Search results for "supersymmetric gauge theory"
showing 10 items of 20 documents
Subleading Regge limit from a soft anomalous dimension
2018
Wilson lines capture important features of scattering amplitudes, for example soft effects relevant for infrared divergences, and the Regge limit. Beyond the leading power approximation, corrections to the eikonal picture have to be taken into account. In this paper, we study such corrections in a model of massive scattering amplitudes in N = 4 super Yang-Mills, in the planar limit, where the mass is generated through a Higgs mechanism. Using known three-loop analytic expressions for the scattering amplitude, we find that the first power suppressed term has a very simple form, equal to a single power law. We propose that its exponent is governed by the anomalous dimension of a Wilson loop w…
Intersecting Defects and Supergroup Gauge Theory
2021
Journal of physics / A 54(43), 435401 (2021). doi:10.1088/1751-8121/ac2716
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.
Induced scalar potentials for hypermultiplets
1997
Charged BPS hypermultiplets can develop a non-trivial self-interaction in the Coulomb branch of an N=2 supersymmetric gauge theory, whereas neutral BPS hypermultiplets in the Higgs branch may also have a non-trivial self-interaction in the presence of Fayet-Iliopoulos terms. The exact hypermultiplet low-energy effective action (LEEA) takes the form of the non-linear sigma-model (NLSM) with a hyper-K"ahler metric. A non-trivial scalar potential is also quantum-mechanically generated at non-vanishing central charges, either perturbatively (Coulomb branch), or non-perturbatively (Higgs branch). We calculate the effective scalar potentials for (i) a single charged hypermultiplet in the Coulomb …
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…
High-energy evolution to three loops
2018
The Balitsky-Kovchegov equation describes the high-energy growth of gauge theory scattering amplitudes as well as nonlinear saturation effects which stop it. We obtain the three-loop corrections to this equation in planar $\mathcal{N}=4$ super Yang-Mills theory. Our method exploits a recently established equivalence with the physics of soft wide-angle radiation, so-called non-global logarithms, and thus yields at the same time the three-loop evolution equation for non-global logarithms. As a by-product of our analysis, we develop a Lorentz-covariant method to subtract infrared and collinear divergences in cross-section calculations in the planar limit. We compare our result in the linear re…
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.
A partial elucidation of the gauge principle
2008
The elucidation of the gauge principle "is the most pressing problem in current philosophy of physics" said Michael Redhead in 2003. This paper argues for two points that contribute to this elucidation in the context of Yang–Mills theories. (1) Yang–Mills theories, including quantum electrodynamics, form a class. They should be interpreted together. To focus on electrodynamics is potentially misleading. (2) The essential role of gauge and BRST symmetries is to provide a local field theory that can be quantized and would be equivalent to the quantization of the non-local reduced theory. If this is correct, the gauge symmetry is significant, not so much because it implies ontological conseque…
Gauge coupling instability and dynamical mass generation in N=1 three-dimensional supersymmetric QED
1999
Using superfield Dyson-Schwinger equations, we compute the infrared dynamics of the semi-amputated full vertex, corresponding to the effective running gauge coupling, in N-flavor N51 three-dimensional supersymmetric QED. It is shown that the presence of a supersymmetry-preserving mass for the matter multiplet stabilizes the infrared gauge coupling against oscillations present in the massless case, and we therefore infer that the massive vacuum is thus selected at the level of the ~quantum! effective action. We further demonstrate that such a mass can indeed be generated dynamically in a self-consistent way by appealing to the superfield Dyson-Schwinger gap equation for the full matter propa…
Relations for Einstein–Yang–Mills amplitudes from the CHY representation
2017
We show that a recently discovered relation, which expresses tree-level single trace Einstein-Yang-Mills amplitudes with one graviton and $(n-1)$ gauge bosons as a linear combination of pure Yang-Mills tree amplitudes with $n$ gauge bosons, can be derived from the CHY representation. In addition we show that there is a generalisation, which expresses tree-level single trace Einstein-Yang-Mills amplitudes with $r$ gravitons and $(n-r)$ gauge bosons as a linear combination of pure Yang-Mills tree amplitudes with $n$ gauge bosons. We present a general formula for this case.