2,736 research outputs found
High-Mass Supersymmetry with High Energy Hadron Colliders
While it is natural for supersymmetric particles to be well within the mass
range of the large hadron collider, it is possible that the sparticle masses
could be very heavy. Signatures are examined at a very high energy hadron
collider and an very high luminosity option for the Large Hadron Collider in
such scenarios
Lamp enables measurement of oxygen concentration in presence of water vapor
Open-electrode ultraviolet source lamp radiates sufficient energy at 1800 angstroms and 1470 angstroms for use in a double-beam, duel-wavelength oxygen sensor. The lamp is filled with xenon at a pressure of 100 mm of Hg
Measurements in Gauge Mediated SUSY Breaking Models at LHC
Characteristic examples are presented of scenarios of particle production and
decay in supersymmetry models in which the supersymmetry breaking is
transmitted to the observable world via gauge interactions. The cases are
chosen to illustrate the main classes of LHC phenomenology that can arise in
these models. A new technique is illustrated that allows the full
reconstruction of supersymmetry events despite the presence of two unobserved
particles. This technique enables superparticle masses to be measured directly
rather than being inferred from kinematic distributions. It is demonstrated
that the LHC is capable of making sufficient measurements so as to severely
over-constrain the model and determine the parameters with great precisionComment: 45 pages, 35 Figure
Measurements in SUGRA Models with Large tan beta at LHC
We present an example of a scenario of particle production and decay in
supersymmetry models in which the supersymmetry breaking is transmitted to the
observable world via gravitational interactions. The case is chosen so that
there is a large production of tau leptons in the final state. It is
characteristic of large tan beta in that decays into muons and electrons may be
suppressed. It is shown that hadronic tau decays can be used to reconstruct
final states.Comment: 15 pages, 12 figure
Neutralino-neutralino annihilation to gammaZ in MSSM
The 1-loop computation of the processes \tchi_i \tchi_j \to \gamma Z has
been performed at an arbitrary c.m. energy for any pair of MSSM neutralinos. As
an application suitable for Dark Matter (DM) searches, the
neutralino-neutralino annihilation is studied at the limiting case of vanishing
relative velocity, describing the present DM distribution in the galactic halo;
and at a relative velocity of about 0.5, determining the neutralino relic
density contributions. The most useful situation is obviously for , but
the case of non-identical neutralinos may also be useful in some corners of the
parameter space. Our results are contained in the FORTRAN code PLATONdmgZ,
applying to any set of real MSSM parameters. Numerical results are also
presented for a sample of 6 MSSM models, describing the various possible
neutralino properties. A comparison with other existing works is also made.Comment: 14 pages, 7 figures, Version to appear in Physical Review
Precision SUSY Measurements at LHC
If supersymmetry exists at the electroweak scale, then it should be
discovered at the LHC. Determining masses, of supersymmetric particles however,
is more difficult. In this paper, methods are discussed to determine
combinations of masses and of branching ratios precisely from experimentally
observable distributions. In many cases such measurements alone can greatly
constrain the particular supersymmetric model and determine its parameters with
an accuracy of a few percent. Most of the results shown correspond to one year
of running at LHC at ``low luminosity'.Comment: 52 pages, Latex with 42 postscript figures. Postscript version also
at http://www-physics.lbl.gov/www/theorygroup/papers/39412.p
3,6-dimethoxyxanthone from 2,2’,4,4’- tetrahydroxy-benzophenone via Microwave-Assisted Annulation
Xanthones are tricyclic aromatic compounds that have multiple pharmacological uses due to their anti-tumor, antioxidant, anti-inflammatory, anti-bacterial, and potentially chemopreventive properties. The target of this research was to optimize a two-step synthesis of 3,6-dimethoxyxanthone (3) from 2,2’,4,4’-tetrahydroxy-benzophenone (1) via microwave-assisted (200 °C, 30-40 min., 150 W) sodium acetate-catalyzed annulation. The product, 3,6-dihydroxyxanthone (2), was then methylated to (3) using dimethyl sulfate (DMS) and sodium carbonate in acetone at reflux. The product yields were 93% (\u3e99% purity) for (2) and 94% (\u3e99% purity) for (3). Characterization was accomplished using 1H NMR, FTIR, melting point, TLC, HPLC, and GCMS. The product (3) was made available for additional screening and research, such as synthesizing dyes like fluorescein and its derivatives
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