition.Comment: 11 pages, Latex, no figures, accepted by Phys.Lett.

Breaking Discrete Symmetries in Broken Gauge Theories

We study the spontaneous breaking of discrete symmetries in theories with broken gauge symmetry. The intended application is to CP breaking in theories with gauged flavor symmetries, but the analysis described here is preliminary. We dispense with matter fields and take the gauge theory to be weakly coupled and broken spontaneously by unspecified, short-distance forces. We develop an effective-field-theory description of the resultant low energy theory, and ask whether this theory by itself can describe the subsequent breaking of discrete symmetries. We conclude that this can happen depending on the parameters of the effective theory, and that the intrinsic violation is naturally of order unity.Comment: 9 pages, 1 figure, corrected typos, added a referenc

Neutrinos and SU(3) Family Gauge Symmetry

We include the standard-model (SM) leptons in a recently proposed framework for the generation of quark mass ratios and Cabibbo-Kobayashi-Maskawa (CKM) mixing angles from an SU(3) family gauge interaction. The set of SM-singlet scalar fields describing the spontaneous breaking is the same as employed for the quark sector. The imposition at tree-level of the experimentally correct Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix, in the form of a tri-bi maximal structure, fixes several of the otherwise free parameters and renders the model predictive. The normal hierarchy among the neutrino masses emerges from this scheme.Comment: 9 pages, 3 tables; a comment added to clarify the effects of additional Yukawa operators; final version in PR

The Electroweak Chiral Lagrangian and CP-Violating Effects in Technicolor Theories

We estimate the CP-violating $WW\gamma$ and $WWZ$ anomalous form factors, arising from CP-violating interactions in extended technicolor theories, and discuss their future experimental detectability. The electric dipole moment of the $W$ boson is found to be as large as {\cal O}(10^{-21}) \; \mbox{e cm}. We connect the CP-odd $WW\gamma$ and $WWZ$ couplings to the corresponding CP-violating electroweak chiral lagrangian operators. The electric dipole moments of the neutron and the electron in technicolor theories are estimated to be as large as {\cal O}(10^{-26}) \; \mbox{e cm} and {\cal O}(10^{-29}) \; \mbox{e cm} respectively. We also suggest the potential to observe large CP-violating technicolor effects in the decay $t \rightarrow b + W^+$.Comment: 34 pages, YCTP-P9-94, LaTex. (minor changes in wording and notation, the figures are appended at the end as one postscript file

Fermion Masses and Mixing in Extended Technicolor Models

We study fermion masses and mixing angles, including the generation of a seesaw mechanism for the neutrinos, in extended technicolor (ETC) theories. We formulate an approach to these problems that relies on assigning right-handed $Q=-1/3$ quarks and charged leptons to ETC representations that are conjugates of those of the corresponding left-handed fermions. This leads to a natural suppression of these masses relative to the $Q=2/3$ quarks, as well as the generation of quark mixing angles, both long-standing challenges for ETC theories. Standard-model-singlet neutrinos are assigned to ETC representations that provide a similar suppression of neutrino Dirac masses, as well as the possibility of a realistic seesaw mechanism with no mass scale above the highest ETC scale of roughly $10^3$ TeV. A simple model based on the ETC group SU(5) is constructed and analyzed. This model leads to non-trivial, but not realistic mixing angles in the quark and lepton sectors. It can also produce sufficiently light neutrinos, although not simultaneously with a realistic quark spectrum. We discuss several aspects of the phenomenology of this class of models.Comment: 74 pages, revtex with embedded figure

Generalized BRST Quantization and Massive Vector Fields

A previously proposed generalized BRST quantization on inner product spaces for second class constraints is further developed through applications. This BRST method involves a conserved generalized BRST charge Q which is not nilpotent but which satisfies Q=\delta+\delta^{\dagger}, \delta^2=0, and by means of which physical states are obtained from the projection \delta|ph>=\delta^{\dagger}|ph>=0. A simple model is analyzed in detail from which some basic properties and necessary ingredients are extracted. The method is then applied to a massive vector field. An effective theory is derived which is close to the one of the Stueckelberg model. However, since the scalar field here is introduced in order to have inner product solutions, a massive Yang-Mills theory with polynomial interaction terms might be possible to construct.Comment: 19 pages,Latexfil

Fermionic effective action and the pahse estructure of non compact quantum electrodynamics in 2+1 dimensions

We study the phase diagram of non compact $QED_3$ using the microcanonical fermionic average method described elsewhere. We present evidence for a continuous phase transition line in the $\beta, N$ plane, extending down to arbitrarily small flavour number $N$.Comment: 12 pags + 1 table + 5 figs; Ref: DFTUZ 93.0

Infra-Red Finite Charge Propagation

The Coulomb gauge has a long history and many uses. It is especially useful in bound state applications. An important feature of this gauge is that the matter fields have an infra-red finite propagator in an on-shell renormalisation scheme. This is, however, only the case if the renormalisation point is chosen to be the static point on the mass shell, p = (m, 0, 0, 0). In this letter we show how to extend this key property of the Coulomb gauge to an arbitrary relativistic renormalisation point. This is achieved through the introduction of a new class of gauges of which the Coulomb gauge is a limiting case. A physical explanation for this result is given.Comment: 8 pages, plain TeX, to appear in Modern Physics Letters