Brane Dynamics From Non-Linear Realizations

The action for a non-BPS p=2 brane embedded in a flat N=1, D=4 target superspace is obtained through the method of nonlinear realizations of the associated super-Poincare symmetries. The brane excitation modes correspond to the Nambu-Goldstone degrees of freedom resulting from the broken space translational symmetry and the target space supersymmetries. The action for this p=2 brane is found to be an invariant synthesis of the Akulov-Volkov and Nambu-Goto actions. The dual D2-brane Born-Infeld action is derived. The invariant coupling of matter fields localized on the brane to the Nambu-Goldstone modes is also obtained.Comment: 37 pages, no figures, revised version to appear in Phys. Rev.

Supersymmetric multi-Higgs doublet model with non-linear electroweak symmetry breaking

The electroweak symmetry is nonlinearly realized in an extension of the minimal supersymmetric standard model (MSSM) through an additional pair of constrained Higgs doublet superfields. The superpotential couplings of this constrained Higgs doublet pair to the MSSM Higgs doublet pair catalyze their vacuum expectation values. The Higgs and Higgsino-gaugino mass spectrum is presented for several choices of supersymmetry (SUSY) breaking and Higgs superpotential mass parameters. The additional vacuum expectation values provided by the constrained fields can produce a phenomenology quite different than that of the MSSM .Comment: 41 pages, 16 figure

Leaving the BPS bound: Tunneling of classically saturated solitons

We discuss quantum tunneling between classically BPS saturated solitons in two-dimensional theories with N=2 supersymmetry and a compact space dimension. Genuine BPS states form shortened multiplets of dimension two. In the models we consider there are two degenerate shortened multiplets at the classical level, but there is no obstruction to pairing up through quantum tunneling. The tunneling amplitude in the imaginary time is described by instantons. We find that the instanton is nothing but the 1/4 BPS saturated ``wall junction,'' considered previously in the literature in other contexts. Two central charges of the superalgebra allow us to calculate the instanton action without finding the explicit solution (it is checked, though, numerically, that the saturated solution does exist). We present a quantum-mechanical interpretation of the soliton tunneling.Comment: LaTeX, 22 pages, 9 figures (eps

Oscillating p-Branes

Coset methods are used to construct the action describing the dynamics associated with the spontaneous breaking of the Poincare symmetries of D dimensional space-time due to the embedding of a p-brane with codimension N=D-p-1. The resulting world volume action is an ISO(1,p+N) invariant generalization of the Nambu-Goto action in d=p+1 dimensional space-time. Analogous results are obtained for an AdS p-brane with codimension N embedded in D dimensional AdS space, yielding an SO(2,p+N) invariant version of the Nambu-Goto action in d=p+1 dimensional space-time. Attention is focused on a supersymmetric extension of the D=6 Minkowski space case with an embedded p=3 brane; a particular realization of which is provided by a non-BPS vortex. Here both the Nambu-Goto-Akulov-Volkov action and its dual tensor form are presented.Comment: 25 pages, no figure

Brane Vector Phenomenology

Local oscillations of the brane world are manifested as masssive vector fields. Their coupling to the Standard Model can be obtained using the method of nonlinear realizations of the spontaneously broken higher dimensional space-time symmetries, and to an extent, are model independent. Phenomenological limits on these vector field parameters are obtained using LEP collider data and dark matter constraints.Comment: 3 pages, 2 figures, late

Higgs Decays and Brane Gravi-vectors

Higgs boson decays in flexible brane world models with stable, massive gravi-vectors are considered. Such vectors couple bilinearly to the Standard Model fields through either the Standard Model energy-momentum tensor, the weak hypercharge field strength or the Higgs scalar. The role of the coupling involving the extrinsic curvature is highlighted. It is found that within the presently allowed parameter space, the decay rate of the Higgs into two gravi-vectors (which would appear as an invisible Higgs decay) can be comparable to the rate for any of the Standard Model decay modes.Comment: 5 pages, 11 figures, revte