21,680 research outputs found
Supersymmetric Yang-Mills-Chern-Simons theory
We prove that three-dimensional N=1 supersymmetric Yang-Mills-Chern-Simons
theory is finite to all loops. This leaves open the possibility that different
regularization methods give different finite effective actions. We show that
for this model dimensional regularization and regularization by dimensional
reduction yield the same effective action.Comment: 6 pages, 1 figure, latex, espcrc2. Contribution to the Proceedings of
the 30th Ahrenshoop Symposium on the Theory of Elementary Particles, edited
by D. Lust, H.-J. Otto and G. Weigt, to appear in Nuclear Physics B,
Proceedings Supplemen
Early Thoughts on the Violence of May 13 and 14, 1998, in Jakarta
Page range: 75-10
Subcritical Superstrings
We introduce the Liouville mode into the Green-Schwarz superstring. Like
massive supersymmetry without central charges, there is no kappa symmetry.
However, the second-class constraints (and corresponding Wess-Zumino term)
remain, and can be solved by (twisted) chiral superspace in dimensions D=4 and
6. The matter conformal anomaly is c = 4-D < 1. It thus can be canceled for
physical dimensions by the usual Liouville methods, unlike the bosonic string
(for which the consistency condition is c = D <= 1).Comment: 9 pg., compressed postscript file (.ps.Z), other formats (.dvi, .ps,
.ps.Z, 8-bit .tex) available at
http://insti.physics.sunysb.edu/~siegel/preprints/ or at
ftp://max.physics.sunysb.edu/preprints/siege
Momumentum Analyticity and Finiteness of Compactified String Amplitudes, Part I: Tori
We generalize to the case of compactified superstrings a construction given
previously for critical superstrings of finite one loop amplitudes that are
well-defined for all external momenta. The novel issues that arise for
compactified strings are the appearance of infrared divergences from the
propagation of massless strings in four dimensions and, in the case of orbifold
schemes, the contribution of tachyons in partial amplitudes with given spin
structure and twist sectors. Methods are presented for the resolution of these
problems and expressions for finite amplitudes are given in terms of double and
single dispersion relations, with explicit spectral densities.Comment: 18 pages, te
Closed String Amplitudes from Gauge Fixed String Field Theory
Closed string diagrams are derived from cubic open string field theory using
a gauge fixed kinetic operator. The basic idea is to use a string propagator
that does not generate a boundary to the world sheet. Using this propagator and
the closed string vertex, the moduli space of closed string surfaces is
covered, so closed string scattering amplitudes should be reproduced. This
kinetic operator could be a gauge fixed form of the string field theory action
around the closed string vacuum.Comment: 10 pages, revtex, 3 figures. Discussion on the covering of moduli
expanded, version to appear in PR
Invariances and Equations of Motion in Double Field Theory
We investigate the full set of equations of motion in double field theory and
discuss their O(D,D) symmetry and gauge transformation properties. We obtain a
Ricci-like tensor, its associated Bianchi identities, and relate our results to
those with a generalized metric formulation.Comment: 24 page
Progress in the development of an 88-mm bore 10 Tn3Sn dipole magnet
A 10 T, 2-layer cos(&thetas;)-dipole model magnet with an 88 mm clear bore utilizing an advanced powder-in-tube Nb3Sn conductor is being developed for the LHC. A dedicated conductor development program has resulted in a well performing Rutherford cable containing strands that uniquely exhibit both an overall current density of 600 A/mm2 @ 11 T and filaments with a diameter of 20 ¿m. The resistance between crossing strands amounts to 30-70 ¿¿ by insertion of a stainless steel core. After being exposed to a transverse pressure of 200 MPa identical cables show negligible permanent degradation of the critical current. The mechanical support structure is further optimized in order to reduce the peak stress in the mid-plane to below 130 MPa at full excitation and to control the pre-stress build-up during system assembly. Prior to the manufacturing of the final coils a dummy 2-layer pole is wound, heat-treated at 675°C and vacuum resin impregnated. This paper presents the current status of the magnet development program and highlights in particular the successful conductor developmen
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