8,009 research outputs found
The Scientific Need for a Scalar/Higgs Factory
The scalar sector of the electroweak theory can be probed by a mu^+mu^-
collider S channel resonance machine. We give arguments for when such a machine
may be needed and when this information could be obtained by the LHC detector.
A very interesting case is the possibility that several scalar particles are in
the same mass range for the supersymmetric Higgs bosons h, H, and A, which
would definitely require such a machine. The Higgs factory could follow the
construction of a neutrino factory.Comment: 6 pages. Presented at the 5th Int. Conf. sponsored by UCLA on the
Physics Potential and Development of mu^+mu^- Colliders (San Francisco, Dec.
15-17, 1999) and to be published in the Proceedings by AI
Unlocking Undergraduate Problem Solving
It is difficult to find good problems for undergraduates. In this article, we explore an interesting problem that can be used in virtually any mathematics course. We then offer natural generalizations, state and prove some related results, and ultimately end with several open problems suitable for undergraduate research. Finally, we attempt to shed some light on what makes a problem interesting
Testing neutrino spectra formation in collapsing stars with the diffuse supernova neutrino flux
I address the question of what can be learned from the observation of the
diffuse supernova neutrino flux in the precision phase, at next generation
detectors of Megaton scale. An analytical study of the spectrum of the diffuse
flux shows that, above realistic detection thresholds of 10 MeV or higher, the
spectrum essentially reflects the exponential-times-polynomial structure of the
original neutrino spectrum at the emission point. There is only a weak (tens of
per cent) dependence on the power \beta describing the growth of the supernova
rate with the redshift. Different original neutrino spectra correspond to large
differences in the observed spectrum of events at a water Cerenkov detector:
for typical supernova rates, the ratio of the numbers of events in the first
and second energy bins (of 5 MeV width) varies in the interval 1.5 - 4.3 for
pure water (energy threshold 18 MeV) and in the range 1 - 2.5 for water with
Gadolinium (10 MeV threshold). In the first case discrimination would be
difficult due to the large errors associated with background. With Gadolinium,
instead, the reduction of the total error down to 10-20 % level would allow
spectral sensitivity, with a dramatic improvement of precision with respect to
the SN1987A data. Even in this latter case, for typical neutrino luminosity the
dependence on \beta is below sensitivity, so that it can be safely neglected in
data analysis.Comment: LaTeX, 10 pages, 5 figures; details added to fig. 5 and related text,
minor modifications to the text, references added. Version in press in
Phys.Rev.D
A Neutrino-Factory Muon Storage Ring to Provide Beams for Multiple Detectors Around the World
We briefly discuss the physics motivation for a neutrino factory with varying
baseline distances of about 1000 to 9000 km. We describe the amount of non
planarity of the storage ring required to service three or four detectors at
once. A novel bowtie storage ring is described that could in part provide these
beams; a preliminary lattice design is given. We give the space angles between
the various detector locations and possible sites for neutrino factories.
Finally we describe detectors at the Gran Sasso Laboratory and at a new
laboratory near Carlsbad, NM to observe the neutrino interactions with wrong
sign leptons.Comment: 8 pages. Presented at the 5th Int. Conf. sponsored by UCLA on the
Physics Potential and Develoment of mu^+mu^- Colliders (San Francisco,
December 15-17, 1999) and to be published in the Proceedings by AI
CF6 High Pressure Compressor and Turbine Clearance Evaluations
In the CF6 Jet Engine Diagnostics Program the causes of performance degradation were determined for each component of revenue service engines. It was found that a significant contribution to performance degradation was caused by increased airfoil tip radial clearances in the high pressure compressor and turbine areas. Since the influence of these clearances on engine performance and fuel consumption is significant, it is important to accurately establish these relatonships. It is equally important to understand the causes of clearance deterioration so that they can be reduced or eliminated. The results of factory engine tests run to enhance the understanding of the high pressure compressor and turbine clearance effects on performance are described. The causes of clearance deterioration are indicated and potential improvements in clearance control are discussed
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