16 research outputs found
Non-renormalization theorems of Supersymmetric QED in the Wess-Zumino gauge
The non-renormalization theorem of chiral vertices and the generalized
non-renormalization theorem of the photon self energy are derived in SQED on
the basis of algebraic renormalization. For this purpose the gauge coupling is
extended to an external superfield. This extension already provides detailed
insight into the divergence structure. Moreover, using the local supercoupling
together with an additional external vector multiplet that couples to the axial
current, the model becomes complete in the sense of multiplicative
renormalization, with two important implications. First, a Slavnov--Taylor
identity describing supersymmetry, gauge symmetry, and axial symmetry including
the axial anomaly can be established to all orders. Second, from this
Slavnov-Taylor identity we can infer a Callan-Symanzik equation expressing all
aspects of the non-renormalization theorems. In particular, the gauge
-function appears explicitely in the closed form.Comment: Latex, 47 page
Domain Walls and Superpotentials from M Theory on Calabi-Yau Three-Folds
Compactification of M theory in the presence of G-fluxes yields N=2
five-dimensional gauged supergravity with a potential that lifts all
supersymmetric vacua. We derive the effective superpotential directly from the
Kaluza-Klein reduction of the eleven-dimensional action on a Calabi-Yau
three-fold and compare it with the superpotential obtained by means of
calibrations. We discuss an explicit domain wall solution, which represents
five-branes wrapped over holomorphic cycles. This solution has a ``running
volume'' and we comment on the possibility that quantum corrections provide a
lower bound allowing for an AdS_5 vacuum of the 5-dimensional supergravity.Comment: 21 pages, harvmac, 1 figure, minor corrections and refs adde
Strong/Weak Coupling Duality from the Dual String
On compactification to six spacetime dimensions, the fundamental heterotic
string admits as a soliton a dual string whose effective worldsheet action
couples to the background fields of the dual formulation of six-dimensional
supergravity. On further toroidal compactification to four spacetime
dimensions, the dual string acquires an target-space duality. This
contains as a subgroup the axion-dilaton which corresponds to a
strong/weak coupling duality for the fundamental string. The dual string also
provides a new non-perturbative mechanism for enhancement of the gauge
symmetry.Comment: 23 pages LATE
Supergravity Unification
A review is given of the historical developments of 1982 that lead to the
supergravity unified model (SUGRA)with gravity mediated breaking of
supersymmetry. Further developments and applications of the model in the period
1982-85 are also discussed. The supergravity unified model and its minimal
version (mSUGRA) are currently among the leading candidates for physics beyond
the Standard Model. A brief note on the developments from the present vantage
point is included.Comment: Contribution to the Proceedings "Thirty Years of Supersymmetry",
October 13-15, 2000, Minnesota, US
Out of Equilibrium Dynamics of Supersymmetry at High Energy Density
We investigate the out of equilibrium dynamics of global chiral supersymmetry
at finite energy density. We concentrate on two specific models. The first is
the massive Wess-Zumino model which we study in a selfconsistent one-loop
approximation. We find that for energy densities above a certain threshold, the
fields are driven dynamically to a point in field space at which the fermionic
component of the superfield is massless. The state, however is found to be
unstable, indicating a breakdown of the one-loop approximation. To investigate
further, we consider an O(N) massive chiral model which is solved exactly in
the large limit. For sufficiently high energy densities, we find that for
late times the fields reach a nonperturbative minimum of the effective
potential degenerate with the perturbative minimum. This minimum is a true
attractor for O(N) invariant states at high energy densities, and this provides
a mechanism for determining which of the otherwise degenerate vacua is chosen
by the dynamics. The final state for large energy density is a cloud of
massless particles (both bosons and fermions) around this new nonperturbative
supersymmetric minimum. By introducing boson masses which softly break the
supersymmetry, we demonstrate a see-saw mechanism for generating small fermion
masses. We discuss some of the cosmological implications of our results.Comment: 31 pages, 15 figure
Twenty Years of SUGRA
A brief review is given of the developments of mSUGRA and its extensions
since the formulation of these models in 1982. Future directions and prospects
are also discussed.Comment: Invited talk at the International Conference BEYOND-2003, Schloss
Ringberg, Germany, June 10-14, 2003; 21 pages, Late
Non-renormalization theorems in softly broken SQED and the soft -functions
The renormalization of softly broken SQED is related to the one of
supersymmetric QED by using the construction with a local gauge supercoupling
and by taking into account softly broken anomalous axial U(1) symmetry. From
this extended model one obtains the non-renormalization theorems of SQED and
the counterterms of the soft breaking parameters as functions of the
supersymmetric counterterms. Due to the Adler-Bardeen anomaly of the axial
current an invariant regularization scheme does not exist, and therefore the
-functions of soft breaking parameters are derived from an algebraic
construction of the Callan-Symanzik equation and of the renormalization group
equation. We obtain the soft -functions in terms of the gauge
-function and of the anomalous dimension of the supersymmetric matter
mass. In particular, we find that the X-term of the scalar mass
-function as well as the gauge -function in are due to
the Adler-Bardeen anomaly of the axial symmetry.Comment: 28 page
Stochastic and parastochastic aspects of supersymmetric functional measures
This collection of selected reprints presents as broad a selection as possible, emphasizing formal and numerical aspects of Stochastic Quantization. It reviews and explains the most important concepts placing selected reprints and crucial papers into perspective and compact form