9,251 research outputs found
Foreign competition in U.S. banking markets
Foreign penetration of U.S. wholesale banking already exceeds that of most other industry groups; unless market capitalization ratios for U.S. banks go up—or down for foreign banks—this trend is likely to continue.Banks and banking, Foreign - United States
Physics Beyond the Standard Model
I present a brief overview of some exciting possibilities for physics Beyond
the Standard Model. I include short discussions of neutrino physics, the strong
CP problem and axions, GUTs, large and warped extra dimensions, Little Higgs
models and supersymmetry. The chances appear excellent that in the next few
years-- as the LHC era gets underway-- data from a bevy of experiments will
point the way to a new paradigm for the laws of physics as we know them.Comment: 6 pages; to appear in the Proceedings of the Tenth Conference on the
Intersections of Particle and Nuclear Physics (CIPANP 2009), San Diego,
California, 26-31 May, 200
Probing Neutralino Resonance Annihilation via Indirect Detection of Dark Matter
The lightest neutralino of R-parity conserving supersymmetric models serves
as a compelling candidate to account for the presence of cold dark matter in
the universe. In the minimal supergravity (mSUGRA) model, a relic density can
be found in accord with recent WMAP data for large values of the parameter
, where neutralino annihilation in the early universe occurs via the
broad s-channel resonance of the pseudoscalar Higgs boson . We map out rates
for indirect detection of neutralinos via 1. detection of neutrinos arising
from neutralino annihilation in the core of the earth or sun and 2. detection
of gamma rays, antiprotons and positrons arising from neutralino annihilation
in the galactic halo. If indeed -resonance annihilation is the main sink for
neutralinos in the early universe, then signals may occur in the gamma ray,
antiproton and positron channels, while a signal in the neutrino channel would
likely be absent. This is in contrast to the hyperbolic branch/focus point
(HB/FP) region where {\it all} indirect detection signals are likely to occur,
and also in contrast to the stau co-annihilation region, where {\it none} of
the indirect signals are likely to occur.Comment: 12 pages including 4 eps figure
Digital electronic engine control fault detection and accommodation flight evaluation
The capabilities and performance of various fault detection and accommodation (FDA) schemes in existing and projected engine control systems were investigated. Flight tests of the digital electronic engine control (DEEC) in an F-15 aircraft show discrepancies between flight results and predictions based on simulation and altitude testing. The FDA methodology and logic in the DEEC system, and the results of the flight failures which occurred to date are described
Early search for supersymmetric dark matter models at the LHC without missing energy
We investigate early discovery signals for supersymmetry at the Large Hadron
Collider without using information about missing transverse energy. Instead we
use cuts on the number of jets and isolated leptons (electrons and/or muons).
We work with minimal supersymmetric extensions of the standard model, and focus
on phenomenological models that give a relic density of dark matter compatible
with the WMAP measurements. An important model property for early discovery is
the presence of light sleptons, and we find that for an integrated luminosity
of only 200--300 pb at a center-of-mass energy of 10 TeV models with
gluino masses up to GeV can be tested.Comment: 28 pages, 12 figures; published versio
Supersymmetry Reach of Tevatron Upgrades: The Large Case
The Yukawa couplings of the tau lepton and the bottom quark become comparable
to, or even exceed, electroweak gauge couplings for large values of the SUSY
parameter . As a result, the lightest tau slepton \ttau_1 and
bottom squark \tb_1 can be significantly lighter than corresponding sleptons
and squarks of the first two generations. Gluino, chargino and neutralino
decays to third generation particles are significantly enhanced when
is large. This affects projections for collider experiment reach
for supersymmetric particles. In this paper, we evaluate the reach of the
Fermilab Tevatron collider for supersymmetric signals in the
framework of the mSUGRA model. We find that the reach via signatures with
multiple isolated leptons ( and ) is considerably reduced. For very
large , the greatest reach is attained in the multi-jet+\eslt
signature. Some significant extra regions may be probed by requiring the
presence of an identified -jet in jets+\eslt events, or by requiring one
of the identified leptons in clean trilepton events to actually be a hadronic 1
or 3 charged prong tau. In an appendix, we present formulae for chargino,
neutralino and gluino three body decays which are valid at large .Comment: 31 page Revtex file including 10 PS figure
Mixed axion/neutralino cold dark matter in supersymmetric models
We consider supersymmetric (SUSY) models wherein the strong CP problem is
solved by the Peccei-Quinn (PQ) mechanism with a concommitant axion/axino
supermultiplet. We examine R-parity conserving models where the neutralino is
the lightest SUSY particle, so that a mixture of neutralinos and axions serve
as cold dark matter. The mixed axion/neutralino CDM scenario can match the
measured dark matter abundance for SUSY models which typically give too low a
value of the usual thermal neutralino abundance, such as models with wino-like
or higgsino-like dark matter. The usual thermal neutralino abundance can be
greatly enhanced by the decay of thermally-produced axinos to neutralinos,
followed by neutralino re-annihilation at temperatures much lower than
freeze-out. In this case, the relic density is usually neutralino dominated,
and goes as \sim (f_a/N)/m_{axino}^{3/2}. If axino decay occurs before
neutralino freeze-out, then instead the neutralino abundance can be augmented
by relic axions to match the measured abundance. Entropy production from
late-time axino decays can diminish the axion abundance, but ultimately not the
neutralino abundance. In mixed axion/neutralino CDM models, it may be possible
to detect both a WIMP and an axion as dark matter relics. We also discuss
possible modifications of our results due to production and decay of saxions.
In the appendices, we present expressions for the Hubble expansion rate and the
axion and neutralino relic densities in radiation, matter and decaying-particle
dominated universes.Comment: 31 pages including 21 figure
Cost-Benefit Analysis of Climate Change: Stern Revisited
This paper explores the challenges facing orthodox economic approaches to assessing climate control as if it were appraisal of an investment project. Serious flaws are noted in the work of economists with especial attention to the UK Government report by Stern and colleagues. The opinions expressed in this paper are those of the authors and may not be taken to reflect the views CSIRO or the Australian Government.enhanced greenhouse effect, global CBA, Stern Report
Hidden SUSY at the LHC: the light higgsino-world scenario and the role of a lepton collider
While the SUSY flavor, CP and gravitino problems seem to favor a very heavy
spectrum of matter scalars, fine-tuning in the electroweak sector prefers low
values of superpotential mass \mu. In the limit of low \mu, the two lightest
neutralinos and light chargino are higgsino-like. The light charginos and
neutralinos may have large production cross sections at LHC, but since they are
nearly mass degenerate, there is only small energy release in three-body
sparticle decays. Possible dilepton and trilepton signatures are difficult to
observe after mild cuts due to the very soft p_T spectrum of the final state
isolated leptons. Thus, the higgsino-world scenario can easily elude standard
SUSY searches at the LHC. It should motivate experimental searches to focus on
dimuon and trimuon production at the very lowest p_T(\mu) values possible. If
the neutralino relic abundance is enhanced via non-standard cosmological dark
matter production, then there exist excellent prospects for direct or indirect
detection of higgsino-like WIMPs. While the higgsino-world scenario may easily
hide from LHC SUSY searches, a linear e^+e^- collider or a muon collider
operating in the \sqrt{s}\sim 0.5-1 TeV range would be able to easily access
the chargino and neutralino pair production reactions.Comment: 20 pages including 12 .eps figure
Payments system issues in financial markets that never sleep
Payment systems ; Foreign exchange ; Risk ; Stock market
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