30,098 research outputs found
Gravitationally Coupled Electroweak Monopole
We present a family of gravitationally coupled electroweak monopole solutions
in Einstein-Weinberg-Salam theory. Our result confirms the existence of
globally regular gravitating electroweak monopole which changes to the
magnetically charged black hole as the Higgs vacuum value approaches to the
Planck scale. Moreover, our solutions could provide a more accurate description
of the monopole stars and magnetically charged black holes
Finite Energy Electroweak Dyon
The recent MoEDAL experiment at LHC to detect the electroweak monopole makes
the theoretical prediction of the monopole mass an urgent issue. We discuss
different ways to estimate the mass of the electroweak monopole. We first
present a scaling argument which indicates that the mass of the electroweak
monopole to be around 4 TeV. To justify this we construct finite energy
analytic dyon solutions which could be viewed as the regularized Cho-Maison
dyon, modifying the coupling strengths of the electromagnetic interaction of
-boson in the standard model. Our result demonstrates that a genuine
electroweak monopole whose mass scale is much smaller than the grand
unification scale can exist, which can actually be detected at the present LHC.Comment: arXiv admin note: substantial text overlap with arXiv:hep-th/0210299,
arXiv:hep-th/970703
Quasilinear approach of the cumulative whistler instability in fast solar winds: Constraints of electron temperature anisotropy
Context. Solar outflows are a considerable source of free energy which
accumulates in multiple forms like beaming (or drifting) components and/or
temperature anisotropies. However, kinetic anisotropies of plasma particles do
not grow indefinitely and particle-particle collisions are not efficient enough
to explain the observed limits of these anisotropies. Instead, the
self-generated wave instabilities can efficiently act to constrain kinetic
anisotropies, but the existing approaches are simplified and do not provide
satisfactory explanations. Thus, small deviations from isotropy shown by the
electron temperature () in fast solar winds are not explained yet.
Aims. This paper provides an advanced quasilinear description of the whistler
instability driven by the anisotropic electrons in conditions typical for the
fast solar winds. The enhanced whistler-like fluctuations may constrain the
upper limits of temperature anisotropy ,
where are defined with respect to the magnetic field
direction.
Methods. Studied are the self-generated whistler instabilities, cumulatively
driven by the temperature anisotropy and the relative (counter)drift of the
electron populations, e.g., core and halo electrons. Recent studies have shown
that quasi-stable states are not bounded by the linear instability thresholds
but an extended quasilinear approach is necessary to describe them in this
case.
Results. Marginal conditions of stability are obtained from a quasilinear
theory of the cumulative whistler instability, and approach the quasi-stable
states of electron populations reported by the observations.The instability
saturation is determined by the relaxation of both the temperature anisotropy
and the relative drift of electron populations.Comment: Accepted for publication in A&
Elastic Cross Sections for Electron Collisions with Molecules Relevant to Plasma Processing
Absolute electron-impact cross sections for molecular targets, including their radicals, are important in developing plasma reactors and testing various plasma processing gases. Low-energy electron collision data for these gases are sparse and only the limited cross section data are available. In this report, elastic cross sections for electron-polyatomic molecule collisions are compiled and reviewed for 17molecules relevant to plasma processing. Elastic cross sections are essential for the absolute scale conversion of inelastic cross sections, as well as for testing computational methods. Data are collected and reviewed for elastic differential, integral, and momentum transfer cross sections and, for each molecule, the recommended values of the cross section are presented. The literature has been surveyed through early 2010.This work is accomplished as a collaboration through APAN (Asia-Pacific Atomic Data Network: a network for dissemination of collisional data relevant to plasmas, discharges, materials, and biosciences). H.C. acknowledges a support by the National Research Foundation of Korea (Grant No. 20100000035), and M.J.B. and S.J.B. support from the Australian Research Council Center of Excellence for Antimatter-Matter Studies. Collaboration between NIFS and NFRI is also acknowledged for the Korea-Japan exchanges
- …