1,233 research outputs found
From an automated flight-test management system to a flight-test engineer's workstation
The capabilities and evolution is described of a flight engineer's workstation (called TEST-PLAN) from an automated flight test management system. The concept and capabilities of the automated flight test management systems are explored and discussed to illustrate the value of advanced system prototyping and evolutionary software development
pMSSM Benchmark Models for Snowmass 2013
We present several benchmark points in the phenomenological Minimal
Supersymmetric Standard Model (pMSSM). We select these models as experimentally
well-motivated examples of the MSSM which predict the observed Higgs mass and
dark matter relic density while evading the current LHC searches. We also use
benchmarks to generate spokes in parameter space by scaling the mass parameters
in a manner which keeps the Higgs mass and relic density approximately
constant.Comment: 10 pages, 6 figure
Unique Identification of Graviton Exchange Effects in e^+ e^- Collisions
Many types of new physics can lead to contact interaction-like modifications
in e^+ e^- processes below direct production threshold. We examine the
possibility of uniquely identifying the effects of graviton exchange, which are
anticipated in many extra dimensional theories, from amongst this large set of
models by using the moments of the angular distribution of the final state
particles. In the case of the e^+ e^- --> f bar{f} process we demonstrate that
this technique allows for the unique identification of the graviton exchange
signature at the 5 sigma level for mass scales as high as 6 sqrt(s). The
extension of this method to the e^+ e^- --> W^+ W^- process is also discussed.Comment: 21 pages, 3 figs, LaTe
Signals for Vector Leptoquarks in Hadronic Collisions
We analyze systematically the signatures of vector leptoquarks in hadronic
collisions. We examine their single and pair productions, as well as their
effects on the production of lepton pairs. Our results indicate that a machine
like the CERN Large Hadron Collider (LHC) will be able to unravel the existence
of vector leptoquarks with masses up to the range of -- TeV.Comment: 15 pages and 5 figures (available upon request or through anonymous
ftp), revtex3, IFUSP-P 108
Theory of pixel lensing towards M31 I: the density contribution and mass of MACHOs
POINT-AGAPE is an Anglo-French collaboration which is employing the Isaac
Newton Telescope (INT) to conduct a pixel-lensing survey towards M31. In this
paper we investigate what we can learn from pixel-lensing observables about the
MACHO mass and fractional contribution in M31 and the Galaxy for the case of
spherically-symmetric near-isothermal haloes. We employ detailed pixel-lensing
simulations which include many of the factors which affect the observables. For
a maximum MACHO halo we predict an event rate in V of up to 100 per season for
M31 and 40 per season for the Galaxy. However, the Einstein radius crossing
time is generally not measurable and the observed full-width half-maximum
duration provides only a weak tracer of lens mass. Nonetheless, we find that
the near-far asymmetry in the spatial distribution of M31 MACHOs provides
significant information on their mass and density contribution. We present a
likelihood estimator for measuring the fractional contribution and mass of both
M31 and Galaxy MACHOs which permits an unbiased determination to be made of
MACHO parameters, even from data-sets strongly contaminated by variable stars.
If M31 does not have a significant population of MACHOs in the mass range
0.001-1 Solar masses strong limits will result from the first season of INT
observations. Simulations based on currently favoured density and mass values
indicate that, after three seasons, the M31 MACHO parameters should be
constrained to within a factor four uncertainty in halo fraction and an order
of magnitude uncertainty in mass (90% confidence). Interesting constraints on
Galaxy MACHOs may also be possible. For a campaign lasting ten years,
comparable to the lifetime of current LMC surveys, reliable estimates of MACHO
parameters in both galaxies should be possible. (Abridged)Comment: 21 pages, 14 figures. Submitted to MNRA
Triviality and the (Supersymmetric) See-Saw
For the D=5 Majorana neutrino mass operator to have a see-saw ultraviolet
completion that is viable up to the Planck scale, the see-saw scale is bounded
above due to triviality limits on the see-saw couplings. For supersymmetric
see-saw models, with realistic neutrino mass textures, we compare constraints
on the see-saw scale from triviality bounds, with those arising from
experimental limits on induced charged-lepton flavour violation, for both the
CMSSM and for models with split supersymmetry.Comment: 27 pages, 7 figures, references adde
t-channel production of heavy charged leptons
We study the pair production of heavy charged exotic leptons at e+ e-
colliders in the SU(2)_L x SU(2)_I x U(1)_Y model. This gauge group is a
subgroup of the grand unification group E6; SU(2)_I commutes with the electric
charge operator, and the three corresponding gauge bosons are electrically
neutral. In addition to the standard photon and Z boson contributions, we also
include the contributions from extra neutral gauge bosons. A t-channel
contribution due to W_I-boson exchange, which is unsuppressed by mixing angles,
is quite important. We calculate the left-right and forward-backward
asymmetries, and discuss how to differentiate different models.Comment: Increased discussion of experimental signatures. Version accepted by
PR
Graviton-induced Bremsstrahlung at e^+e^- colliders
We consider graviton-induced Bremsstrahlung at future e^+e^- colliders in
both the ADD and RS models, with emphasis on the photon perpendicular momentum
and angular distribution. The photon spectrum is shown to be harder than in the
Standard Model, and there is an enhancement for photons making large angles
with respect to the beam. In the ADD scenario, the excess at large photon
perpendicular momenta should be measurable for values of the cut-off up to
about twice times the c.m. energy. In the RS scenario, radiative return to
graviton resonances below the c.m. energy can lead to large enhancements of the
cross section.Comment: 23 pages, including figure
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