14,810 research outputs found
Gauge Transformations, BRST Cohomology and Wigner's Little Group
We discuss the (dual-)gauge transformations and BRST cohomology for the two
(1 + 1)-dimensional (2D) free Abelian one-form and four (3 + 1)-dimensional
(4D) free Abelian 2-form gauge theories by exploiting the (co-)BRST symmetries
(and their corresponding generators) for the Lagrangian densities of these
theories. For the 4D free 2-form gauge theory, we show that the changes on the
antisymmetric polarization tensor e^{\mu\nu} (k) due to (i) the (dual-)gauge
transformations corresponding to the internal symmetry group, and (ii) the
translation subgroup T(2) of the Wigner's little group, are connected with
each-other for the specific relationships among the parameters of these
transformation groups. In the language of BRST cohomology defined w.r.t. the
conserved and nilpotent (co-)BRST charges, the (dual-)gauge transformed states
turn out to be the sum of the original state and the (co-)BRST exact states. We
comment on (i) the quasi-topological nature of the 4D free 2-form gauge theory
from the degrees of freedom count on e^{\mu\nu} (k), and (ii) the Wigner's
little group and the BRST cohomology for the 2D one-form gauge theory {\it
vis-{\`a}-vis} our analysis for the 4D 2-form gauge theory.Comment: LaTeX file, 29 pages, misprints in (3.7), (3.8), (3.9), (3.13) and
(4.14)corrected and communicated to IJMPA as ``Erratum'
Geometrical Aspects Of BRST Cohomology In Augmented Superfield Formalism
In the framework of augmented superfield approach, we provide the geometrical
origin and interpretation for the nilpotent (anti-)BRST charges, (anti-)co-BRST
charges and a non-nilpotent bosonic charge. Together, these local and conserved
charges turn out to be responsible for a clear and cogent definition of the
Hodge decomposition theorem in the quantum Hilbert space of states. The above
charges owe their origin to the de Rham cohomological operators of differential
geometry which are found to be at the heart of some of the key concepts
associated with the interacting gauge theories. For our present review, we
choose the two -dimensional (2D) quantum electrodynamics (QED) as a
prototype field theoretical model to derive all the nilpotent symmetries for
all the fields present in this interacting gauge theory in the framework of
augmented superfield formulation and show that this theory is a {\it unique}
example of an interacting gauge theory which provides a tractable field
theoretical model for the Hodge theory.Comment: LaTeX file, 25 pages, Ref. [49] updated, correct page numbers of the
Journal are give
Wigner's little group and BRST cohomology for one-form Abelian gauge theory
We discuss the (dual-)gauge transformations for the gauge-fixed Lagrangian
density and establish their intimate connection with the translation subgroup
T(2) of the Wigner's little group for the free one-form Abelian gauge theory in
four -dimensions (4D) of spacetime. Though the relationship between
the usual gauge transformation for the Abelian massless gauge field and T(2)
subgroup of the little group is quite well-known, such a connection between the
dual-gauge transformation and the little group is a new observation. The above
connections are further elaborated and demonstrated in the framework of
Becchi-Rouet-Stora-Tyutin (BRST) cohomology defined in the quantum Hilbert
space of states where the Hodge decomposition theorem (HDT) plays a very
decisive role.Comment: LaTeX file, 17 pages, Journal-ref. give
Superfield approach to symmetry invariance in QED with complex scalar fields
We show that the Grassmannian independence of the super Lagrangian density,
expressed in terms of the superfields defined on a (4, 2)-dimensional
supermanifold, is a clear-cut proof for the Becchi-Rouet-Stora-Tyutin (BRST)
and anti-BRST invariance of the corresoponding four (3 + 1)-dimensional (4D)
Lagrangian density that describes the interaction between the U(1) gauge field
and the charged complex scalar fields. The above 4D field theoretical model is
considered on a (4, 2)-dimensional supermanifold parametrized by the ordinary
four spacetime variables x^\mu (with \mu = 0, 1, 2, 3) and a pair of
Grassmannian variables \theta and \bar\theta (with \theta^2 = \bar\theta^2 = 0,
\theta \bar\theta + \bar\theta \theta = 0). Geometrically, the (anti-)BRST
invariance is encoded in the translation of the super Lagrangian density along
the Grassmannian directions of the above supermanifold such that the outcome of
this shift operation is zero.Comment: LaTeX file, 14 pages, minor changes in the title and text, version to
appear in ``Pramana - Journal of Physics'
Cohomological aspects of Abelian gauge theory
We discuss some aspects of cohomological properties of a two-dimensional free
Abelian gauge theory in the framework of BRST formalism. We derive the
conserved and nilpotent BRST- and co-BRST charges and express the Hodge
decomposition theorem in terms of these charges and a conserved bosonic charge
corresponding to the Laplacian operator. It is because of the topological
nature of free U(1) gauge theory that the Laplacian operator goes to zero when
equations of motion are exploited. We derive two sets of topological invariants
which are related to each-other by a certain kind of duality transformation and
express the Lagrangian density of this theory as the sum of terms that are
BRST- and co-BRST invariants. Mathematically, this theory captures together
some of the key features of Witten- and Schwarz type of topological field
theories.Comment: 12 pages, LaTeX, no figures, Title and text have been slightly
changed, Journal reference is given and a reference has been adde
Production of in electron positron collisions
is an atom of simple hydrogenlike structure similar to
positronium and . In this paper energy levels and
decay widths of different decay channels of are given. Cross
section of production of this atomic system in annihilation taking
into account radiative corrections is calculated. According to our estimates
886 atoms may be produced at BEPCII and 29
atoms are produced at VEPP-4M under the present experimental
conditions.Comment: 5 pages, submitted to Int. Jour. Mod. Phys.
DIET COMPOSITION OF ANOA (Buballus sp.) STUDIED USING DIRECT OBSERVATION AND DUNG ANALYSIS METHOD IN THEIR HABITAT
Anoa are fully protected under Indonesian Law since 1931 (Law of Protection of Wild Animals 1931, no
134). Increasing law enforcement regarding hunting as well as promoting awareness of the Anoas unique
threatened the existence of conservation measures. The modern concept of conservation based on the
sustainability utilization, and therefore the knowledge of the Anoa preference in feeding to support the
sustainability conservation should be studied. In the present study, the combination of direct observation
methods which was done in the Lore Lindu National Park in Toro village at District Kulawi, Central Sulawesi
and the epidermal analysis method which was carried out to Anoa’s dung were aimed to identify the vegetations
preferred by Anoa in their habitat. The result showed 28 species of vegetations was used as feed by Anoa
on in situ area. According to its percentage, the first ten were Freycinetia insignis Blume (17%), Microlepia
todayensis Christ (8.9%), Disoxylum sp (8.6%), Lasianthus clementis Merr (7.7%), Clusia sp (7.5%),
Schleria sp (6%), Podocarpus imbricatus (5.4%), Smilax leucophylla (5.1%), Elastostema sp (4.2%),
and Garcinia sp (3.8%), respectively. Furthermore, it can be concluded that Anoa was eat more leafs and
shrubs/bushes (each 24%, respectively) compared to flowers (18%), fruits (12%), shoots (8%), grasses,
tubers, young grooves (each 4%, respectively) and moss (2%). Nutritionally, Anoa consumed 8.8% protein
and 25.6% crude fiber.
Keywords: Diet Composition, Dung Analysis, Ano
Nilpotent Symmetries For Matter Fields In Non-Abelian Gauge Theory: Augmented Superfield Formalism
In the framework of superfield approach to Becchi-Rouet-Stora-Tyutin (BRST)
formalism, the derivation of the (anti-)BRST nilpotent symmetries for the
matter fields, present in any arbitrary interacting gauge theory, has been a
long-standing problem. In our present investigation, the local, covariant,
continuous and off-shell nilpotent (anti-)BRST symmetry transformations for the
Dirac fields are derived in the framework of the augmented
superfield formulation where the four -dimensional (4D) interacting
non-Abelian gauge theory is considered on the six -dimensional
supermanifold parametrized by the four even spacetime coordinates and a
couple of odd elements ( and ) of the Grassmann algebra.
The requirement of the invariance of the matter (super)currents and the
horizontality condition on the (super)manifolds leads to the derivation of the
nilpotent symmetries for the matter fields as well as the gauge- and the
(anti-)ghost fields of the theory in the general scheme of the augmented
superfield formalism.Comment: LaTeX file, 16 pages, printing mistakes in the second paragraph of
`Introduction' corrected, a footnote added, these modifications submitted as
``erratum'' to IJMPA in the final for
- …