相关论文: High Energy Particles from Monopoles Connected by …
Superstring theory and other supersymmetric theories predict the existence of relatively light, weakly interacting scalar particles, called moduli, with a universal form of coupling to matter. Such particles can be emitted from cusps of…
The electromagnetic decay and final annihilation of magnetic monopole-antimonopole pairs formed in the early universe has been proposed as a possible mechanism to produce the highest energy cosmic rays. We show that for a monopole abundance…
We study massive particle radiation from cosmic string kinks, and its observability in extremely high energy neutrinos. In particular, we consider the emission of moduli --- weakly coupled scalar particles predicted in supersymmetric…
Quantum electrodynamics predicts that in a strong electric field, electron-positron pairs are produced by the Schwinger process, which can be interpreted as quantum tunnelling through the Coulomb potential barrier. If magnetic monopoles…
It is shown that bulk acceleration during reconnection of extremely strong magnetic fields near compact objects can accelerate ions to Lorentz factors of $\sim 10^2 \sigma^{3/5}$ under general conditions, where $\sigma$, the magnetic energy…
Monopole-antimonopole pairs connected by strings can be formed as topological defects in a sequence of cosmological phase transitions. Such hybrid defects typically decay early in the history of the universe but can still generate an…
It is difficult for conventional sources to accelerate cosmic ray particles to the highest energies that have been observed. Topological defects such as monopoles and strings overcome this difficulty, because their natural energy scale is…
Cosmic rays with energies exceeding $10^{20}\eV$ have been detected. The origin of these highest energy cosmic rays remains unknown. Established astrophysical acceleration mechanisms encounter severe difficulties in accelerating particles…
Cosmic strings are a type of cosmic defect formed by a symmetry-breaking phase transition in the early universe. Individual strings would have gathered to build a network, and their dynamical motion would induce scalar--, vector-- and…
Topological defects, particularly cosmic strings, can provide a mechanism to produce particles with energies of the order 10^21 eV and higher. Here, we report on order of magnitude calculations of fluxes from a cosmic string network which…
We discuss the possibility of observing ultra high energy cosmic ray sources inhigh energy gamma rays. Protons propagating away from their accelerators produce secondary electrons during interactions with cosmic microwave background…
In this paper we investigate the theory behind the results in [11]. In [11] we calculated the magnetic dipole moment of the muon and the electric dipole moments of the muon, electron and the neutron (in a simple quark model) to first order…
Superconducting cosmic strings naturally emit highly boosted charge carriers from cusps. This occurs when a cosmic string or a loop moves through a magnetic field and develops an electric current. The charge carriers and the products of…
Ultra-high energy (UHE) photons above 10^{18} eV serve as valuable probes of fundamental physics. While typically produced in interactions involving charged particles, they could also originate from exotic sources such as annihilations of…
We investigate the role of massless magnetic monopoles in the N=4 supersymmetric Yang-Mills Higgs theories. They can appear naturally in the 1/4-BPS dyonic configurations associated with multi-pronged string configurations. Massless…
The spherically symmetric magnetic monopole in an SU(2) gauge theory coupled to a massless Higgs field is shown to possess an infinite number of resonances or quasinormal modes. These modes are eigenfunctions of the isospin 1 perturbation…
The spontaneous breaking of $SO(10)$ via flipped $SU(5)$ to the Standard Model yields a novel scenario in which the superheavy topologically stable GUT monopole carrying a single unit ($2\pi/e$) of Dirac magnetic charge emerges from the…
The topological defect scenario of origin of the observed highest energy cosmic rays is reviewed. Under a variety of circumstances, topological defects formed in the early Universe can be sources of very massive particles in the Universe…
Magnetic monopoles, if they exist, would be produced amply in strong magnetic fields and high temperatures via the thermal Schwinger process. Such circumstances arise in heavy ion collisions and in neutron stars, both of which imply lower…
A strong laser field and the Coulomb field of a nucleus can produce e^{+}e^{-} pairs. It is shown for the first time that there is a large probability that electrons and positrons created in this process collide after one or several…