340 research outputs found
On a gauge-invariant deformation of a classical gauge-invariant theory
We consider a general gauge theory with independent generators and study the
problem of gauge-invariant deformation of initial gauge-invariant classical
action. The problem is formulated in terms of BV-formalism and is reduced to
describing the general solution to the classical master equation. We show that
such general solution is determined by two arbitrary generating functions of
the initial fields. As a result, we construct in explicit form the deformed
action and the deformed gauge generators in terms of above functions. We argue
that the deformed theory must in general be non-local. The developed
deformation procedure is applied to Abelian vector field theory and we show
that it allows to derive non-Abelain Yang-Mills theory. This procedure is also
applied to free massless integer higher spin field theory and leads to local
cubic interaction vertex for such fields.Comment: 15 pages.v2: minor corrections, published versio
BRST-BV quantization of gauge theories with global symmetries
We consider the general gauge theory with a closed irreducible gauge algebra
possessing the non-anomalous global (super)symmetry in the case when the gauge
fixing procedure violates the global invariance of classical action. The theory
is quantized in the framework of BRST-BV approach in the form of functional
integral over all fields of the configuration space. It is shown that the
global symmetry transformations are deformed in the process of quantization and
the full quantum action is invariant under such deformed global transformations
in the configuration space. The deformed global transformations are calculated
in an explicit form in the one-loop approximation.Comment: 16 pages, v2: references adde
UV continuum emission and diagnostics of hydrogen-containing non-equilibrium plasmas
For the first time the emission of the radiative dissociation continuum of
the hydrogen molecule ( electronic
transition) is proposed to be used as a source of information for the
spectroscopic diagnostics of non-equilibrium plasmas. The detailed analysis of
excitation-deactivation kinetics, rate constants of various collisional and
radiative transitions and fitting procedures made it possible to develop two
new methods of diagnostics of: (1) the ground state
vibrational temperature from the relative intensity
distribution, and (2) the rate of electron impact dissociation
(d[\mbox{H_{2}}]/dt)_{\text{diss}} from the absolute intensity of the
continuum. A known method of determination of from relative
intensities of Fulcher- bands was seriously corrected and simplified
due to the revision of transition probabilities and cross sections of
electron impact excitation. General considerations are illustrated
with examples of experiments in pure hydrogen capillary-arc and H+Ar
microwave discharges.Comment: REVTeX, 25 pages + 12 figures + 9 tables. Phys. Rev. E, eprint
replaced because of resubmission to journal after referee's 2nd repor
BRST structure of non-linear superalgebras
In this paper we analyse the structure of the BRST charge of nonlinear
superalgebras. We consider quadratic non-linear superalgebras where a
commutator (in terms of (super) Poisson brackets) of the generators is a
quadratic polynomial of the generators. We find the explicit form of the BRST
charge up to cubic order in Faddeev-Popov ghost fields for arbitrary quadratic
nonlinear superalgebras. We point out the existence of constraints on structure
constants of the superalgebra when the nilpotent BRST charge is quadratic in
Faddeev-Popov ghost fields. The general results are illustrated by simple
examples of superalgebras.Comment: 15 pages, Latex, references added, misprints corrected, comments
adde
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