[en] The rate and corresponding gluon jet energy distribution for the process e⁺e^- → t anti tg are sensitive to the presence of anomalous dipole-like couplings of the top to the photon and Z at the production vertex as well as to the gluon itself. For sizeable anomalous couplings substantial derivations in the shape and magnitude of the gluon spectrum from the expectations of the Standard Model are anticipated. The authors explore the capability of the Next Linear Collider to either discover or place bounds on these types of top quark couplings through measurements of the gluon energy distribution. The resulting constraints are found to be quite complementary to those obtained using other techniques

[en] We consider the unification of the Einstein theory of gravity with a conformal invariant version of the standard model for electroweak interaction without the Higgs potential. In this theory, the evolution of the Universe and the elementary particle masses have one and the same cosmological origin. In the flat space limit, we get the σ-model version of the standard model. The cosmological consequences of such a unification are studied. The red shift formula and Hubble law are obtained under the conventional Friedmann assumption of homogeneous matter distribution. We show that the considered theory leads to a very small vacuum density of the Higgs field ρ^Cosmic_φ = 10^-34ρ_cr in contrast with the theory with the Higgs potential ρ^Higgs_φ =0⁵⁴ρ_cr. (author)

[en] Large charge density, unlike high temperature, may lead to the nonrestoration of global and gauge symmetries. Supersymmetric GUTs with the appealing scenario of unification scale being generated dynamically naturally contain global continuous R symmetries. We point out that the presence of a large R charge in the early Universe can lead to GUT symmetry nonrestoration. This provides a simple way out of the monopole problem. (author)

[en] The authors discuss the results of a global fit to precision data in supersymmetric models. They consider both gravity- and gauge-mediated models. As the superpartner spectrum becomes light, the global fit to the data typically results in larger values of χ². They indicate the regions of parameter space which are excluded by the data. The authors discuss the additional effect of the B(B → X_sγ) measurement. The analysis excludes chargino masses below M_Z in the simplest gauge-mediated model with μ > 0, with stronger constraints for larger values of tan β

[en] Attempts to understand the recent observation of an excess of events in the neutral and charged current channels at high-Q² at HERA has provided an excellent example of how experiments at both low and high energies can be used to simultaneously constrain scenarios which predict new physics beyond the Standard Model. In this talk the author discusses this subject from the point of view of the construction of new models of leptoquarks

[en] We present an effective lagrangian parameterization describing scalar, vector, and axial-vector bound states, originating from a strong breaking of the electroweak symmetry, based on the global symmetry SU(N)_L x SU(N)_R. In this approach vector and axial-vector bound states are gauge bosons associated to a hidden SU(N)_L x SU(N)_R symmetry. After the gauging of the electroweak symmetry, the corrections to the self-energies of the standard model gauge bosons are calculated and bounds on the parameter space of the model arising from precision measurements are studied. The self-energy corrections arise from spin-one mixings, pseudogoldstone loops, pseudogoldstone spin-one loops, and tadpole terms. The one-loop terms tend to decrease both isospin conserving and isospin violating corrections. Careful calculation for standard SU(8) QCD-scaled technicolor shows that strictly this model (which has, however, serious theoretical difficulties on its own) is still marginally allowed at present experimental precision. (orig.)

[en] I discuss the status of lattice computations of weak matrix elements. Much of the talk is devoted to a review of two topics in which lattice computations have, or are expected to have, a significant impact on particle physics phenomenology. These are (a) the recent computations of the (leptonic) decay constants of pseudoscalar heavylight mesons and (b) the prospects for lattice studies of semi-leptonic decays of B-mesons. (orig.)

[en] In a class of minimal supersymmetric left-right models of weak interactions where R parity is automatically conserved, we show that the spontaneous breakdown of parity cannot occur without the spontaneous breakdown of R parity. This intriguing result connects two physically different scales in supersymmetric models

[en] The abelian vortex dynamics in the abelian projection approach to non-abelian spin models is discussed. It is shown numerically that in the three-dimensional SU (2) spin model in the maximal abelian projection the abelian off-diagonal vortices are not responsible for the phase transition contrary to the diagonal vortices. A generalization of the abelian projection approach to SU (N) spin models is briefly discussed

[en] The W- and Z- strings occurring in the electroweak model are described. Physical arguments are given suggesting that bound states on the strings can stabilize the string solution for suitable parameters