Broken (1, 0) supergraphity

The usual (1, 0) supergraph techniques are extended to account for supersymmetry breaking terms. Several possible breaking lagrangians are contemplated and the consistency of our modified super-Feynman rules is checked through a number of explicit supergraph evaluations. They might be of practical relevance in dealing with non-linear σ-models whenever supersymmetry is broken.     

Gauge-invariant effective lagrangians for goldstone-like particles of supersymmetric technicolor models

We point out that generally the low-energy spectrum in supersymmetric technicolor models contains quasi-Goldstone fermions and quasi-Goldstone bosons in addition to the usual (pseudo)- Goldstone bosons. Using the language of Kähler geometry, we present a step-by-step procedure for constructing gauge-invariant non-linear lagrangians involving the fermionic and bosonic Goldstone particles in situations in which supersymmetry is preserved. Both the cases of fully gauged and partially gauged global symmetries are considered. We discuss the dynamical version of the super-Higgs mechanism, and we illustrate it with the supersymmetric Susskind-Weinberg technicolor model.     

Effective lagrangian for supersymmetric theories with intermediate breaking scale

We investigate effective lagrangians in supersymmetric models broken spontaneously at an intermediate energy (～ μ ? M_GUT). It is shown to all orders in perturbation theory that the low-energy interactions of light particles are described by an effective lagrangian with explicit but soft supersymmetry breaking of order μ² / M_GUT.     

Effective chiral hadron lagrangian with anomalies and skyrme terms from quark flavour dynamics

By bosonization of an extended Nambu-Jona-Lasinio type of quark model with explicit breaking of chiral U(n) × U(n) symmetry we derive a effective low-energy lagrangian of composite scalar, pseudoscalar, vector and axial-vector mesons. This lagrangian contains the gauged Wess-Zumino term as well as higher order derivative terms of the Skyrme type, the coefficients of which agree with recent phenomenological estimates. In particular, the value predicted for the strength of the standard fourth-order Skyrme term is in satisfactory agreement with the results obtained by fitting the nucleon and delta masses. Our effective chiral lagrangian reproduces the wealth of the results of successful phenomenological lagrangians as, e.g. soft-pion theorems, Goldberger-Treiman relations, PCAC, the KSFR relation, the (approximate) Weinberg relation, etc. Moreover, the predicted mass spectra and decay constants of composite mesons are in qualitative agreement with the experimental findings. Furthermore, when electroweak interactions are included the lagrangian contains vector (axial-vector) dominance based on field-current identities.     

Hidden constants: The θ parameter of QCD and the cosmological constant of N = 8 supergravity

For field theories that include the abelian gauge field A_μν? the field equations allow an arbitrary integration constant, which does not appear in the lagrangian but which does affect the physics. We present two applications: (i) the θ parameter of effective lagrangians for chiral symmetry breaking in QCD, and (ii) the cosmological constant in N = 8 supergravity, which does not require a gauging of the O(8) symmetry, but is rather due to a spontaneous breakdown of supersymmetry.     

Non-linear realizations of supersymmetry with off-shell central charges

We present a new class of non-linear realizations of the extended supersymmetry algebra with central charges. They were obtained by applying the technique of dimensional reduction by Legendre transformation to a non-linear realization without central charges in one higher dimension. As a result an off-shell central charge is obtained. The non-linear lagrangian is the same as in the case of vanishing central charge. On-shell the central charge vanishes so this non-linear realization differs from that without central charges only off-shell. We work in two dimensions and discuss its extension to higher dimensions.     

Dynamical stability of the BRS supersymmetry and the Gribov problem

The stability of the Becchi-Rouet-Stora supersymmetry is studied on the basis of a simple non-gauge model invariant under BRS supersymmetry. The Nambu-Goldstone theorem is stated and the spontaneous breakdown of the BRS supersymmetry is illustrated by the above non-gauge model. This indicates that the dynamical stability of BRS supersymmetry in non-abelian gauge theories should also be carefully examined, if one takes the Faddeev-Popov lagrangian as a basis of the formal canonical treatment. We show that a better understanding of the Gribov problem is required to establish the stability of the BRS supersymmetry in non-abelian gauge theories to non-perturbative accuracy.     

Secret supersymmetry

We present new non-linear realizations of the N = 1 supergravity algebra. They allow us to build interesting realistic models of the four forces of nature. These models are different from all previous ones in that particles do not appear in (broken) supersymmetric multiplets.These new non-linear realizations also permit us to construct the effective low-energy lagrangian of an arbitrary supergravity theory in which supersymmetry is spontaneously broken. We are thus able to analyze what are the model-independent low-energy effects of supergravity. We find that the number of Higgs fields and the way they couple to quark and lepton matter is a feature which distinguishes supersymmetric theories from non-supersymmetric ones.     

Massive vector multiplets in supergravity

Starting from a vector multiplet we construct general lagrangians using the tensor calculus. After a Weyl rescaling and other field redefinitions we find lagrangians for the massive spin $\text{(1,}\text{1}\text{2}\text{,}\text{1}\text{2}\text{, 0)}$ model coupled to supergravity. Among the class of lagrangians which we consider we find no supersymmetry breaking.     

Multicentre metrics and harmonic superspace

We develop a procedure for constructing a possible harmonic superspace lagrangian for any d = 4 multicentre metric and show that the lagrangians leading to such metrics are characterized by the existence of a U(1) of Pauli-Gursey invariance. As an application, the mixed Eguchi-Hanson-Taub-NUT metric is shown, by explicit calculations, to be the double Taub-NUT metric.     

Supersymmetry in Anti-de Sitter Space

We review the renormalization of the ground state solution of extended supergravity and super-symmetric Kaluza-Klein theories. The computation of an adiabatic expansion of the effective action to the one-loop order yields the result that a linear superfield insertion in the superpotential is needed, in order to renormalize the nonvanishing one-particle-irreducible one-point functions, whereas supersymmetry is preserved at each extremum of the effective potential. The calculation of the one-particle-irreducible two-and three-point functions shows that neither the mass nor the interaction lagrangians get renormalized to the one-loop order. We conclude that the one-loop effects proportional to the contraction parameter of the curved background space force a violation of the no-renormalization theorem.     

On goldstone fields in supersymmetric theories

Some aspects concerning the spontaneous breakdown of global internal symmetries in N = 1 supersymmetric theories are discussed. They can be relevant in the context of supersymmetric preon models. We emphasize the connection of Goldstone dynamics to the linear model. Several statements about the number of Goldstone fields are made. The structure of non-linear lagrangians is discussed. In addition, we consider questions concerning complementarity.     

Higgs bosons in supersymmetric models (II). Implications for phenomenology

We discuss a wide range of phenomenological issues involving the production and decay of Higgs bosons. We focus on a minimal two-doublet supersymmetry model with soft supersymmetry breaking.     

Relatively and supersymmetries

We show how the supersymmetry transformations follow from the relativization of a pseudoclassical lagrangian describing particles with spin.     

Baryon-antibaryon asymmetry in a model with domain structure and soft CP violation

We consider a model with an abelian gauge symmetry, a Higgs potential involving two scalar fields, and two spinor fields coupled to the scalars through Yukawa couplings. The model accomodates soft violation of charge conjugation, and a domain structure of the universe with two different types of domains, which have identical energy but are governed by different effective lagrangians. The effective lagrangian has complex c-number coefficients that become parts of effective coupling constants, and these are different in the two kinds of domains. In spite of that fact the model neither predicts any domain-dependent effects, nor any particle-antiparticle asymmetries within domains.     

Relation between different auxiliary field formulations of N = 1 supergravity coupled to matter

We establish the connection between the old minimal set of auxiliary fields, the new minimal set and the Breitenlohner set. We show that the class of interactions which can be described by the latter two sets are particular cases of the interactions described in the old minimal set. The old and new minimal sets of auxiliary fields are equivalent for R-symmetric lagrangians. The precise correspondence of the bosonic part of the lagrangians in the two minimal formulations is exhibited. In particular, this equivalence shows that one can have both a Fayet-Iliopoulos term and spontaneously broken supersymmetry with vanishing cosmological constant.     

Decoupling in supersymmetric theories

We examine the decoupling of massive states in supergravity theories. Using superspace functional techniques to “integrate out” the massive modes we derive the effective low-energy lagrangian. The technique is extended to the case of large supersymmetry breaking and we show how the effective lagrangian correctly accounts for vacuum expectation values of massive fields. We discuss the structure of effective theories following from the superstring in which the effects of Kaluza-Klein modes and states massive after intermediate scale breaking are included. It is shown in the case of large intermediate scale breaking the theory should possess discrete symmetries to protect light states from large supersymmetry breaking and we list the conditions for viable models.     

Quarks and leptons as composite goldstone fermions

A dynamical scheme for composite quarks and leptons is proposed in which the observed fermions are Goldstone particles of spontaneously broken supersymmetry. Their residual interactions are described by a minimal effective lagrangian which invokes a non-linear realization of sypersymmetry. Possible experimental consequences are studied and it is found that the most conspicuous signature of this scheme would be a dramatic increase in the lepton pair production in hadronic collisions, particularly in $\text{pp}$ scattering, at high energy.