2,097 research outputs found
Non-standard Dirac adjoint spinor: The emergence of a new dual
In this present communication we provide a new derivation of the Dirac dual
structure by employing a different approach from the originally proposed.
Following a general and rigorous mathematical process to compute the dual
structure, we investigate if is possible to break the existing "rigidity" in
its primordial formulation. For this task, firstly, we look towards to
understand the core of the Dirac spinors construction and then, we suggest to
built an alternative dual structure for the Dirac spinor, which preserve an
invariant norm under any transformation. Finally, we verify
if the prominent physical contents are maintained or if it is affected by such
construction.Comment: 7 pages, 0 figure
Limits on a Strong Electroweak Sector from e^+ e^- -> 2gamma + missing E at LEP2
We study the process in the context
of a strong electroweak symmetry breaking model, which can be a source of
events with two photons and missing energy at LEP2. We investigate bounds on
the model assuming that no deviation is observed from the Standard Model within
a given experimental error.Comment: 7 pages, Latex, one figur
A new signature for color octet pseudoscalars at the LHC
Color octet (pseudo)scalars, if they exist, will be copiously produced at the
CERN Large Hadron Collider (LHC). However, their detection can become a very
challenging task. In particular, if their decay into a pair of top quarks is
kinematically forbidden, the main decay channel would be into two jets, with a
very large background. In this Brief Report we explore the possibility of using
anomaly-induced decays of the color octet pseudoscalars into gauge bosons to
find them at the LHC.Comment: 4 pages, 2 figures. New references adde
Effective lagrangian for a mass dimension one fermionic field in curved spacetime
In this work we use momentum-space techniques to evaluate the propagator
for a spin mass dimension one spinor field on a curved
Friedmann-Robertson-Walker spacetime. As a consequence, we built the one-loop
correction to the effective lagrangian in the coincidence limit. Going further
we compute the effective lagrangian in the finite temperature regime. We arrive
at interesting cosmological consequences, as time-dependent cosmological
`constant', fully explaining the functional form of previous cosmological
models.Comment: 9 pages, 0 figure
Gauge Invariance, Color-Octet Vector Resonances and Double Technieta Production at the Tevatron
We show that the usual vector meson dominance method does not apply directly
to the mixing of a color-octet vector boson (color-octet technirho) with the
gluon because of gauge invariance. We propose a gauge invariant method where
one works in a physical basis with mass eigenstate fields. As a result, we show
that the physical technirho does not couple to two gluons, contrary to the
general belief. Consequences for the production of a pair of color-octet,
isosinglet technipions (technietas) at Fermilab is analysed by means of a
simulation of the signal and background, including kinematical cuts. We find
that the signal is too small to be observed.Comment: 14 page
STRONGLY COUPLED ELECTROWEAK SYMMETRY BREAKING: IMPLICATIONS OF MODELS
We discuss the phenomenology of models of dynamical electroweak symmetry
breaking which attempt to generate the observed fermion mass spectrum. After
briefly describing the variety of and constraints on proposed models, we
concentrate on the signatures of colored pseudo-Nambu-Goldstone bosons and
resonances at existing and proposed colliders. These particles provide a
possibly unique signature: strongly produced resonances associated with
electroweak symmetry breaking. (This is the subgroup report for the
``Electroweak Symmetry Breaking and Beyond the Standard Model" working group of
the DPF Long Range Planning Study. This report will appear as a chapter in
``Electroweak Symmetry Breaking and Beyond the Standard Model", edited by T.
Barklow, S. Dawson, H.E. Haber, and J. Siegrist, to be published by World
Scientific.
On the Spinor Representation
A systematic study of the spinor representation by means of the fermionic
physical space is accomplished and implemented. The spinor representation space
is shown to be constrained by the Fierz-Pauli-Kofink identities among the
spinor bilinear covariants. A robust geometric and topological structure can be
manifested from the spinor space, wherein, for instance, the first and second
homotopy groups play prominent roles on the underlying physical properties,
associated to the fermionic fields.Comment: 16 page
An alternative approach concerning Elko spinors and the hidden unitarity
In this theoretical communication we look towards understand the underlying
phenomenology concerning the Elko spinors within VSR theory. The program to be
accomplished here start when we define the eigenspinors of the charge
conjugation operator as eigenstates of the helicity operator in the Cartesian
coordinates system. This prescription is very useful in the sense of
phenomenological point of view, so, we propose a set of Elko spinors ready to
be computationally implemented. Regardless of, in order to show the application
of given approach we impose to these spinors to be restrict to an axis,
coincidentally the axis of locality, and then, using the proposed prescription,
we search for physical amounts and physical processes by analysing the Yukawa
and the self-interaction in such framework.Comment: 10 pages, 2 figures. Accepted for publication in AAC
Outflows, Inflows and Young Stars in the inner 200 pc of the Seyfert galaxy NGC 2110
We present a two-dimensional mapping of stellar population age components,
emission-line fluxes, gas excitation and kinematics within the inner
pc of the Seyfert 2 galaxy NGC 2110. We used the Gemini North Integral Field
Spectrograph (NIFS) in the J and K bands at a spatial resolution of
pc. The unresolved nuclear continuum is originated in combined contributions of
young stellar population (SP; age Myr), a featureless AGN continuum
and hot dust emission. The young-intermediate SP (age Myr) is
distributed in a ring-shaped structure at pc from the nucleus,
which is roughly coincident with the lowest values of the stellar velocity
dispersion. In the inner pc the old SP (age Gyr) is dominant.
The [FeII]1.25m emission-line flux distribution is correlated with the
radio emission and its kinematics comprise two components, one from gas
rotating in the galaxy plane and another from gas in outflow within a bicone
oriented along north-south. These outflows seem to originate in the interaction
of the radio jet with the ambient gas producing shocks that are the main
excitation mechanism of the [FeII] emission. We estimate: (1) an ionized gas
mass outflow rate of M/yr at 70 pc from the nucleus;
and (2) a kinetic power for the outflow of only 0.05% of the AGN bolometric
luminosity implying weak feedback effect on the galaxy.Comment: Accepted for publication in MNRA
- …
