35,909 research outputs found
Short-scale break-up in unsteady interactive layers: Local development of normal pressure gradients and vortex wind-up
Following the finite-time collapse of an unsteady interacting boundary layer (step 1), shortened length and time scales are examined here in the near-wall dynamics of transitional-turbulent boundary layers or during dynamic stall. The next two steps are described, in which (step 2) normal pressure gradients come into operation along with a continuing nonlinear critical-layer jump and then (step 3) vortex formation is induced typically. Normal pressure gradients enter in at least two ways, depending on the internal or external flow configuration. This yields for certain internal flows an extended KdV equation with an extra nonlinear integral contribution multiplied by a coefficient which is proportional to the normal rate of change of curvature of the velocity profile locally and whose sign turns out to be crucial. Positive values of the coefficient lead to a further finite-time singularity, while negative values produce a rapid secondary instability phenomenon. Zero values in contrast allow an interplay between solitary waves and wave packets to emerge at large scaled times, this interplay eventually returning the flow to its original, longer, interactive, boundary-layer scales but now coupled with multiple shorter-scale Euler regions. In external or quasi-external flows more generally an extended Benjamin–Ono equation holds instead, leading to a reversal in the roles of positive and negative values of the coefficient. The next step, 3, typically involves the strong wind-up of a local vortex, leading on to explosion or implosion of the vortex. Further discussion is also presented, including the three-dimensional setting, the computational implications, and experimental links
A 125.5 GeV Higgs Boson in F-SU(5): Imminently Observable Proton Decay, A 130 GeV Gamma-ray Line, and SUSY Multijets & Light Stops at the LHC8
We establish that the light Higgs boson mass in the context of the No-Scale
Flipped SU(5) GUT with TeV scale vector-like matter multiplets (flippons) is
consistent with m_h = 125.5+-0.5 GeV in the region of the best supersymmetry
(SUSY) spectrum fit to low statistics data excesses observed by ATLAS in
multijet and light stop 5/fb SUSY searches at the LHC7. Simultaneous
satisfaction of these disparate goals is achieved by employing a minor decrease
in the SU(5) partial unification scale M_{32} to lower the flippon mass,
inducing a larger Higgs boson mass shift from the flippon loops. The reduction
in M_{32}, which is facilitated by a phenomenologically favorable reduction of
the low-energy strong coupling constant, moreover suggests an imminently
observable (e|mu)^+ pi^0 proton decay with a central value time scale of
1.7x10^34 years. At the same point in the model space, we find a lightest
neutralino mass of m_{\chi} = 145 GeV, which is suitable for the production of
130 GeV monochromatic gamma-rays through annihilations yielding associated
Z-bosons; a signal with this energy signature has been identified within
observations of the galactic center by the FERMI-LAT Space Telescope. In
conjunction with direct correlations to the fate of the ATLAS multijet and
light stop production channels presently being tested at the LHC8, we suggest
that the reality of a 125.5 GeV Higgs boson affords a particularly rich company
of specific and imminently testable associated observables.Comment: European Physical Journal C Version; 10 Pages, 2 Figures, 2 Table
Non-trivial Supersymmetry Correlations between ATLAS and CMS Observations
We present definite correlations between the CMS 5 \fb all-hadronic search
employing the stransverse mass variable and the ATLAS 5 \fb
all-hadronic and multijet supersymmetry (SUSY) searches, suggesting the
possibility that both the ATLAS and CMS experiments are already registering a
faint but legitimate SUSY signal at the LHC. We isolate this prospective mutual
productivity beyond the Standard Model in the framework of the supersymmetric
No-Scale Flipped (5) grand unified theory, supplemented with extra
vector-like matter (flippons). Evident overproduction is observed in three CMS
\mt2 and four ATLAS hadronic and multijet signal regions, where a \x2 fitting
procedure of the CMS 5 \fb \mt2 search establishes a best fit SUSY mass in
sharp agreement with corresponding ATLAS searches of equivalently heightened
signal significance. We believe this correlated behavior across two distinct
experiments at precisely the same SUSY mass scale to be highly non-trivial, and
potentially indicative of an existing 5 \fb LHC reach into a pervasive physical
supersymmetry framework.Comment: 6 Pages, 2 Figure
Profumo di SUSY: Suggestive Correlations in the ATLAS and CMS High Jet Multiplicity Data
We present persistently amassing evidence that the CMS and ATLAS
Collaborations may indeed be already registering supersymmetry events at the
Large Hadron Collider (LHC). Our analysis is performed in the context of a
highly phenomenologically favorable model named No-Scale F-SU(5), which
represents the unification of the F-lipped SU(5) Grand Unified Theory (GUT),
two pairs of hypothetical TeV-scale vector-like supersymmetric multiplets
derived out of F-Theory, and the dynamically established boundary conditions of
No-Scale supergravity. We document highly suggestive correlations between the
first inverse femtobarn of observations by CMS and ATLAS, where seductive
excesses in multijet events, particularly those with nine or more jets, are
unambiguously accounted for by a precision Monte-Carlo simulation of the
F-SU(5) model space. This intimate correspondence is optimized by a unified
gaugino mass in the neighborhood of M_{1/2}=518 GeV. We supplement this
analysis by extrapolating for the expected data profile to be realized with
five inverse femtobarns of integrated luminosity, as expected to be observed at
the LHC by the conclusion of 2011. Significantly, we find that this luminosity
may be sufficient to constitute a SUSY discovery for the favored benchmark
spectrum. Indeed, the winds wafting our way from Geneva may already be heavy
with the delicate perfume of Supersymmetry.Comment: 15 pages, 5 figures, 6 table
Dark Matter, Proton Decay and Other Phenomenological Constraints in -SU(5)
We study gravity mediated supersymmetry breaking in -SU(5) and its
low-energy supersymmetric phenomenology. The gaugino masses are not unified at
the traditional grand unification scale, but we nonetheless have the same
one-loop gaugino mass relation at the electroweak scale as minimal supergravity
(mSUGRA). We introduce parameters testable at the colliders to measure the
small second loop deviation from the mSUGRA gaugino mass relation at the
electroweak scale. In the minimal SU(5) model with gravity mediated
supersymmetry breaking, we show that the deviations from the mSUGRA gaugino
mass relations are within 5%. However, in -SU(5), we predict the
deviations from the mSUGRA gaugino mass relations to be larger due to the
presence of vector-like particles, which can be tested at the colliders. We
determine the viable parameter space that satisfies all the latest experimental
constraints and find it is consistent with the CDMS II experiment. Further, we
compute the cross-sections of neutralino annihilations into gamma-rays and
compare to the first published Fermi-LAT measurement. Finally, the
corresponding range of proton lifetime predictions is calculated and found to
be within reach of the future Hyper-Kamiokande and DUSEL experiments.Comment: Nuclear Physics B Versio
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