The Status of Supersymmetry

Supersymmetry searches are about to enter an important new era. With LEP 200 and the Main Injector, they will, for the first time, begin to probe significant regions of the supersymmetric parameter space. There is a real chance that supersymmetry might indeed be found before the advent of the LHC.Comment: Invited talk given at PbarP95, May 9-13, 1995, Fermilab. This summary is intended for experimentalist

Linear and nonlinear realizations of superbranes

The coordinate transformations which establish the direct relationship between the actions of linear and nonlinear realizations of supermembranes are proposed. It is shown that the Rocek-Tseytlin constraint known in the framework of the linear realization of the theory is simply equivalent to a limit of a "pure" nonlinear realization in which the field describing the massive mode of the supermembrane puts to zero.Comment: 8 pages, LaTeX + espcrc2.sty The talk given at the D. Volkov Memorial Conference SQFT, July, 25-29, 200

Matter couplings in partially broken extended supersymmetry

We use nonlinear realizations to describe the spontaneous breaking of $N=2$ supersymmetry to $N=1$ in four dimensions. We identify the Goldstone multiplet with an $N=1$ chiral superfield, and show that chiral $N=1$ matter is consistent with the partially broken $N=2$ supersymmetry. We find that the chiral matter can be in any representation of the gauge group; no mirror particles are required. We present the Goldstone action and the general couplings to $N=1$ matter to the first nontrivial order in the scale of symmetry breaking.Comment: JHU-TIPAC-94011, 9 pages. References adde

Comments on Multiple M2-branes

Recently a three-dimensional field theory was derived that is consistent with all the symmetries expected of the worldvolume action for multiple M2-branes. In this note we examine several physical predictions of this model and show that they are in agreement with expected M2-brane dynamics. In particular, we discuss the quantization of the Chern-Simons coefficient, the vacuum moduli space, a massive deformation leading to fuzzy three-sphere vacua, and a possible large n limit. In this large n limit, the fuzzy funnel solution correctly reproduces the mass of an M5-brane.Comment: 18 pages. Published versio

Quantum Corrections to Deep Bags

Nontopological solitons, or ``bags,'' can arise when fermions acquire their mass through a Yukawa coupling to some scalar field. Bags have played an important role in models of baryons, nuclei, and more recently, in the idea that a Higgs condensate may form around a very heavy top quark. It has been claimed that deep bags, which correspond to tightly-bound states of fermions, will form when the Yukawa coupling is strong. Quantum corrections, however, are significant in this regime. We examine the effects of these quantum corrections on the formation of nontopological solitons in an exactly solvable large-$N$ model. We find that quantum bags differ dramatically from those of the classical theory. In particular, for large Yukawa coupling, the bags remain shallow and the fermions weakly bound.Comment: Talk given at the XXVI Int. Conf. on High Energy Physics, August, 1992 LATEX file, 7 pages + 2 figures available upon request, JHU-TIPAC-92002