15942904
Schrödinger-Chern-Simons vortex dynamics
We study the motion of vortices in the planar Ginzburg-Landau model with Schrodinger-Chern-Simons dynamics. We compare the moduli space approximation with the results of numerical simulations of the full field theory and find that there is agreement if the coupling constant is very close to the critical value separating type I from type II superconductors. However, there are significant qualitative differences even for modest deviations from the critically coupled regime. Radiation effects produce forces which are of the same order of magnitude as the intervortex force and therefore have a significant impact on vortex motion. We conclude that the moduli space approximation does not provide a good description of the dynamics in this regime.
119481719
SU(N) Monopoles and Platonic Symmetry
We discuss the ADHMN construction for SU(N) monopoles and show that a particular simplification arises in studying charge N−1 monopoles with minimal symmetry breaking. Using this we construct families of tetrahedrally symmetric SU(4) and SU(5) monopoles. In the moduli space approximation, the SU(4) one-parameter family describes a novel dynamics where the monopoles never separate, but rather, a tetrahedron deforms to its dual. We find a two-parameter family of SU(5) tetrahedral monopoles and compute some geodesics in this submanifold numerically. The dynamics is rich, with the monopoles scattering either once or twice through octahedrally symmetric configurations.
14764118
A monopole metric
We calculate explicitly in terms of complete elliptic integrals the metric on the moduli space of tetrahedrally-symmetric, charge four, SU(2) monopoles. Using this we verify that in the asymptotic regime the metric of Gibbons and Manton is exact up to exponentially suppressed corrections.
9022461
Rational Maps, Monopoles and Skyrmions
We discuss the similarities between BPS monopoles and Skyrmions, and point to an underlying connection in terms of rational maps between Riemann spheres. This involves the introduction of a new ansatz for Skyrme fields. We use this to construct good approximations to several known Skyrmions, including all the minimal energy configurations up to baryon number nine, and some new solutions such as a baryon number seventeen Skyrme field with the truncated icosahedron structure of a buckyball. The new approach is also used to understand the low-lying vibrational modes of Skyrmions, which are required for quantization. Along the way we discover an interesting Morse function on the space of rational maps which may be of use in understanding the Sen forms on the monopole moduli spaces.
53065799
Hyperbolic vortices with large magnetic flux
There has been some recent interest in the study of non-Abelian Bogomolny-Prasad-Sommerfield (BPS) monopoles in the limit of large magnetic charge. Most investigations have used a magnetic bag approximation, in which spherical symmetry is assumed within an Abelian description. In particular, this approach has been used to suggest the existence of two types of magnetic bags, with differing distributions of the zeros of the Higgs field, together with multilayer structures, containing several magnetic bags. This paper is concerned with the analogous situation of Abelian BPS vortices in the hyperbolic plane, in the limit of large magnetic flux. This system has the advantage that explicit exact solutions can be obtained and compared with a magnetic bag approximation. Exact BPS vortex solutions are presented that are analogous to the two types of magnetic bags predicted for BPS monopoles and it is shown that these structures can be combined to produce exact multilayer solutions.
18365450
Instantons and the buckyball
The study of Skyrmions predicts that there is an icosahedrally symmetric charge 17 SU(2) Yang–Mills instanton in which the topological charge density, for fixed Euclidean time, is localized on the edges of the truncated icosahedron of the buckyball. In this paper the existence of such an instanton is proved by explicit construction of the associated ADHM data. A topological charge density isosurface is displayed which verifies the buckyball structure of the instanton.
18410762
DEVELOPMENT OF A POSITRON PRODUCTION TARGET FOR THE ILC POSITRON SOURCE
The future International Linear Collider (ILC) will require of order 10 14 positrons per second to fulfil its luminosity requirements. The current baseline design produces this unprecedented flux of positrons using an undulatorbased source. In this concept, a collimated beam of photons produced from the action of an undulator on the main electron beam of the ILC is incident on a conversiontarget. Positrons producedin the resulting electromagneticshower can then be captured, accelerated and injected into a damping ring. The positron source community is pursuing several alternative technologies to develop a target capable of long-term operation in the intense photon beam. In the design being developed jointly by Lawrence Livermore National Laboratory (LLNL), Stanford Linear Accelerator Center (SLAC), the University of Liverpool and the Cockcroft Institute a thin (0.4 radiation length) watercooled titanium alloy target wheel of diameter 2 m is rotated at approximately 1000 rpm to spread the incident power of each pulse over a wide area. We review the role of the target in the positron source and present the latest target design.
53410002
A double-sided silicon micro-strip Super-Module for the ATLAS Inner Detector upgrade in the High-Luminosity LHC
The ATLAS experiment is a general purpose detector aiming to fully exploit the discovery potential of the Large Hadron Collider (LHC) at CERN. It is foreseen that after several years of successful data-taking, the LHC physics programme will be extended in the so-called High-Luminosity LHC, where the instantaneous luminosity will be increased up to 5 × 1034 cm−2 s−1. For ATLAS, an upgrade scenario will imply the complete replacement of its internal tracker, as the existing detector will not provide the required performance due to the cumulated radiation damage and the increase in the detector occupancy. The current baseline layout for the new ATLAS tracker is an all-silicon-based detector, with pixel sensors in the inner layers and silicon micro-strip detectors at intermediate and outer radii. The super-module is an integration concept proposed for the strip region of the future ATLAS tracker, where double-sided stereo silicon micro-strip modules are assembled into a low-mass local support structure. An electrical super-module prototype for eight double-sided strip modules has been constructed. The aim is to exercise the multi-module readout chain and to investigate the noise performance of such a system. In this paper, the main components of the current super-module prototype are described and its electrical performance is presented in detail.
53461882
A double-sided, shield-less stave prototype for the ATLAS Upgrade strip tracker for the High Luminosity LHC
A detailed description of the integration structures for the barrel region of the silicon strips tracker of the ATLAS Phase-II upgrade for the upgrade of the Large Hadron Collider, the so-called High Luminosity LHC (HL-LHC), is presented. This paper focuses on one of the latest demonstrator prototypes recently assembled, with numerous unique features. It consists of a shortened, shield-less, and double sided stave, with two candidate power distributions implemented. Thermal and electrical performances of the prototype are presented, as well as a description of the assembly procedures and tools.