SEARCH · Engineering Papers
Results for “MONOPOLES”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Search for magnetic monopoles and stable particles with high electric charges in 8 TeV p p collisions with the ATLAS detector
Not Available
A non-Abelian SO(8) monopole as generalization of Dirac-Yang monopoles for a 9-dimensional space
We establish an explicit form of a non-Abelian SO(8) monopole in a 9-dimensional space and show that it is indeed a direct generalization of Dirac and Yang monopoles. Using the generalized Hurwitz transformation, we have found a connection between a 16-dimensional harmonic oscillator and a 9-dimensional hydrogenlike atom in the field of the SO(8) monopole (MICZ-Kepler problem). Using the built connection the group of dynamical symmetry of the 9-dimensional MICZ-Kepler problem is found as SO(10, 2).
Search for Magnetic Monopoles and Stable High-Electric-Charge Objects in 13 Tev Proton-Proton Collisions with the ATLAS Detector
Explore the source record for details and available documents.
Propagation of magnetic charge monopoles and Dirac flux strings in an artificial spin-ice lattice
Not Available
Emergence of low-energy monopole strength in the neutron-rich calcium isotopes
Not Available
Effective model of QCD magnetic monopoles from numerical study of one- and two-component Coulomb quantum Bose gases
Not Available
Search for Magnetic Monopoles in root s=7 TeV pp Collisions with the ATLAS Detector
.
Search for Magnetic Monopoles with the NO$\nu$A Far Detector
The magnetic monopole is a hypothetical particle, which is an important field configuration in many Grand Unified Theories, and whose mass may vary from 10 4 to 10 18 GeV. The quantization of magnetic charge derived by Dirac in 1931 suggests the heavy ionization nature of magnetic monopoles. The NO$\nu$A collaboration is using the NO$\nu$A far detector - the largest scintillator detector in the world - to search for signals of relic monopoles that might have been produced in the early universe. To achieve this, we have simulated the propagation of non-relativistic monopoles with a uniform distribution of velocity within the range 10 -4 ≲β≲ 0.2 , and the corresponding detector response. To record potential monopole-like events, we have developed a data-driven trigger system with two monopole triggers (the fast monopole trigger and the slow monopole trigger). This analysis focuses on the data recorded by the fast monopole trigger, which is sensitive to monopoles with velocity β ≳ 10 -3 . We have performed a blind analysis on a total live time of 1628.2 hours of data recorded by the fast monopole trigger. We present the updated flux limits with 90% CL (confidence level) as a function of monopole mass and velocity.
The one and a half monopoles solution of the SU(2) Yang–Mills–Higgs field theory
Recently we have reported on the existence of finite energy SU(2) Yang–Mills–Higgs particle of one-half topological charge. In this paper, we show that this one-half monopole can co-exist with a ’t Hooft–Polyakov monopole. The magnetic charge of the one-half monopole is of opposite sign to the magnetic charge of the ’t Hooft–Polyakov monopole. However the net magnetic charge of the configuration is zero due to the presence of a semi-infinite Dirac string along the positive z-axis that carries the other half of the magnetic monopole charge. The solution possesses gauge potentials that are singular along the z-axis, elsewhere they are regular. The total energy is found to increase with the strength of the Higgs field self-coupling constant λ. However the dipole separation and the magnetic dipole moment decrease with λ. This solution is non-BPS even in the BPS limit when the Higgs self-coupling constant vanishes. -- Highlights: •This one-half monopole can co-exist with a ’t Hooft–Polyakov monopole. •The magnetic charge of the one-half monopole and one monopole is of opposite sign. •This solution is non-BPS. •The net magnetic charge of the configuration is zero. •This solution upon Cho decomposition is only singular along the negative z-axis.
Designing phase sensitive probes of monopole superconducting order
Distinct from familiar s-, p-, or d-wave pairings, the monopole superconducting order represents a novel class of pairing order arising from nontrivial monopole charge of the Cooper pair. In the weak-coupling regime, this order can emerge when pairing occurs between Fermi surfaces with different Chern numbers in, for example, doped Weyl semimetal systems. However, the phase of monopole pairing order is not well-defined over an entire Fermi surface, making it challenging to design experiments sensitive to both its symmetry and topology. To address this, we propose a scheme based on symmetry and topological principles to identify this elusive pairing order through a set of phase-sensitive Josephson experiments. By examining the discrepancy between global and local angular momentum of the pairing order, we can unveil the monopole charge of the pairing order, including for models with higher pair monopole charge |q p |=1,2, and 3. We demonstrate the proposed probe of monopole pairing order through analytic and numerical studies of Josephson coupling in models of monopole superconductor junctions. This work opens a promising avenue to uncover the unique topological properties of monopole pairing orders and to distinguish them from known pairing orders based on spherical harmonic symmetry.
Measuring global monopole velocities, one by one
We present an estimation of the average velocity of a network of global monopoles in a cosmological setting using large numerical simulations. In order to obtain the value of the velocity, we improve some already known methods, and present a new one. This new method estimates individual global monopole velocities in a network, by means of detecting each monopole position in the lattice and following the path described by each one of them. Using our new estimate we can settle an open question previously posed in the literature: velocity-dependent one-scale (VOS) models for global monopoles predict two branches of scaling solutions, one with monopoles moving at subluminal speeds and one with monopoles moving at luminal speeds. Previous attempts to estimate monopole velocities had large uncertainties and were not able to settle that question. Our simulations find no evidence of a luminal branch. We also estimate the values of the parameters of the VOS model. With our new method we can also study the microphysics of the complicated dynamics of individual monopoles. Finally we use our large simulation volume to compare the results from the different estimator methods, as well as to asses the validity of the numerical approximations made.
High pressure route to generate magnetic monopole dimers in spin ice
The gas of magnetic monopoles in spin ice is governed by one key parameter: the monopole chemical potential. A significant variation of this parameter could access hitherto undiscovered magnetic phenomena arising from monopole correlations, as observed in the analogous electrical Coulomb gas, like monopole dimerization, critical phase separation, or charge ordering. However, all known spin ices have values of chemical potential imposed by their structure and chemistry that place them deeply within the weakly correlated regime, where none of these interesting phenomena occur. Here we use high-pressure synthesis to create a new monopole host, Dy 2 Ge 2 O 7 , with a radically altered chemical potential that stabilizes a large fraction of monopole dimers. The system is found to be ideally described by the classic Debye–Huckel–Bjerrum theory of charge correlations. We thus show how to tune the monopole chemical potential in spin ice and how to access the diverse collective properties of magnetic monopoles.
Elastic colloidal monopoles and reconfigurable self-assembly in liquid crystals
Monopole-like electrostatic interactions are ubiquitous in condensed matter, but they are often screened by counter-ions and cannot be switched from attractive to repulsive. In colloidal science, where the main goal is to develop colloidal particles that mimic and exceed the diversity and length scales of atomic and molecular assembly, electrostatically charged particles cannot change the sign of their surface charge or transform from monopoles to higher-order multipoles. In liquid-crystal colloids, elastic interactions between particles arise to minimize the free energy associated with elastic distortions in the long-range alignment of rod-like molecules around the particles. In dipolar quadrupolar and hexadecapolar nematic colloids, the symmetries of such elastic distortions mimic both electrostatic multipoles and the outermost occupied electron shells of atoms. Electric and magnetic switching, spontaneous transformations and optical control of elastic multipoles, as well as their interactions with topological defects and surface boundary conditions, have been demonstrated in such colloids. However, it has long been understood that elastic monopoles should relax to uniform or higher-order multipole states because of the elastic torques that they induce. We develop nematic colloids with strong elastic monopole moments and with elastic torques balanced by the optical torques induced by ambient light. We demonstrate the monopole-to-quadrupole reconfiguration of these colloidal particles by unstructured light, which resembles the driving of atoms between the ground state and various excited states. We show that the sign of the elastic monopoles can be switched, and that like-charged monopoles attract whereas oppositely charged ones repel, unlike in electrostatics. We also demonstrate the out-of-equilibrium dynamic assembly of these colloidal particles. This diverse and surprising behaviour is explained using a model that considers the balance of the optical and elastic torques that are responsible for the excited-state elastic monopoles and may lead to light-powered active-matter systems and self-assembled nanomachines.
Monopoles, strings, and necklaces in SO(10) and E 6
We employ a variety of symmetry breaking patterns in SO(10) and E 6 Grand Unified Theories to demonstrate the appearance of topological defects including magnetic monopoles, strings, and necklaces. We show that independent of the symmetry breaking pattern, a topologically stable superheavy monopole carrying a single unit of Dirac charge as well as color magnetic charge is always present. Lighter intermediate mass topologically stable monopoles carrying two or three quanta of Dirac charge can appear in SO(10) and E 6 models respectively. These lighter monopoles as well as topologically stable intermediate scale strings can survive an inflationary epoch. We also show the appearance of a novel necklace configuration in SO(10) broken to the Standard Model via SU(4) c × SU(2) L × SU(2) R . It consists of SU(4) c and SU(2) R monopoles connected by flux tubes. Necklaces consisting of monopoles and antimonopoles joined together by flux tubes are also identified. Even in the absence of topologically stable strings, a monopole-string system can temporarily appear. This system decays by emitting gravity waves and we provide an example in which the spectrum of these waves is strongly peaked around 10 –4 Hz with Ω qw h 2 ≃10 –12 . This spectrum should be within the detection capability of LISA.
Search for Slow Magnetic Monopoles with the NOνA Far Detector
The magnetic monopole is a hypothetical particle with a magnetic charge. It is an important field configuration in many Grand Unified Theories. Dirac in 1931 derived a charge quantization condition, which suggests that the existence of one magnetic monopole in the universe will explain electric charge quantization. Since then, a search of the elusive particle has begun, and yet all came with negative results. The NO$\nu$A Far Detector is able to probe some of the parameter space for the search for monopoles. To achieve this, two dedicated triggers, one for fast monopoles and the other for slow monopoles, have been developed to record signals. Results for the first 8 months of high-gain slow monopole data were obtained, and a 90\% CL limit was established with no monopole observed. The analysis in this thesis is focused on new data with a higher gain, and we have explored potential improvement in efficiency and improvements in the reconstruction algorithm. We have done this an alysis on Monte-Carlo generated simulated data to establish efficiencies and examined a control set of the new data to understand its differences from the old.