Superfield formulation of the N=2 super-Yang-Mills model with central charge

The N = 2 super-Yang-Mills model with central charge is constructed in terms of the N = 1 superfields. The supersymmetric constraints generalizing the linear multiplet in the non-abelian case are found. This formulation is shown to be equivalent, using the supersymmetric Lagrange multipliers, to the previously known formulation of Fayet.     

The vanishing volume of N = 1 superspace

We show that the supergeometry of the new minimal formulation of N = 1 supergravity is a limiting case of the non-minimal supergeometry for which the volume of superspace vanishes. The action for supergravity in this case is then no longer the superdeterminant of the vielbein but is analogous to a special form of the Fayet-Iliopoulos term allowed only for the new minimal supergeometry. We discuss the restrictions on matter couplings imposed by the new and non-minimal supergeometries.     

Light-cone superspace and the ultraviolet finiteness of the N=4 model

Superspace in the light-cone frame takes a simple form. No auxiliary fields are necessary, and application to extended supersymmetries is straightforward. It is shown that the N=4 model, in a certain form of the light-cone gauge, is completely free of ultraviolet divergences in any order of perturbation theory. It follows that the β-function vanishes in any gauge, to all orders of perturbation theory. Our method differs from the conventional method in that we use only half the number of θ's as there are supersymmetry operators. All fields are unconstrained and independent of the $\text{θ}\text{'}\text{s}$.     

Group manifold first-order formulation of N=2, d=4 supergravity theory

In this paper, the so far lacking first-order formulation of N = 2 supergravity is obtained in the group manifold rheonomic symmetry approach. In order for the theory to be non-trivial it must contain, besides the pseudoconnection, also a 0-form matter multiplet which, moreover, provides the mechanism to generate the spin-l field kinetic term. It is explicitly shown how the O(2)～U(1) symmetry is realized not by a linear gauge transformation, rather by a rheonomic one.     

N = 2 supergravity action in terms of N = 1 superfields

We construct the full N = 2 supergravity action in terms of N = 1 supergravity and matter fields.     

N = 4 supergravity coupled to N = 4 matter and hidden symmetries

We present the N = 1 supergravity in 10 dimensions obtained by truncating the reduced N = 1 supergravity from 11 dimensions. This is further reduced to 4 dimensions to give SU(4) supergravity coupled to six SO(4) vector multiplets. As the reduction is from 10 dimensions, the theory is expected to have the symmetry SL(6R)_global×SO(6)_local, but we give a theoretical argument that this can be extended to SO(6,6)×SU(1,1)_global and SO(6)×SO(6)×U(1)_local.     

N = 4 Yang-Mills theory in terms of N = 3 and N = 2 light-cone superfields

The N = 4 Yang-Mills theory is truncated to an N = 3 Yang-Mills theory and to an N = 2 Yang-Mills theory coupled to an N = 2 Wess-Zumino field. The whole procedure is performed in the light-cone gauge. It is then shown that these theories are unique even if we only insist on N = 3 or N = 2 supersymmetry respectively. Finally we show in detail how the introduction of the fermionic Wess-Zumino field renders the one-loop self-energy finite.     

Off-shell N = 8 supersymmetry with central charges

Using a new technique of dimensional reduction by Legendre transformation we derive an off-shell formulation of the N = 8 extended supersymmetry algebra, which is realised in the maximally extended supergravity theory. The theory has an Sp(8) manifest global invariance and some of the fields satisfy differential constraints.     

N=2 extended superconformal algebra with “central” charges

We show how central charges may be incorporated in a superconformal (D = 4) algebra for N = 2. The charges are no longer truly central and so are at variance with the well-known theorems on (super-) symmetries of the S-matrix. We discuss the possible relevance of the algebra and justify our interest in it.     

Linearized superfield formulation of the new minimal N = 1 supergravity

A superfield version of the new minimal N = 1 Poincaré supergravity, recently proposed by Sohnius and West in components, is given at the linearized level. The action and corresponding supercurrent are obtained from an analysis of the superspace-translation tensor in a special case. Linearized torsions and curvatures can be computed in terms of the prepotentials.     

Linearized superfield formulation of the new non-minimal N = 1 supergravities

A superfield version of the two non-minimal N = 1 Poincaré supergravities, proposed by Rivelles and Taylor, is given at the linearized level. It is shown how the prepotentials, actions and supercurrents emerge from an analysis of the superspace-translation tensor in its non-minimal form. The linearized supergeometry is studied.     

Low energy constraints on N = 2 supersymmetric models

We derive constraints on the masses of mirror particles in N = 2 supersymmetric theories. We consider the K_L?K_S mass difference, the π → ev/π → μv branching ratio and the anomalous magnetic moment of the muon. The K_L?K_S mass difference gives a lower bound of 15 TeV on the mirror gauge scalar and mirror gauge fermion masses, under suitable assumptions.     

From N = 1 to N = 4 extended supersymmetric Yang-Mills fields in a covariant Wess-Zumino gauge

It is assumed that N = 1 supersymmetric Yang-Mills fields coupled to chiral matter fields can be renormalized in a covariant Wess-Zumino gauge with a minimal number of subtractions so that the Ward identities of supersymmetry, ordinary gauge invariance and matter-field-flavour symmetries are satisfied. The chiral Yukawa couplings are supposed to remain unrenormalized. I show that on the basis of these assumptions an N = 4 extended manifestly O(4) invariant theory can be constructed with finite Yukawa and φ⁴ couplings. A consequence of these non-renormalizations is the vanishing of the renormalization group β function.     

Bound states in N = 8 supergravity and N = 4 supersymmetric Yang-Mills theories

We present a study of possible bound states in N = 8 supergravity. We find evidence for the existence of multiplets of two-body bound states and expect that many-body bound states may exist as well. Our study is based on a calculation of Regge trajectories in the two-body scattering amplitudes of the lagrangian field theory. We also study Regge trajectories in N = 4 Yang-Mills theory and find evidence for a possible spin zero, SU(4) and gauge singlet, massless bound state. If such a state actually exists and supersymmetry is not broken, it may be a member of a supersymmetric multiplet which includes the graviton.     

Noncompact N=2 supergravity

A massive spin-one multiplet with central charge is coupled to N=2 supergravity. Compared to conventional gauge fields the anomalous magnetic moment of the spin-one particles is of the opposite sign. The construction of this theory is based on an N=2 supersymmetric gauge theory associated with the noncompact group SO(2,1). As a byproduct we present a convenient expression for the N=2 Einstein-Yang-Mills lagrangian.     

On-shell O(N) supergravity in superspace

We show that general considerations of the properties of free on-shell O(N) superfield strengths lead directly to linearized on-shell O(N) supergravity. We consequently obtain a formulation of the fully non-linear on-shell theories in which all fields are contained in the covariant derivatives.     

Linearized N = 2 superfield supergravity

We present the formulation of linearized SU(2) supergravity and U(2) conformal supergravity in terms of unconstrained N = 2 superfields: the gauge superfield, compensating superfields, gauge transformations, supertensors, actions and covariant derivatives.     

Magnetovacs in gauged N = 4 supergravity

A two-parameter family of supersymmetric background field solutions of the recently formulated version of gauged N = 4 supergravity is found. This constitutes strong evidence that the theory has stable vacua, despite energy densities that are unbounded below. The background geometries are metric products of (AdS)₂ × S₂, and there are covariantly constant magnetic and electric fields. For a special choice of parameters the (AdS)₂ factor becomes a flat Minkowski space and electric fields vanish.