34616942
Unification of forces and particles in superstring theories
Superstring field theories have emerged as potentially consistent quantum field theories that unify gravity with the other fundamental forces in an almost unique manner. They are based on the dynamics of string-like fundamental quanta rather than the point-like quanta of more familiar relativistic ‘point field theories’ such as Yang-Mills gauge theory or general relativity. In these theories the observed fundamental particles, such as the leptons and quarks, may arise as the ground states of a string. This amounts to a profound generalization of the conventional field theory framework.
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.
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.
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.
36002879
Computer Simulation of the Interaction of a Superconducting Synchrotron Magnet Good Field Region with a Particle Beam
This paper illustrates how the results of several magnetic field calculation computer programs can be combined to form a single graphical representation of magnetic field quality within the aperture of a superconducting accelerator magnet. The graphical technique can be applied on a magnet by magnet basis over a range of current excitations. The paper illustrates the value of such graphics when the accelerator beam profile is shown within the simulated magnet bore.
136567622
Ferromagnetic Material in the Superconductor and Its Effect on the Magnetization Sextupole and Decapole in the SSC Dipoles at Injection
It has been shown that the magnetization of a multi-filamentary superconductor can be altered by adding nickel to the composite strand. This report presents the results of calculations of the magnetization sextupole and higher multipoles in a 5 cm Superconducting Super Collider (SSC) dipole with and without nickel as part of the strand composite. The relative distribution of the nickel in the inner and outer coil conductors can be used to effectively eliminate sextupole and decapole at the SSC dipole injection field. Calculations of magnetization sextupole in the dipole are presented for strand with substituted nickel filaments and strand with electroplated nickel. The effect of nickel in the strand on the SSC dipole field quality at fields above the injection field is described. The effect of nickel in the strand on magnetization sextupole flux creep decay and the magnetization sextupole temperature dependence is also discussed.
111271489
QUENCH BACK IN SUPERCONDUCTING MAGNETS WITH SHORTED SECONDARY CIRCUITS
While testing a thin superconducting solenoid with a shorted secondary circuit, the coil was observed to become fully normal faster than quench propagation would permit. We call this process “quench back”. The quench back was caused by heating in the secondary circuit from current induced from the primary circuit. This paper presents a theoretical expression which can be used to estimate the quench back time in a solenoid with a well coupled secondary circuit. The calculation of quench back time is compared with measurements made on two one-meter diameter solenoid magnets.
117704564
Superconducting RF Cavities and Magnets for a 4-TeV Energy Muon Collider
The accelerators must take the muon beams from {approximately} 100 MeV to 2 TeV energies within the muon lifetime for a 4 TeV energy muon collider. These constraints plus the muon decay heating seriously challenge the designs of the superconducting RF (SRF) cavities and magnets in the accelerators and collider ring. The multiple superconducting recirculation linac and the very rap8id-cycling superconducting synchrotron approach are both studied. The authors briefly introduce the technical considerations and preliminary designs of the SRF systems and magnets.
118834673
A Design for a Combined Function Superconducting Dipole for a Muon Collider FFAG Accelerator
The acceleration stages for a muon collider require that the muons be accelerated within a given ring in fewer than twenty turns. One type of accelerator that appears to be attractive for a synchrotron that accelerates the muon a factor of four in energy in a few turns is the Fixed Field Alternating Gradient (FFAG) type of accelerator. As the energy of the muon beam increases, the muons move toward a higher field region of a DC combined function dipole. The following dipole and quadrupole magnet characteristics are required for a muon FFAG machine to be successful: (1) The dipole will be a fixed field dipole with an impressed quadrupole and sextupole field. There may or may not be separate quadrupoles that mayor may not have added sextupole windings. (2) The horizontal aperture of the required good field region is wider than the vertical aperture of the required good field region. (3) The magnet is relatively short, so that the conventional SSC type of superconducting dipole or quadrupole ends can not be used. The field at the end of the magnet must fall off abruptly within the distance of less than one vertical aperture. For a magnet that is 400more » mm long, the end region can be no more than 80 mm long. (4) The structure of the integrated field within the end region must be the same as the structure of the two-dimensional filed at the center of the magnet. A very preliminary design concept for a FFAG combined function dipole is presented in this paper.« less