4,260 research outputs found
Summary of the Superconducting RF Linac for Muon Collider and Neutrino Factory
Project-X is a proposed project to be built at Fermi National Accelerator
Laboratory with several potential missions. A primary part of the Project-X
accelerator chain is a Superconducting linac, and In October 2009 a workshop
was held to concentrate on the linac parameters. The charge of the workshop was
to "..focus only on the SRF linac approaches and how it can be used...". The
focus of Working Group 2 of this workshop was to evaluate how the different
linac options being considered impact the potential realization of Muon
Collider (MC) and Neutrino Factory (NF) applications. In particular the working
group charge was, "to investigate the use of a multi-megawatt proton linac to
target, phase rotate and collect muons to support a muon collider and neutrino
factory". To focus the working group discussion, three primary questions were
identified early on, to serve as a reference: 1) What are the proton source
requirements for muon colliders and neutrino factories? 2) What are the issues
with respect to realizing the required muon collider and neutrino factory
proton sources? a. General considerations b. Considerations specific to the two
linac configurations identified by Project-X. 3) What things need to be done
before we can be reasonably confident that ICD1/ICD2 can be upgraded to provide
the neutrino factory / muon collider needs? A number of presentations were
given, and are available at the workshop web-site. This paper does not
summarize the individual presentations, but rather addresses overall findings
as related to the three guiding questions listed above.Comment: 6 pp. Workshop on Applications of High Intensity Proton Accelerators
19-21 Oct 2009: Batavia, Illinoi
Exploring Neutrino Oscillations with Superbeams
We consider the medium- and long-baseline oscillation physics capabilities of
intense muon-neutrino and muon-antineutrino beams produced using future
upgraded megawatt-scale high-energy proton beams. In particular we consider the
potential of these conventional neutrino ``superbeams'' for observing
\nu_\mu\to\nu_e oscillations, determining the hierarchy of neutrino mass
eigenstates, and measuring CP-violation in the lepton sector. The physics
capabilities of superbeams are explored as a function of the beam energy,
baseline, and the detector parameters. The trade-offs between very large
detectors with poor background rejection and smaller detectors with excellent
background rejection are illustrated. We find that it may be possible to
observe \nu_\mu\to\nu_e oscillations with a superbeam provided that the
amplitude parameter \sin^2 2\theta_{13} is larger than a few \times 10^{-3}. If
\sin^2 2\theta_{13} is of order 10^{-2} or larger, then the neutrino mass
hierarchy can be determined in long-baseline experiments, and if in addition
the large mixing angle MSW solution describes the solar neutrino deficit then
there is a small region of parameter space within which maximal CP-violation in
the lepton sector would be observable in a low-energy medium-baseline
experiment. We explicitly consider massive water Cherenkov and liquid argon
detectors at superbeams with neutrino energies ranging from 1 GeV to 15 GeV,
and baselines from 295 km to 9300 km. Finally, we compare the oscillation
physics prospects at superbeams with the corresponding prospects at neutrino
factories. The sensitivity at a neutrino factory to CP violation and the
neutrino mass hierarchy extends to values of the amplitude parameter \sin^2
2\theta_{13} that are one to two orders of magnitude lower than at a superbeam.Comment: Revtex (singlespaced), 41 pages, uses epsf.sty, 12 postscript
figures. Minor corrections and notation changes, expanded discussions, x-axis
numbers added to Fig.9(a),(c). To be published in Phys. Rev.
Neutrino Factories: Physics Potential
The physics potential of low-performance and high-performance neutrino
factories is briefly reviewed..Comment: Talk presented at NUFACT02, London, 1-6 July, 2002. 8 pages, 5
figure
Effects of listening to music in a precompetition routine on mood and performance
Members of a Division I university women\u27s rowing team ( n = 14) each performed three rowing tasks under three music conditions that asked the participants to use headphones to listen to self-selected music either, (1) not at all, (2) during their precompetition routine, or (3) during the rowing task. Positive and negative affect was assessed immediately prior to and after each task. Results indicated that mood did not differ across music conditions and was not affected by current music use or skill level (p\u27s \u3e .05). No significant differences in time to complete the tasks were found across the three music conditions ( p\u27s \u3e .05). However, a statistically significant negative correlation was found between pre-task positive affect and time under the preparation music condition (r = -.64, p \u3c .05), such that as positive affect before the rowing task increased, time to complete the task decreased
Searches for new physics through single top
Nowadays particle physics research involves building the largest machines ever built. Detectors the size of a palace buried deep underground, aligned to tiny fractions of a millimeter, observe billions of collisions a second. Large collaborations of thousands of people analyze the unfathomably large amounts of data the detectors produce. A million computers sort through the data running software that is so complex that no-one can even come close to understanding every detail. These experiments search for deviations from the Standard Model that may point to so-called new physics. The new physics may lead to answers to some of the big open questions of science, such as: Why does our universe contain primarily matter, and hardly any anti-matter? This question of baryogenesis is the main motivation for the analyses described in this thesis. Chapter 1 gives a short theoretical introduction to single top processes, and describes the theory behind the analyses. Experiment follows the theory, with a description of the ATLAS experiment and the LHC in chapter 2. Once your appetite has been whetted, chapter 3 will provide you with many details on the performance of the detector, the reconstruction of physics objects in the detector and the simulation of collisions and detector response. Now comes the analysis: a search for excited b quarks in the single top Wt-channel is described in chapter 4. Then we switch channels: an analysis in single top t-channel is spread over two chapters: chapter 5 describes a cut and count measurement of the t-channel cross section and finally chapter 6 describes a search for CP-violation in the t-channel
Study of high-speed angular-contact ball bearings under dynamic load
Research program studies behavior of specific high-speed, angular-contact ball bearings. Program is aimed at detailed investigation of ball-separator behavior and lubrication surface-finish effects in a specific gyro wheel
Detecting multivariate interactions in spatial point patterns with Gibbs models and variable selection
We propose a method for detecting significant interactions in very large
multivariate spatial point patterns. This methodology develops high dimensional
data understanding in the point process setting. The method is based on
modelling the patterns using a flexible Gibbs point process model to directly
characterise point-to-point interactions at different spatial scales. By using
the Gibbs framework significant interactions can also be captured at small
scales. Subsequently, the Gibbs point process is fitted using a
pseudo-likelihood approximation, and we select significant interactions
automatically using the group lasso penalty with this likelihood approximation.
Thus we estimate the multivariate interactions stably even in this setting. We
demonstrate the feasibility of the method with a simulation study and show its
power by applying it to a large and complex rainforest plant population data
set of 83 species
Search for muonic decays of the antiproton at the Fermilab Antiproton Accumulator
A search for antiproton decay has been made at the Fermilab Antiproton
Accumulator. Limits are placed on six antiproton decay modes which contain a
final-state muon. At the 90% C.L. we find that
tau/B(mu gamma) > 5.0 x 10^4 yr,
tau/B(mu pi0) > 4.8 x 10^4 yr,
tau/B(mu eta) > 7.9 x 10^3 yr,
tau/B(mu gamma gamma) > 2.3 x 10^4 yr,
tau/B(mu K0S > 4.3 x 10^3 yr, and
tau/B(mu K0L) > 6.5 x 10^3 yr.Comment: 8 pages + 3 Postscript figure
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