1,118 research outputs found
Higher Spin BRS Cohomology of Supersymmetric Chiral Matter in D=4
We examine the BRS cohomology of chiral matter in , supersymmetry
to determine a general form of composite superfield operators which can suffer
from supersymmetry anomalies. Composite superfield operators \Y_{(a,b)} are
products of the elementary chiral superfields and \ov S and the
derivative operators D_\a, \ov D_{\dot \b} and \pa_{\a \dot \b}. Such
superfields \Y_{(a,b)} can be chosen to have `' symmetrized undotted
indices \a_i and `' symmetrized dotted indices \dot \b_j. The result
derived here is that each composite superfield \Y_{(a,b)} is subject to
potential supersymmetry anomalies if is an odd number, which means that
\Y_{(a,b)} is a fermionic superfield.Comment: 15 pages, CPT-TAMU-20/9
BRS Operators and Covariant Derivatives in Loop Space for P-Branes Coupled to Yang-Mills
Canonical forms are given for the nilpotent BRS operator \d and the
covariant `loop space' derivative {\cal D}_{\m} for the p-brane fields for
all odd p. The defining characteristic of {\cal D}_{\m} is that it is a
functional derivative operator which generalizes the ordinary functional
derivative and also commutes with \d. Methods of construction for the
canonical forms are discussed.Comment: 21 pages, CTP-TAMU-50/9
BRS Cohomology of the Supertranslations in D=4
Supersymmetry transformations are a kind of square root of spacetime
translations. The corresponding Lie superalgebra always contains the
supertranslation operator . We find that the
cohomology of this operator depends on a spin-orbit coupling in an SU(2) group
and has a quite complicated structure. This spin-orbit type coupling will turn
out to be basic in the cohomology of supersymmetric field theories in general.Comment: 14 pages, CTP-TAMU-13/9
Localized Tachyons and the g_cl conjecture
We consider C/Z_N and C^2/Z_N orbifolds of heterotic string theories and Z_N
orbifolds of AdS_3. We study theories with N=2 worldsheet superconformal
invariance and construct RG flows. Following Harvey, Kutasov, Martinec and
Moore, we compute g_cl and show that it decreases monotonically along RG flows-
as conjectured by them. For the heterotic string theories, the gauge degrees of
freedom do not contribute to the computation of g_cl.Comment: Corrections and clarifications made, 19 page
The Coupling of Yang-Mills to Extended Objects
The coupling of Yang-Mills fields to the heterotic string in bosonic
formulation is generalized to extended objects of higher dimension (p-branes).
For odd p, the Bianchi identities obeyed by the field strengths of the
(p+1)-forms receive Chern-Simons corrections which, in the case of the 5-brane,
are consistent with an earlier conjecture based on string/5-brane duality.Comment: 14 Page
Fitting the Quark and Lepton Masses in String Theories
The capability of string theories to reproduce at low energy the observed
pattern of quark and lepton masses and mixing angles is examined, focusing the
attention on orbifold constructions, where the magnitude of Yukawa couplings
depends on the values of the deformation parameters which describe the size and
shape of the compactified space. A systematic exploration shows that for ,
, --I and possibly orbifolds a correct fit of the physical
fermion masses is feasible. In this way the experimental masses, which are
low--energy quantities, select a particular size and shape of the compactified
space, which turns out to be very reasonable (in particular the modulus
defining the former is ). The rest of the orbifolds are rather
hopeless and should be discarded on the assumption of a minimal scenario. On the other hand, due to stringy selection
rules, there is no possibility of fitting the Kobayashi--Maskawa parameters at
the renormalizable level, although it is remarked that this job might well be
done by non--renormalizable couplings.Comment: 19 page
Soft SUSY Breaking Terms in Stringy Scenarios: Computation and Phenomenological Viability
We calculate the soft SUSY breaking terms arising from a large class of
string scenarios, namely symmetric orbifold constructions, and study its
phenomenological viability. They exhibit a certain lack of universality, unlike
the usual assumptions of the minimal supersymmetric standard model. Assuming
gaugino condensation in the hidden sector as the source of SUSY breaking, it
turns out that squark and slepton masses tend to be much larger than gaugino
masses. Furthermore, we show that these soft breaking terms can be perfectly
consistent with both experimental and naturalness constraints (the latter comes
from the absence of fine tuning in the breaking process). This is certainly non--trivial and in fact
imposes interesting constraints on measurable quantities. More precisely, we
find that the gluino mass () and the chargino mass ()
cannot be much higher than their present experimental lower bounds
(GeV ; $M_{\chi^\pm}\stackrel{<}{{}_\sim}80\
\stackrel{>}{{}_\sim} 1\ 80\
\stackrel{<}{{}_\sim}m_t\stackrel{<}{{}_\sim}165\ $GeV)Comment: 18 pages, CERN-TH.6681/9
Pembelajaran Menulis Karangan Narasi Menggunakan Pemetaan Alur Pikir Siswa SMAN 9 Kota Kupang
This study refers to the low interest of students in writing narrative essays, students prefer to work on the questions in the Student Worksheet (LKS) compared to writing assignments, learning to write essays, especially teacher narrative essays only explain the material and assign students to write essays freely without guidance from the teacher, in writing narrative essays students struggle to arrange essays chronologically. In fact, writing learning itself has been applied in schools, especially in Class X2 students of SMA Negeri 9 Kupang City, but there are still many students who do not understand how to write essays, especially writing narrative essays. Based on that the solution applied is the researchers chose to use the Mind Mapping model which aims to explore information from both inside and outside the brain in order to obtain new ideas, new concepts according to students' understanding and prove the effectiveness of learning to write narrative essays. This research uses Pre Experimental in the form of Pretest-Posttest Design. The research data were obtained from observations, questionnaires, test results and field notes. The results showed that in the pretest, the average value of students was 51.73 or less categorized. The scores on the pretest have not yet reached the KKM that has been set. While the posttest increased by 29.63 or 57.27% to 81.36 and was in the good category. The expected benefit of this research is the development of educational theory theory, specifically the problem of the effectiveness of mind-mapping technique to develop students' writing potential, can improve and provide a more varied choice of learning techniques in the learning process and can create a fun learning activity, to improve skills student writing
Chern-Simons forms, Mickelsson-Faddeev algebras and the p-branes
In string theory, nilpotence of the BRS operator \d for the string
functional relates the Chern-Simons term in the gauge-invariant antisymmetric
tensor field strength to the central term in the Kac-Moody algebra. We
generalize these ideas to p-branes with odd p and find that the Kac-Moody
algebra for the string becomes the Mickelsson-Faddeev algebra for the p-brane.Comment: 11 pages, CTP-TAMU-45-92, (Correction of some minor sign errors and
typos
Threshold Corrections and Gauge Symmetry in Twisted Superstring Models
Threshold corrections to the running of gauge couplings are calculated for
superstring models with free complex world sheet fermions. For two N=1
models, the threshold corrections lead to a small increase
in the unification scale. Examples are given to illustrate how a given particle
spectrum can be described by models with different boundary conditions on the
internal fermions. We also discuss how complex twisted fermions can enhance the
symmetry group of an N=4 model to the gauge group
. It is then shown how a mixing angle analogous
to the Weinberg angle depends on the boundary conditions of the internal
fermions.Comment: easier to Tex version, figures to be sent separatel
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