6,124 research outputs found
Higgs Properties and BSM Higgs Boson Searches at the LHC
At the end of 2008, the Large Hadron Collider (LHC) will come into operation and the two experiments ATLAS and CMS will start taking data from proton-proton collisions at a center-of-mass energy of sqrt{s}=14 TeV. In preparation for the data taking period, the discovery potential for Higgs bosons beyond the Standard Model has been updated by both experiments and is reviewed here. In addition, the prospects for measuring the properties of a Higgs boson like its mass and width, its CP eigenvalues and its couplings to fermions and gauge bosons are discussed
APDs as Single-Photon Detectors for Visible and Near-Infrared Wavelenghts down to Hz Rates
For the SPECTRAP experiment at GSI, Germany, detectors with Single-Photon
counting capability in the visible and near-infrared regime are required. For
the wavelength region up to 1100 nm we investigate the performance of 2x2 mm^2
avalanche photo diodes (APDs) of type S0223 manufactured by Radiation
Monitoring Devices. To minimize thermal noise, the APDs are cooled to
approximately -170 deg. C using liquid nitrogen. By operating the diodes close
to the breakdown voltage it is possible to achieve relative gains in excess of
2x10^4. Custom-made low noise preamplifiers are used to read out the devices.
The measurements presented in this paper have been obtained at a relative gain
of 2.2x10^4. At a discriminator threshold of 6 mV the resulting dark count rate
is in the region of 230/s. With these settings the studied APDs are able to
detect single photons at 628 nm wavelength with a photo detection efficiency of
(67+-7)%. Measurements at 1020 nm wavelength have been performed using the
attenuated output of a grating spectrograph with a light bulb as photon source.
With this setup the photo detection efficiency at 1020 nm has been determined
to be (13+-3)%, again at a threshold of 6 mV.Comment: 14 pages, 9 figures, submitted to Journal of Instrumentatio
Min-Max Theorems for Packing and Covering Odd -trails
We investigate the problem of packing and covering odd -trails in a
graph. A -trail is a -walk that is allowed to have repeated
vertices but no repeated edges. We call a trail odd if the number of edges in
the trail is odd. Let denote the maximum number of edge-disjoint odd
-trails, and denote the minimum size of an edge-set that
intersects every odd -trail.
We prove that . Our result is tight---there are
examples showing that ---and substantially improves upon
the bound of obtained in [Churchley et al 2016] for .
Our proof also yields a polynomial-time algorithm for finding a cover and a
collection of trails satisfying the above bounds.
Our proof is simple and has two main ingredients. We show that (loosely
speaking) the problem can be reduced to the problem of packing and covering odd
-trails losing a factor of 2 (either in the number of trails found, or
the size of the cover). Complementing this, we show that the
odd--trail packing and covering problems can be tackled by exploiting
a powerful min-max result of [Chudnovsky et al 2006] for packing
vertex-disjoint nonzero -paths in group-labeled graphs
APDs as Single-Photon Detectors for Visible and Near-Infrared Wavelenghts down to Hz Rates
For the SPECTRAP experiment at GSI, Germany, detectors with Single-Photon
counting capability in the visible and near-infrared regime are required. For
the wavelength region up to 1100 nm we investigate the performance of 2x2 mm^2
avalanche photo diodes (APDs) of type S0223 manufactured by Radiation
Monitoring Devices. To minimize thermal noise, the APDs are cooled to
approximately -170 deg. C using liquid nitrogen. By operating the diodes close
to the breakdown voltage it is possible to achieve relative gains in excess of
2x10^4. Custom-made low noise preamplifiers are used to read out the devices.
The measurements presented in this paper have been obtained at a relative gain
of 2.2x10^4. At a discriminator threshold of 6 mV the resulting dark count rate
is in the region of 230/s. With these settings the studied APDs are able to
detect single photons at 628 nm wavelength with a photo detection efficiency of
(67+-7)%. Measurements at 1020 nm wavelength have been performed using the
attenuated output of a grating spectrograph with a light bulb as photon source.
With this setup the photo detection efficiency at 1020 nm has been determined
to be (13+-3)%, again at a threshold of 6 mV.Comment: 14 pages, 9 figures, submitted to Journal of Instrumentatio
Winning Cores in Parity Games
We introduce the novel notion of winning cores in parity games and develop a
deterministic polynomial-time under-approximation algorithm for solving parity
games based on winning core approximation. Underlying this algorithm are a
number properties about winning cores which are interesting in their own right.
In particular, we show that the winning core and the winning region for a
player in a parity game are equivalently empty. Moreover, the winning core
contains all fatal attractors but is not necessarily a dominion itself.
Experimental results are very positive both with respect to quality of
approximation and running time. It outperforms existing state-of-the-art
algorithms significantly on most benchmarks
Creating Time for Research at Marshall University
Creating time for research is important, yet difficult. Creating large blocks of dedicated research time is nearly impossible. It is critical, therefore, that the institution encourages all levels to work in a coordinated effort to assist faculty in accessing those precious minutes and smaller blocks of time. At the departmental level the Management and Marketing Division conducts a Research and Teaching (R&T) Forum six to eight times per academic year. The forum allows the division’s 28 faculty members to brainstorm, find areas of similar interests, combine research efforts, and present a “test run” before submission to a journal or conference. This team approach saves a great deal of time for research in that two heads, or 28 as the case may be, are always better than one. Strengths and limitations of the presented material are discussed, other branches of potential research streams are noted, and personal “tips” are shared in the supportive atmosphere. Co-authored projects are encouraged among persons in the same discipline and across disciplines and subdisciplines
APDs as Single-Photon Detectors for Visible and Near-Infrared Wavelenghts down to Hz Rates
For the SPECTRAP experiment at GSI, Germany, detectors with Single-Photon
counting capability in the visible and near-infrared regime are required. For
the wavelength region up to 1100 nm we investigate the performance of 2x2 mm^2
avalanche photo diodes (APDs) of type S0223 manufactured by Radiation
Monitoring Devices. To minimize thermal noise, the APDs are cooled to
approximately -170 deg. C using liquid nitrogen. By operating the diodes close
to the breakdown voltage it is possible to achieve relative gains in excess of
2x10^4. Custom-made low noise preamplifiers are used to read out the devices.
The measurements presented in this paper have been obtained at a relative gain
of 2.2x10^4. At a discriminator threshold of 6 mV the resulting dark count rate
is in the region of 230/s. With these settings the studied APDs are able to
detect single photons at 628 nm wavelength with a photo detection efficiency of
(67+-7)%. Measurements at 1020 nm wavelength have been performed using the
attenuated output of a grating spectrograph with a light bulb as photon source.
With this setup the photo detection efficiency at 1020 nm has been determined
to be (13+-3)%, again at a threshold of 6 mV.Comment: 14 pages, 9 figures, submitted to Journal of Instrumentatio
Hydrodynamic lift of vesicles under shear flow in microgravity
The dynamics of a vesicle suspension in a shear flow between parallel plates
has been investigated under microgravity conditions, where vesicles are only
submitted to hydrodynamic effects such as lift forces due to the presence of
walls and drag forces. The temporal evolution of the spatial distribution of
the vesicles has been recorded thanks to digital holographic microscopy, during
parabolic flights and under normal gravity conditions. The collected data
demonstrates that vesicles are pushed away from the walls with a lift velocity
proportional to where is the shear rate,
the vesicle radius and its distance from the wall. This scaling as well
as the dependence of the lift velocity upon vesicle aspect ratio are consistent
with theoretical predictions by Olla [J. Phys. II France {\bf 7}, 1533--1540
(1997)].Comment: 6 pages, 8 figure
Assessing Regulatory Impact Analyses: The Failure of Agencies to Comply With Executive Order 12,866
None.Environment, Health and Safety, Regulatory Reform
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