120192541
Discrete and Abelian lattice gauge theories
Gauge-invariant discrete and Abelian (X-Y) spin models with compact degrees of freedom are studied in (D + 1) Euclidean (“space-time”) dimensions (D ⩽ 3). They are formulated in terms of quantum Hamiltonians on a D-dimensional spatial lattice. In this approach the periodic Gaussian and Abelian models are identical. 
 
Duality transformations are obtained which relate the topological excitations of one model to the fundamental quantum spin excitations of another. These motivate the extension of the usual gauge-invariant structure to “gauge invariance of the third kind” which involves degrees of freedom associated with the surfaces of the plaquettes. 
 
The nature of the excited states and the behaviour of the order (and disorder) parameters are discussed in various limits of the coupling constants. For both discrete and Abelian theories the behaviour of the order parameter (the Wilson loop) depends crucially on whether the spins in the theory carry the fundamental unit of charge or a multiple of it.
9607753
Anomalous creation of branes
In certain circumstances when two branes pass through each other a third brane is produced stretching between them. We explain this phenomenon by the use of chains of dualities and the inflow of charge that is required for the absence of chiral gauge anomalies when pairs of D-branes intersect.
121062482
N=4 Yang-Mills and N=8 Supergravity as Limits of String Theories
The formulation of supersymmetric string theories in ten dimensions is generalized to incorporate compactified dimensions. Expressions for the one-loop four-particle S -matrix elements of N = 4 Yang-Mills and N = 8 supergravity in four dimensions are obtained by studying the string-theory loop amplitudes in the limit that the radii of the compactified dimensions and the Regge slope parameter simultaneously approach zero. If certain patterns that emerge should persist in the higher orders of perturbation theory, then N = 4 Yang-Mills in four dimensions would be ultraviolet finite to all orders, whereas N = 8 supergravity in four dimensions would have ultraviolet divergences starting at three loops.
120539667
Anomaly cancellations in supersymmetric D = 10 gauge theory and superstring theory☆
Abstract Supersymmetric ten-dimensional Yang-Mills theory coupled to N = 1, D = 10 supergravity has gauge and gravitational anomalies that can be partially cancelled by the addition of suitable local interactions. The remaining pieces of all the anomalies cancel if the gauge group is SO(32) or E 8 × E 8 . These cancellations are automatically incorporated in the type I superstring theory based on SO(32). A superstring theory for E 8 × E 8 has not yet been constructed.
121755839
PHASE CONTOURS AND BOOTSTRAPS. I.
123230985
Off-shell states in the dual model
Abstract We present a class of Lorentz invariant, gauge invariant off-shell amplitudes for the ordinary Veneziano and Ramond-Neveu-Schwarz dual models. They correspond to interactions with the string which are local in space-time.
118224501
An update on passive correctors for the SSC dipole magnets
The concept of correction of the magnetization sextupole became a topic of discussion as soon as it was realized that superconductor magnetization could have a serious effect on the SSC beam during injection. Several methods of correction were proposed. These included (1) correction with active bore tube windings like those on the HERA machine which correct out magnetization sextupole and the sextupole due to iron saturation, (2) correction with persistent sextupole windings mounted on the bore tube (3) correction using passive superconductor (4) correction using ferromagnetic material, and (5) correction using oriented magnetized materials. This report deals with the use of passive superconductor to correct the magnetization sextupole. Two basic methods are explored in this report: (1) One can correct the magnetization sextupole by changing the diameter of the superconductor filaments in one or more blocks of the SSC dipole. (2) One can correct the magnetization sextupole and decapole by mounting passive superconducting wires on the inside of the SSC dipole coil bore. In addition, an assessment of the contribution of each conductor in the dipole to the magnetization sextupole and decapole is shown. 38 refs, 25 figs., 15 tabs.
121568572
Progress on the focus coils for the MICE channel
122592091
DESIGN ISSUES FOR THE SUPERCONDUCTING MAGNET THAT GOES AROUND THE LIQUID HYDROGEN ABSORBER FOR THE MUON IONIZATION COOLING EXPERIMENT (MICE)
This report describes the design issues that are associated with a superconducting focusing solenoid that goes around a liquid hydrogen absorber for the Muon Ionization Cooling Experiment (MICE) proposed for the Rutherford Appleton Laboratory [1-3]. The solenoid consists of two superconducting coils that may operated at the same polarity or at opposite polarities. As a result, the coils and their support structure must be designed to carry a 360-ton inter-coil force that is forcing the coils apart along their axis. The basic design parameters for the focusing magnet are discussed. The magnet and its cryostat are designed so that the absorber can be assembled and tested before installation into the pretested focusing solenoid. Safety requirements for MICE dictate that the insulating vacuum for the superconducting magnet be separated from the insulating vacuum for the absorber and that both vacuum be separated from the experiment vacuum and the vacuum within adjacent RF cavities. The safety issues associated with the arrangement of the various vacuums in the MICE focusing modules are presented. The effect of magnet operation and magnet quench on the liquid hydrogen absorber is also discussed.
54925012
MEASUREMENT OF RESISTANCE AND STRENGTH OF CONDUCTOR SPLICES IN THE MICE COUPLING MAGNETS
The superconducting magnets for the Muon Ionization Cooling Experiment [1] (MICE) use a copper based Nb‐Ti conductor with un‐insulated dimensions of 0.95 by 1.60 mm. There may be as many as twelve splices in one MICE superconducting coupling coil. These splices are to be wound in the coil. The conductor splices produce Joule heating, which may cause the magnet to quench. A technique of making conductor splices was developed by ICST. Two types of 1‐meter long of soldered lap‐joints have been tested. Side‐by‐side splices and up‐down one splices were studied theoretically and experimentally using two types of soft solder made of eutectic tin‐lead solder and tin‐silver solder. The resistances of the splices made by ICST were tested at LBNL at liquid helium temperatures over a range of magnetic fields up to 5 T. The breaking strength of 250 mm long splices was also measured at room temperature and liquid nitrogen temperature.
56066198
Power Supply and Quench Protection for the MICE Channel Magnets
LBNL-59004 SCMAG-855 MICE-PUB-GEN-132 Power Supply and Quench Protection for the MICE Channel Magnets* Michael A. Green 1 , and Holger Witte 2 1. Lawrence Berkeley National Laboratory, Berkeley CA 94703, USA 2. Oxford University Physics Department, Oxford OX1-3PU, UK September 2005 Presented at the 2005 European Applied Superconductivity Conference Vienna, Austria 11 through 14 September 2005 * This work was supported by the Oxford University Physics Department and the Particle Physics and Astronomy Research Council of the United Kingdom. This work was also performed at the Lawrence Berkeley National Laboratory with the support of the Office of High Energy Physics, United States Department of Energy under DOE contract DE-AC02- 05CH11231. DOE funding for the US Neutrino Factory and Muon Collider Collaboration is gratefully acknowledged.