Search results for "BRS"
showing 10 items of 38 documents
Unitarity, Becchi-Rouet-Stora-Tyutin symmetry, and Ward identities in orbifold gauge theories
2004
We discuss the use of BRST symmetry and the resulting Ward identities as consistency checks for orbifold gauge theories in an arbitrary number of dimensions. We demonstrate that both the usual orbifold symmetry breaking and the recently proposed Higgsless symmetry breaking are consistent with the nilpotency of the BRST transformation. The corresponding Ward identities for four-point functions of the theory engender relations among the coupling constants that are equivalent to the sum rules from tree level unitarity. We present the complete set of these sum rules also for inelastic scattering and discuss applications to six-dimensional models and to incomplete matter multiplets on orbifold f…
The pinch technique at two loops
1999
It is shown that the fundamental properties of gauge-independence, gauge-invariance, unitarity, and analyticity of the $S$-matrix lead to the unambiguous generalization of the pinch technique algorithm to two loops.
Local BRST cohomology in gauge theories
2000
The general solution of the anomaly consistency condition (Wess-Zumino equation) has been found recently for Yang-Mills gauge theory. The general form of the counterterms arising in the renormalization of gauge invariant operators (Kluberg-Stern and Zuber conjecture) and in gauge theories of the Yang-Mills type with non power counting renormalizable couplings has also been worked out in any number of spacetime dimensions. This Physics Report is devoted to reviewing in a self-contained manner these results and their proofs. This involves computing cohomology groups of the differential introduced by Becchi, Rouet, Stora and Tyutin, with the sources of the BRST variations of the fields ("antif…
Do metric independent classical actions lead to topological field theories?
1991
Abstract We investigate the quantum theory of non-abelian BF -systems (gauge theories with the classical metric independent action ∫ tr BF A ). The fact that due to a complicated (on-shell reducible) gauge structure the quantum action of these theories does not differ only by a BRST commutator from the classical action, and that moreover the BRST operator turns out to be metric dependent, renders the standard arguments for metric independence inapplicable. We establish the topological nature of these models and argue that in gauge theories the information on gauge invariance is contained entirely in the metric independent part of the BRST operator. We make some general remarks on the relati…
Gauge-invariant proper self-energies and vertices in gauge-theories with broken symmetry
1990
Using the pinch technique, we show how to recover, from the {ital S} matrix of a spontaneously broken non-Abelian gauge theory, proper self-energies and vertices which are fully gauge invariant when one or more momenta are off shell. Explicit calculations are carried out at the one-loop level for gauge-boson self-energies and fermion--gauge-boson vertices in a simple SU(2) gauge theory with a Higgs boson. The same technique allows us to calculate, at one-loop order, a neutrino electromagnetic form factor which is gauge invariant at all photon momenta, thus resolving a long-standing problem. We show how massless Goldstone bosons, not present in the {ital S} matrix, must be introduced into Gr…
Non-abelian gauge dynamics of slowly moving fermions
1987
We study the dynamics generated by local gauge invariance under a non-abelianSU(N) group for two nonrelativistic particles interacting through the effect of the group charges. We describe the local gauge invariant potential which contains the exchange of infinitely many gluons. We discuss the possible implications of our result.
GAUGE-HIGGS UNIFICATION MODELS WITH COSET SPACE DIMENSIONAL REDUCTION SCHEME
2009
We investigate the gauge-Higgs unification models within the scheme of the coset space dimensional reduction, beginning with two types of set up; fourteen-dimensional gauge theory with simple gauge groups and ten-dimensional gauge theory with direct product gauge groups. We found some phenomenologically acceptable models through an exhaustive search for the candidates of the coset spaces, the gauge group in higher dimension, and fermion representation.
Running soft parameters in SUSY models with multiple U(1) gauge factors
2012
Abstract We generalize the two-loop renormalization group equations for the parameters of the softly broken SUSY gauge theories given in the literature to the most general case when the gauge group contains more than a single Abelian gauge factor. The complete method is illustrated at two-loop within a specific example and compared to some of the previously proposed partial treatments.
BRST-driven cancellations and gauge invariant Green's functions
2004
We study a fundamental, all order cancellation operating between graphs of distinct kinematic nature, which allows for the construction of gauge-independent effective self-energies, vertices, and boxes at arbitrary order.
On the universal bundle for gravity
1991
Abstract We construct a supergravity type theory based on a superspace whose odd directions consist of a vector, together with a scalar representing a topological BRST shift symmetry. As such, the resulting theory is a theory of topological gravity. The gravitino is interpreted as a ghost field for this shift symmetry and plays the usual role of gauge field for local supersymmetry. Our construction is within the bundle of frames approach to superspace where covariant torsion constraints are analyzed, and we find that the resulting theory contains additional fields which are not present in existing theories of topological gravity. In particular, a minimal solution exists which contains a BRS…