12,544 research outputs found
The CP-violating pMSSM at the Intensity Frontier
In this Snowmass whitepaper, we describe the impact of ongoing and proposed
intensity frontier experiments on the parameter space of the Minimally
Supersymmetric Standard Model (MSSM). We extend a set of phenomenological MSSM
(pMSSM) models to include non-zero CP-violating phases and study the
sensitivity of various flavor observables in these scenarios Future electric
dipole moment and rare meson decay experiments can have a strong impact on the
viability of these models that is relatively independent of the detailed
superpartner spectrum. In particular, we find that these experiments have the
potential to probe models that are expected to escape searches at the
high-luminosity LHC.Comment: 10 pages, 2 figures. Contributed to the Community Summer Study 2013,
Minneapolis, MN July 29 - August 6, 201
Quasiequilibrium sequences of black-hole--neutron-star binaries in general relativity
We construct quasiequilibrium sequences of black hole-neutron star binaries
for arbitrary mass ratios by solving the constraint equations of general
relativity in the conformal thin-sandwich decomposition. We model the neutron
star as a stationary polytrope satisfying the relativistic equations of
hydrodynamics, and account for the black hole by imposing equilibrium boundary
conditions on the surface of an excised sphere (the apparent horizon). In this
paper we focus on irrotational configurations, meaning that both the neutron
star and the black hole are approximately nonspinning in an inertial frame. We
present results for a binary with polytropic index n=1, mass ratio
M_{irr}^{BH}/M_{B}^{NS}=5 and neutron star compaction
M_{ADM,0}^{NS}/R_0=0.0879, where M_{irr}^{BH} is the irreducible mass of the
black hole, M_{B}^{NS} the neutron star baryon rest-mass, and M_{ADM,0}^{NS}
and R_0 the neutron star Arnowitt-Deser-Misner mass and areal radius in
isolation, respectively. Our models represent valid solutions to Einstein's
constraint equations and may therefore be employed as initial data for
dynamical simulations of black hole-neutron star binaries.Comment: 5 pages, 1 figure, revtex4, published in Phys.Rev.
Towards W b bbar + j at NLO with an automatized approach to one-loop computations
We present results for the O(alpha_s) virtual corrections to q g -> W b bbar
q' obtained with a new automatized approach to the evaluation of one-loop
amplitudes in terms of Feynman diagrams. Together with the O(alpha_s)
corrections to q q' -> W b bbar g, which can be obtained from our results by
crossing symmetry, this represents the bulk of the next-to-leading order
virtual QCD corrections to W b bbar + j and W b + j hadronic production,
calculated in a fixed-flavor scheme with four light flavors. Furthermore, these
corrections represent a well defined and independent subset of the 1-loop
amplitudes needed for the NNLO calculation of W b bbar. Our approach was tested
against several existing results for NLO amplitudes including selected
O(alpha_s) one-loop corrections to W + 3 j hadronic production. We discuss the
efficiency of our method both with respect to evaluation time and numerical
stability.Comment: 14 pages, 3 figure
From field to plate - How do bacterial enteric pathogens interact with ready-to-eat fruit and vegetables, causing disease outbreaks?
Ready-to-eat fruit and vegetables are a convenient source of nutrients and fibre for consumers, and are generally safe to eat, but are vulnerable to contamination with human enteric bacterial pathogens. Over the last decade, Salmonella spp., pathogenic Escherichia coli, and Listeria monocytogenes have been linked to most of the bacterial outbreaks of foodborne illness associated with fresh produce. The origins of these outbreaks have been traced to multiple sources of contamination from pre-harvest (soil, seeds, irrigation water, domestic and wild animal faecal matter) or post-harvest operations (storage, preparation and packaging). These pathogens have developed multiple processes for successful attachment, survival and colonization conferring them the ability to adapt to multiple environments. However, these processes differ across bacterial strains from the same species, and across different plant species or cultivars. In a competitive environment, additional risk factors are the plant microbiome phyllosphere and the plant responses; both factors directly modulate the survival of the pathogens on the leaf's surface. Understanding the mechanisms involved in bacterial attachment to, colonization of, and proliferation, on fresh produce and the role of the plant in resisting bacterial contamination is therefore crucial to reducing future outbreaks
Gauge Field Formulation of Adiabatic Spin Torques
Previous calculation of spin torques for small-amplitude magnetization
dynamics around a uniformly magnetized state [J. Phys. Soc. Jpn. {\bf 75}
(2006) 113706] is extended here to the case of finite-amplitude dynamics. This
is achieved by introducing an `` adiabatic'' spin frame for conduction
electrons, and the associated SU(2) gauge field. In particular, the Gilbert
damping is shown to arise from the time variation of the spin-relaxation source
terms in this new frame, giving a new physical picture of the damping. The
present method will allow a `` first-principle'' derivation of spin torques
without any assumptions such as rotational symmetry in spin space.Comment: 4 pages, 3 figure
Initial Helioseismic Observations by Hinode/SOT
Results from initial helioseismic observations by Solar Optical Telescope
onboard Hinode are reported. It has been demonstrated that intensity
oscillation data from Broadband Filter Imager can be used for various
helioseismic analyses. The k-omega power spectra, as well as corresponding
time-distance cross-correlation function that promises high-resolution
time-distance analysis below 6-Mm travelling distance, were obtained for G-band
and CaII-H data. Subsurface supergranular patterns have been observed from our
first time-distance analysis. The results show that the solar oscillation
spectrum is extended to much higher frequencies and wavenumbers, and the
time-distance diagram is extended to much shorter travel distances and times
than they were observed before, thus revealing great potential for
high-resolution helioseismic observations from Hinode.Comment: 6 pages, accepted for publication in PAS
Ariel - Volume 4 Number 6
Editors
David A. Jacoby
Eugenia Miller
Tom Williams
Associate Editors
Paul Bialas
Terry Burt
Michael Leo
Gail Tenikat
Editor Emeritus and Business Manager
Richard J. Bonnano
Movie Editor
Robert Breckenridge
Staff
Richard Blutstein
Mary F. Buechler
J.D. Kanofsky
Rocket Weber
David Maye
La organización de la información, los lenguajes documentales y la normalización
La calidad de la información que se maneja actualmente ha aumentado debido a las nuevas tecnologías. Esta comunicación se plantea la calidad de la información que los bibliotecarios ofrecen a sus usuarios a través de diversas herramientas : control de autoridades, normalización, normas bibliográficas, lenguajes documentales y encabezamientos de materia
Moments of the Virtual Photon Structure Function
The photon structure function is a useful testing ground for QCD. It is
perturbatively computable apart from a contribution from what is usually called
the hadronic component of the photon. There have been many proposals for this
nonperturbative part of the real photon structure function. By studying moments
of the virtual photon structure function, we explore the extent to which these
proposed nonperturbative contributions can be identified experimentally.Comment: LaTeX, 16 pages + 14 compressed and uuencoded postscript figures,
UMN-TH-1111/9
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