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Erich Poppitz

Publications and source records attributed to Erich Poppitz.

86 records · Page 5Linked to original sources
arXiv1998

Dynamical Supersymmetry Breaking

Dynamical supersymmetry breaking is a fascinating theoretical problem. It is also of phenomenological significance. A better understanding of this phenomenon can help in model building, which in turn is useful in guiding the search for supersymmetry. In this article, we review the recent developments in the field. We discuss a few examples, which allow us to illustrate the main ideas in the subject. In the process, we also show how the techniques of holomorphy and duality come into play. Towards the end we indicate how these developments have helped in the study of gauge mediated supersymmetry breaking. The review is intended for someone with a prior knowledge of supersymmetry who wants to find out about the recent progress in this field.

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arXiv1997

Dynamical Supersymmetry Breaking---Why and How

This theoretical review is intended to give non-theorists a flavor of the ideas driving the current efforts to experimentally find supersymmetry. We discuss the main reasons behind the expectation that supersymmetry may be "just around the corner" and may be discovered in the near future. We use simple quantum-mechanical examples to illustrate the concept---and the power---of supersymmetry, the possible ways to break supersymmetry, and the dynamical generation of small scales. We then describe how this theoretical machinery helps shape our perception of what physics beyond the electroweak scale might be.

hep-ph↗
arXiv1997

Chiral Gauge Theories from D-Branes

We construct brane configurations leading to chiral four dimensional N=1 supersymmetric gauge theories. The brane realizations consist of intersecting Neveu-Schwarz five-branes and Dirichlet four-branes in non-flat spacetime backgrounds. We discuss in some detail the construction in a C^2/Z_M orbifold background. The infrared theory on the four-brane worldvolume is a four dimensional N=1 SU(N)^M gauge theory with chiral matter representations. We discuss various consistency checks and show that the spectral curves describing the Coulomb phase of the theory can be obtained once the orbifold brane construction is embedded in M-theory. We also discuss the addition of extra vectorlike matter and other interesting generalizations.

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arXiv1997

Some Remarks On Gauge-Mediated Supersymmetry Breaking

We investigate the communication of supersymmetry breaking to the Standard Model in theories of gauge mediated supersymmetry breaking with general weakly coupled messenger sectors. We calculate the one loop gaugino and two loop soft scalar masses for nonvanishing Str M^2 of the messenger sector. The soft scalar masses are sensitive to physics at scales higher than the messenger scale, in contrast to models with vanishing messenger supertrace. We discuss the implications of this ultraviolet sensitivity in theories with renormalizable and nonrenormalizable supersymmetry breaking sectors. We note that the standard relation, in minimal gauge mediation, between soft scalar and gaugino masses is altered in models with nonvanishing messenger supertrace.

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arXiv1996

Duality and Exact Results in Product Group Theories

We study the non-perturbative behavior of some N=1 supersymmetric product-group gauge theories with the help of duality. As a test case we investigate an SU(2)xSU(2) theory in detail. Various dual theories are constructed using known simple-group duality for one group or both groups in succession. Several stringent tests show that the low-energy behavior of the dual theories agrees with that of the electric theory. When the theory is in the confining phase we calculate the exact superpotential. Our results strongly suggest that, in general, dual theories for product groups can be constructed in this manner, by using simple-group duality for both groups. Turning to a class of theories with SU(N)xSU(M) gauge symmetry we study the renormalization group flows in the space of the two gauge couplings and show that they are consistent with the absence of phase transitions. Finally, we show that a subset of these theories, with SU(N)xSU(N-1) symmetry break supersymmetry dynamically.

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arXiv1996

Holomorphic Anomalies and the Nonrenormalization Theorem

It has been argued that the superpotential can be renormalized in the presence of massless particles. Possible implications which have been considered include the restoration of supersymmetry at higher loops or a shift to a supersymmetric vacuum state. We argue that even in the presence of massless particles, there are no new contributions to the superpotential at any order in perturbation theory. This confirms the utility of the Wilsonian superpotential for analyzing the moduli space of the low energy theory.

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arXiv1995

Low-Energy Supersymmetry Breaking and Fermion Mass Hierarchies

In models with low-energy supersymmetry breaking, an anomalous Abelian horizontal gauge symmetry can simultaneously explain the fermion mass hierarchy and the values of the $μ$ and $B$ terms. We construct an explicit model where the anomaly is cancelled by the Green-Schwarz mechanism at the string scale. We show that with our charge assignments, the breaking of the horizontal symmetry generates the correct order of magnitude and correct hierarchy for all Yukawa couplings.

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arXiv1995

Some Examples of Chiral Moduli Spaces and Dynamical Supersymmetry Breaking

We investigate the low-energy dynamics of $SU(N)$ gauge theories with one antisymmetric tensor field, $N - 4 + N_f$ antifundamentals and $N_f$ fundamentals, for $N_f \le 3$. For $N_f = 3$ we construct the quantum moduli space, and for $N_f < 3$ we find the exact quantum superpotentials. We find two large classes of models with dynamical supersymmetry breaking. The odd $N$ theories break supersymmetry once appropriate mass terms are added in the superpotential. The even $N$ theories break supersymmetry after gauging an extra chiral $U(1)$ symmetry.

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arXiv1995

Destabilizing Divergences in Supergravity Theories at Two Loops

We examine the stability of the mass hierarchy in hidden-sector supergravity theories. We show that a quadratically divergent tadpole can appear at two loops, even in minimal supergravity theories, provided the theory has a gauge- and global-symmetry singlet with renormalizable couplings to the visible fields. This tadpole can destabilize the hierarchy. We also find a quadratically divergent two-loop contribution to the field-dependent vacuum energy. This result casts doubt on the efficacy of the "LHC mechanism" for controlling quadratic divergences. We carry out the two-loop calculation in a manifestly supersymmetric formalism, and explain how to apply the formalism in the presence of supersymmetry breaking to derive radiative corrections to the supersymmetric and soft supersymmetry-breaking operators. Our approach greatly simplifies the calculation and guarantees consistency of our results with the underlying supergravity framework.

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arXiv1994

The R Axion From Dynamical Supersymmetry Breaking

All generic, calculable models of dynamical supersymmetry breaking have a spontaneously broken $R$ symmetry and therefore contain an $R$ axion. We show that the axion is massive in any model in which the cosmological constant is fine-tuned to zero through an explicit $R$-symmetry-breaking constant. In visible-sector models, the axion mass is in the 100 MeV range and thus evades astrophysical bounds. In nonrenormalizable hidden-sector models, the mass is of order of the weak scale and can have dangerous cosmological consequences similar to those already present from other fields. In renormalizable hidden- sector models, the axion mass is generally quite large, of order $10^7$ GeV. Typically, these axions are cosmologically safe. However, if the dominant decay mode is to gravitinos, the potentially large gravitino abundance that arises from axion decay after inflation might affect the successful predictions of big-bang nucleosynthesis. We show that the upper bound on the reheat temperature after standard inflation can be competitive with or stronger than bounds from thermal gravitino production, depending on the model and the gravitino mass.

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arXiv1994

Low-Energy Kahler Potentials in Supersymmetric Gauge Theories with (ALMOST) Flat Directions

We derive the supersymmetric low-energy effective theory of the D-flat directions of a supersymmetric gauge theory. The Kahler potential of Affleck, Dine and Seiberg is derived by applying holomorphic constraints which manifestly maintain supersymmetry. We also present a simple procedure for calculating all derivatives of the Kahler potential at points on the flat direction manifold. Together with knowledge of the superpotential, these are sufficient for a complete determination of the spectrum and the interactions of the light degrees of freedom. We illustrate the method on the example of a chiral abelian model, and comment on its application to more complicated calculable models with dynamical supersymmetry breaking.

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arXiv1993

Destabilizing Divergences in Supergravity-Coupled Supersymmetric Theories

Nonrenormalizable couplings in supergravity-coupled supersymmetric theories can give rise to power-law divergences that destabilize the weak-scale hierarchy. For the case of the standard-model gauge group, the problem can arise in theories with \321 gauge-singlet chiral superfields. The minimal supersymmetric standard model is free from such destabilizing divergences.

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