19,255 research outputs found
(Anti-)chiral Superfield Approach to Nilpotent Symmetries: Self-Dual Chiral Bosonic Theory
We exploit the beauty and strength of the symmetry invariant restrictions on
the (anti-)chiral superfields to derive the Becchi-Rouet-Stora-Tyutin (BRST),
anti-BRST and (anti-)co-BRST symmetry transformations in the case of a two
(1+1)-dimensional (2D) self-dual chiral bosonic field theory within the
framework of augmented (anti-)chiral superfield formalism. Our 2D ordinary
theory is generalized onto a (2, 2)-dimensional supermanifold which is
parameterized by the superspace variable Z^M = (x^\mu, \theta, \bar\theta)
where x^\mu (with \mu = 0, 1) are the ordinary 2D bosonic coordinates and
(\theta,\, \bar\theta) are a pair of Grassmannian variables with their standard
relationships: \theta^2 = {\bar\theta}^2 =0, \theta\,\bar\theta +
\bar\theta\theta = 0. We impose the (anti-)BRST and (anti-)co-BRST invariant
restrictions on the (anti-)chiral superfields (defined on the (anti-)chiral (2,
1)-dimensional super-submanifolds of the above general (2, 2)-dimensional
supermanifold) to derive the above nilpotent symmetries. We do not exploit the
mathematical strength of the (dual-)horizontality conditions anywhere in our
present investigation. We also discuss the properties of nilpotency, absolute
anticommutativity and (anti-)BRST and (anti-)co-BRST symmetry invariance of the
Lagrangian density within the framework of our augmented (anti-)chiral
superfield formalism. Our observation of the absolute anticommutativity
property is a completely novel result in view of the fact that we have
considered only the (anti-)chiral superfields in our present endeavor.Comment: LaTeX file, 20 pages, journal reference is give
Abelian 2-form gauge theory: superfield formalism
We derive the off-shell nilpotent Becchi-Rouet-Stora-Tyutin (BRST) and
anti-BRST symmetry transformations for {\it all} the fields of a free Abelian
2-form gauge theory by exploiting the geometrical superfield approach to BRST
formalism. The above four (3 + 1)-dimensional (4D) theory is considered on a
(4, 2)-dimensional supermanifold parameterized by the four even spacetime
variables x^\mu (with \mu = 0, 1, 2, 3) and a pair of odd Grassmannian
variables \theta and \bar\theta (with \theta^2 = \bar\theta^2 = 0, \theta
\bar\theta + \bar\theta \theta = 0). One of the salient features of our present
investigation is that the above nilpotent (anti-)BRST symmetry transformations
turn out to be absolutely anticommuting due to the presence of a Curci-Ferrari
(CF) type of restriction. The latter condition emerges due to the application
of our present superfield formalism. The actual CF condition, as is well-known,
is the hallmark of a 4D non-Abelian 1-form gauge theory. We demonstrate that
our present 4D Abelian 2-form gauge theory imbibes some of the key signatures
of the 4D non-Abelian 1-form gauge theory. We briefly comment on the
generalization of our supperfield approach to the case of Abelian 3-form gauge
theory in four (3 + 1)-dimensions of spacetime.Comment: LaTeX file, 23 pages, journal versio
An Alternative To The Horizontality Condition In Superfield Approach To BRST Symmetries
We provide an alternative to the gauge covariant horizontality condition
which is responsible for the derivation of the nilpotent (anti-)BRST symmetry
transformations for the gauge and (anti-)ghost fields of a (3 + 1)-dimensional
(4D) interacting 1-form non-Abelian gauge theory in the framework of the usual
superfield approach to Becchi-Rouet-Stora-Tyutin (BRST) formalism. The above
covariant horizontality condition is replaced by a gauge invariant restriction
on the (4, 2)-dimensional supermanifold, parameterized by a set of four
spacetime coordinates x^\mu (\mu = 0, 1, 2, 3) and a pair of Grassmannian
variables \theta and \bar\theta. The latter condition enables us to derive the
nilpotent (anti-)BRST symmetry transformations for all the fields of an
interacting 4D 1-form non-Abelian gauge theory where there is an explicit
coupling between the gauge field and the Dirac fields. The key differences and
striking similarities between the above two conditions are pointed out clearly.Comment: LaTeX file, 20 pages, journal versio
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
The Wear Project
When we meet a character in a performance, the implicit understanding is that they have existed until the point where we join their journey and will continue existing after we leave them. Their clothing tells a story to the audience before any words are spoken and before any action takes place. As a Costume Designer and Lecturer, my awareness of costuming as an anthropological practice has led me to explore these principles using myself as the subject of scrutiny. For one year I am logging every clothing combination I go through along with memories, prices, locations and dates etc. in order to explore the clothing decisions I make and the stories, embedded in my clothes, that I am surrounded by every day. What does my wardrobe mean to me inwardly and reveal outwardly to others? How does this 'me-search' extend my artistic practice? The Wear Project will be a visual archive, a teaching tool, and a foundation for further academic research/writing through the questions it raises about design, visual storytelling, memory, dress and audience: a personal interrogation generating a critical framework for understanding the dramaturgical significance of costume. I welcome any interest, suggestions, questions, provocations, conversations or counter- projects that could lead my research, costume design or performance related teaching in general into unexplored areas. The Wear Project is available for anybody to view or use on flickr at http://bit.ly/1kAYv74
Pedagogies applied to develop student self-awareness and written self-evaluations: a costume case study
In 2013–14 a change in assessment criteria percentage weightings on the BA Stage Management and Technical Theatre course at East 15 Acting School was implemented – a course taught mainly through authentic learning processes. This change, coupled with the increase in emphasis on reflective processes in higher education in general, highlighted that students not only on this course but also more widely need to be able to articulate their learning more rigorously than before through more comprehensively written self-evaluations. Through a discussion of critical thinking and reflection and instinctively applying Art and Design pedagogies to teaching on what is traditionally considered to be a vocational course, this article charts an experimental case study following students on the Costume Pathway, hoping to improve their ability in this area. The aim was to develop the self-awareness and analytical and reflective thinking involved in evaluating personal working practices to a high standard in order to improve the written communication thereof. Therefore, this article is also a reflection on how a thorough understanding from educators of what self-evaluation demands of students can enrich student learning experiences and develop transferable skills to produce industry-ready and life-ready graduates
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.
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