46 research outputs found
Study of Bose-Einstein Correlations in e+e- -> W+W- events at LEP
Bose-Einstein correlation between like-sign charged-particle pairs in e+e- ->
W+W- events recorded with the OPAL detector at LEP at centre-of-mass energies
between 183 GeV and 209 GeV are studied. Recently proposed methods which allow
direct searches for correlations in the data via distributions of test
variables are used to investigate the presence of correlations between hadrons
originating from different W bosons in W+W- -> qqqq events. Within the
statistics of the data sample no evidence for inter-WW Bose-Einstein
correlations is obtained. The data are also compared with predictions of a
recent implementation of Bose-Einstein correlation effects in the Monte Carlo
model PYTHIA.Comment: 29 pages, 10 figures, Submitted to Eur. Phys. J.
New solution of the Supersymmetric KdV equation via Hirota methods
We consider the resolution of the supersymmetric KdV equation
with () from the Hirota formalism. For the first time, a
bilinear form of the equation is constructed. We construct
multisoliton solutions and rational similarity solutions.Comment: 7 pages, 9 figures. arXiv admin note: significant text overlap with
arXiv:1104.059
Form invariance symmetry generates a large set of FRW cosmologies
We show that Einstein's field equations for spatially flat
Friedmann-Robertson-Walker (FRW) space times have a form invariance symmetry
(FIS) realized by the form invariance transformations (FIT) which are indeed
generated by an invertible function of the source energy density. These
transformations act on the Hubble expansion rate, the energy density, and
pressure of the cosmic fluid; likewise such transformations are endowed with a
Lie group structure. Each representation of this group is associated with a
particular fluid and consequently a determined cosmology, so that, the FIS
defines a set of equivalent cosmological models. We focus our seek in the FIT
generated by a linear function because it provides a natural framework to
express the duality and also produces a large sets of cosmologies, starting
from a seed one, in several contexts as for instance in the cases of a perfect
fluid source and a scalar field driven by a potential depending linearly on the
scalar field kinetic energy density.Comment: 11 pages, 3 figures. Accepted for publication in Modern Physics
Letters A (2012
Are N=1 and N=2 supersymmetric quantum mechanics equivalent?
After recalling different formulations of the definition of supersymmetric
quantum mechanics given in the literature, we discuss the relationships between
them in order to provide an answer to the question raised in the title.Comment: 15 page
Twisted Superspace for N=D=2 Super BF and Yang-Mills with Dirac-K\"ahler Fermion Mechanism
We propose a twisted D=N=2 superspace formalism. The relation between the
twisted super charges including the BRST charge, vector and pseudo scalar super
charges and the N=2 spinor super charges is established. We claim that this
relation is essentially related with the Dirac-K\"ahler fermion mechanism. We
show that a fermionic bilinear form of twisted N=2 chiral and anti-chiral
superfields is equivalent to the quantized version of BF theory with the Landau
type gauge fixing while a bosonic bilinear form leads to the N=2 Wess-Zumino
action. We then construct a Yang-Mills action described by the twisted N=2
chiral and vector superfields, and show that the action is equivalent to the
twisted version of the D=N=2 super Yang-Mills action, previously obtained from
the quantized generalized topological Yang-Mills action with instanton gauge
fixing.Comment: 36 page
W-algebras from symplectomorphisms
It is shown how -algebras emerge from very peculiar canonical
transformations with respect to the canonical symplectic structure on a compact
Riemann surface. The action of smooth diffeomorphisms of the cotangent bundle
on suitable generating functions is written in the BRS framework while a
-symmetry is exhibited. Subsequently, the complex structure of the symmetry
spaces is studied and the related BRS properties are discussed. The specific
example of the so-called -algebra is treated in relation to some other
different approaches.Comment: LaTex, 25 pages, no figures, to appear in Journ. Math. Phy
Symmetries of topological field theories in the BV-framework
Topological field theories of Schwarz-type generally admit symmetries whose
algebra does not close off-shell, e.g. the basic symmetries of BF models or
vector supersymmetry of the gauge-fixed action for Chern-Simons theory (this
symmetry being at the origin of the perturbative finiteness of the theory). We
present a detailed discussion of all these symmetries within the algebraic
approach to the Batalin-Vilkovisky formalism. Moreover, we discuss the general
algebraic construction of topological models of both Schwarz- and Witten-type.Comment: 30 page
The role of complex structures in w-symmetry
In a symplectic framework, the infinitesimal action of symplectomorphisms
together with suitable reparametrizations of the two dimensional complex base
space generate some type of W-algebras. It turns out that complex structures
parametrized by Beltrami differentials play an important role in this context.
The construction parallels very closely two dimensional Lagrangian conformal
models where Beltrami differentials are fundamental.Comment: LaTex, 34 pages, no figures, to be published in Nucl. Phys.
A Generalization of Slavnov-Extended Non-Commutative Gauge Theories
We consider a non-commutative U(1) gauge theory in 4 dimensions with a
modified Slavnov term which looks similar to the 3-dimensional BF model. In
choosing a space-like axial gauge fixing we find a new vector supersymmetry
which is used to show that the model is free of UV/IR mixing problems, just as
in the previously discussed model in arXiv:hep-th/0604154. Finally, we present
generalizations of our proposed model to higher dimensions.Comment: 25 pages, no figures; v2 minor correction
Supersymmetry in quantum mechanics: An extended view
The concept of supersymmetry in a quantum mechanical system is extended,
permitting the recognition of many more supersymmetric systems, including very
familiar ones such as the free particle. Its spectrum is shown to be
supersymmetric, with space-time symmetries used for the explicit construction.
No fermionic or Grassmann variables need to be invoked. Our construction
extends supersymmetry to continuous spectra. Most notably, while the free
particle in one dimension has generally been regarded as having a doubly
degenerate continuum throughout, the construction clarifies taht there is a
single zero energy state at the base of the spectrum.Comment: 4 pages, 4 figure