12,700 research outputs found
II. The Standard Model in the Isotopic Foldy-Wouthuysen Representation without Higgs Bosons in the Fermion Sector. Spontaneous Breaking of Parity and "Dark Matter" Problems
The Standard Model with massive fermions is formulated in the isotopic
Foldy-Wouthuysen representation. SU(2)xU(1) - invariance of the theory in this
representation is independent of whether fermions possess mass or not, and,
consequently, it is not necessary to introduce interactions between Higgs
bosons and fermions. The study discusses a possible relation between
spontaneous breaking of parity in the isotopic Foldy-Wouthuysen representation
and the composition of elementary particles of "dark matter".Comment: 12 page
The resultant parameters of effective theory
This is the 4-th paper in the series devoted to a systematic study of the
problem of mathematically correct formulation of the rules needed to manage an
effective field theory. Here we consider the problem of constructing the full
set of essential parameters in the case of the most general effective
scattering theory containing no massless particles with spin J > 1/2. We
perform the detailed classification of combinations of the Hamiltonian coupling
constants and select those which appear in the expressions for renormalized
S-matrix elements at a given loop order.Comment: 21 pages, 4 LaTeX figures, submitted to Phys. Rev.
The topological structure of SU(2) gluodynamics at T > 0 : an analysis using the Symanzik action and Neuberger overlap fermions
We study SU(2) gluodynamics at finite temperature on both sides of the
deconfining phase transition. We create the lattice ensembles using the
tree-level tadpole-improved Symanzik action. The Neuberger overlap Dirac
operator is used to determine the following three aspects of vacuum structure:
(i) The topological susceptibility is evaluated at various temperatures across
the phase transition, (ii) the overlap fermion spectral density is determined
and found to depend on the Polyakov loop above the phase transition and (iii)
the corresponding localization properties of low-lying eigenmodes are
investigated. Finally, we compare with zero temperature results.Comment: 20 pages, 21 figures, one new figure, two overloaded figures split in
two, minor clarifying changes throughout the text, final version accepted by
Physical Review
Ultraviolet Divergences in Cosmological Correlations
A method is developed for dealing with ultraviolet divergences in
calculations of cosmological correlations, which does not depend on dimensional
regularization. An extended version of the WKB approximation is used to analyze
the divergences in these calculations, and these divergences are controlled by
the introduction of Pauli--Villars regulator fields. This approach is
illustrated in the theory of a scalar field with arbitrary self-interactions in
a fixed flat-space Robertson--Walker metric with arbitrary scale factor .
Explicit formulas are given for the counterterms needed to cancel all
dependence on the regulator properties, and an explicit prescription is given
for calculating finite regulator-independent correlation functions. The
possibility of infrared divergences in this theory is briefly considered.Comment: References added on various regularization methods. Improved
discussion of further issues. 26 pages, 1 figur
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