4,524 research outputs found
Mixings, Lifetimes, Spectroscopy and Production of Heavy Flavor at the Tevatron
The Fermilab Tevatron offers unique opportunities to perform measurements of
the heavier B hadrons that are not accessible at the Upsilon(4S) resonance. In
this summary, we describe some recent heavy flavor results from the DO and CDF
collaborations and discuss prospects for future measurements.Comment: To appear in Proceedings of the XXI International Symposium on lepton
and Photon Interactions at High Energies, Fermilab, August 200
Searching for Doubly-Charged Higgs Bosons at Future Colliders
Doubly-charged Higgs bosons () appear in several
extensions to the Standard Model and can be relatively light. We review the
theoretical motivation for these states and present a study of the discovery
reach in future runs of the Fermilab Tevatron for pair-produced doubly-charged
Higgs bosons decaying to like-sign lepton pairs. We also comment on the
discovery potential at other future colliders.Comment: 6 pages, full postscript file also available via anonymous ftp at
ftp://ucdhep.ucdavis.edu/gunion/hmm_sm96.ps To appear in ``Proceedings of the
1996 DPF/DPB Summer Study on New Directions for High Energy Physics'
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The CDF Central Outer Tracker
We describe the CDF Central Outer Tracker (COT), an open-cell drift chamber currently being constructed for the CDF detector to run at the upgraded Fermilab Tevatron collider. This detector will provide central tracking with excellent momentum resolution in the high- density environment of a hadron collider. It will be able to resolve 132 ns beam crossings and provide tracking trigger information to the Level 1 trigger. The design is based upon the existing and successful CDF Central Tracking Chamber. The preliminary mechanical and electrical designs are presented. 5 refs., 5 figs., 1 tab
Measurement of Total (p,Pi) Cross Sections Through Residual Activity
This work was supported by the National Science Foundation Grants NSF PHY 78-22774 A03, NSF PHY 81-14339, and by Indiana Universit
Nonaxisymmetric Magnetorotational Instability in Proto-Neutron Stars
We investigate the stability of differentially rotating proto-neutron stars
(PNSs) with a toroidal magnetic field. Stability criteria for nonaxisymmetric
MHD instabilities are derived using a local linear analysis. PNSs are expected
to have much stronger radial shear in the rotation velocity compared to normal
stars. We find that nonaxisymmetric magnetorotational instability (NMRI) with a
large azimuthal wavenumber is dominant over the kink mode () in
differentially rotating PNSs. The growth rate of the NMRI is of the order of
the angular velocity which is faster than that of the kink-type
instability by several orders of magnitude. The stability criteria are
analogous to those of the axisymmetric magnetorotational instability with a
poloidal field, although the effects of leptonic gradients are considered in
our analysis. The NMRI can grow even in convectively stable layers if the
wavevectors of unstable modes are parallel to the restoring force by the
Brunt-V\"ais\"al\"a oscillation. The nonlinear evolution of NMRI could amplify
the magnetic fields and drive MHD turbulence in PNSs, which may lead to
enhancement of the neutrino luminosity.Comment: 24pages, 7figures, Accepted for publication in the Astrophysical
Journal (December 12, 2005
Predicting the safety and efficacy of butter therapy to raise tumour pHe: an integrative modelling study
Background: Clinical positron emission tomography imaging has demonstrated the vast majority of human cancers exhibit significantly increased glucose metabolism when compared with adjacent normal tissue, resulting in an acidic tumour microenvironment. Recent studies demonstrated reducing this acidity through systemic buffers significantly inhibits development and growth of metastases in mouse xenografts.\ud
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Methods: We apply and extend a previously developed mathematical model of blood and tumour buffering to examine the impact of oral administration of bicarbonate buffer in mice, and the potential impact in humans. We recapitulate the experimentally observed tumour pHe effect of buffer therapy, testing a model prediction in vivo in mice. We parameterise the model to humans to determine the translational safety and efficacy, and predict patient subgroups who could have enhanced treatment response, and the most promising combination or alternative buffer therapies.\ud
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Results: The model predicts a previously unseen potentially dangerous elevation in blood pHe resulting from bicarbonate therapy in mice, which is confirmed by our in vivo experiments. Simulations predict limited efficacy of bicarbonate, especially in humans with more aggressive cancers. We predict buffer therapy would be most effectual: in elderly patients or individuals with renal impairments; in combination with proton production inhibitors (such as dichloroacetate), renal glomular filtration rate inhibitors (such as non-steroidal anti-inflammatory drugs and angiotensin-converting enzyme inhibitors), or with an alternative buffer reagent possessing an optimal pK of 7.1–7.2.\ud
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Conclusion: Our mathematical model confirms bicarbonate acts as an effective agent to raise tumour pHe, but potentially induces metabolic alkalosis at the high doses necessary for tumour pHe normalisation. We predict use in elderly patients or in combination with proton production inhibitors or buffers with a pK of 7.1–7.2 is most promising
Pionium Production in the Cooler
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Near Threshold Pion Production via 2-H(p,pi-0)3-He
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Long-term fuel retention and release in JET ITER-Like Wall at ITER-relevant baking temperatures
The fuel outgassing efficiency from plasma-facing components exposed in JET-ILW has been studied at ITER-relevant baking temperatures. Samples retrieved from the W divertor and Be main chamber were annealed at 350 and 240 degrees C, respectively. Annealing was performed with thermal desoprtion spectrometry (TDS) for 0, 5 and 15 h to study the deuterium removal effectiveness at the nominal baking temperatures. The remained fraction was determined by emptying the samples fully of deuterium by heating W and Be samples up to 1000 and 775 degrees C, respectively. Results showed the deposits in the divertor having an increasing effect to the remaining retention at temperatures above baking. Highest remaining fractions 54 and 87% were observed with deposit thicknesses of 10 and 40 mu m, respectively. Substantially high fractions were obtained in the main chamber samples from the deposit-free erosion zone of the limiter midplane, in which the dominant fuel retention mechanism is via implantation: 15 h annealing resulted in retained deuterium higher than 90%. TDS results from the divertor were simulated with TMAP7 calculations. The spectra were modelled with three deuterium activation energies resulting in good agreement with the experiments.Peer reviewe
Pionium Production in the Cooler
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
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