5,609 research outputs found
The gas phase cyclization of deprotonated N-aryl-2-cyano-2-diazoacetamides
The document attached has been archived with permission from the publisher.1-Aryl-4-cyano-5-hydroxy-1,2,3-triazoles can be obtained in solution by base-catalysed cyclization of N-aryl-2-cyano-2-diazoacetamides. A similar reaction was shown to take place under conditions of negative ion chemical ionization in the ion source of a mass spectrometer. High resolution mass spectrometry, tandem mass spectrometry, charge reversal spectra, synthesis of the ions with known structures and quantum chemical calculations were used to prove the latter statement. The fact of the observed cyclization demonstrates once again the ability of mass spectrometry to study the gas phase chemical reactions that take place in solution.Vladislav V. Lobodin, Yuriy Yu. Morzherin, Tom Blumenthal, Daniel Bilusich, Vladimir V. Ovcharenko, John H. Bowie, and Albert T. Lebede
Astrophysical jets: observations, numerical simulations, and laboratory experiments
This paper provides summaries of ten talks on astrophysical jets given at the HEDP/HEDLA-08 International Conference in St. Louis. The talks are topically divided into the areas of observation, numerical modeling, and laboratory experiment. One essential feature of jets, namely, their filamentary (i.e., collimated) nature, can be reproduced in both numerical models and laboratory experiments. Another essential feature of jets, their scalability, is evident from the large number of astrophysical situations where jets occur. This scalability is the reason why laboratory experiments simulating jets are possible and why the same theoretical models can be used for both observed astrophysical jets and laboratory simulations
Invisible Higgs and Scalar Dark Matter
In this proceeding, we show that when we combined WMAP and the most recent
results of XENON100, the invisible width of the Higgs to scalar dark matter is
negligible(<10%), except in a small region with very light dark matter (< 10
GeV) not yet excluded by XENON100 or around 60 GeV where the ratio can reach
50% to 60%. The new results released by the Higgs searches of ATLAS and CMS set
very strong limits on the elastic scattering cross section.Comment: 4 pages, 2 figures, proceeding TAUP2011 References adde
Meteoprotective properties of melaxen in old and middle aged patients with ischemic heart disease in combination with arterial hypertension
We studied 102 patients (mean age 60.1±3.3 years) with arterial hypertension (AH) II-III stage, grade 2-3 and ischemic heart disease (exertional angina functional class (FC) I-II, postinfarction cardiosclerosis). The control group of patients received traditional therapy (TT): beta -blockers, calcium channel blockers, ACE inhibitors, antiplatelet agents, diuretics and nitrate
Searching singlet extensions of the supersymmetric standard model in orbifold compactification of heterotic string
We search for supersymmetric standard model realizations with extra singlets
and extra using the heterotic string compactification on the orbifold with two Wilson lines. We analyze the vacuum restabilization
mechanism for three representative Pati-Salam string models obtained in the
literature and present detailed results for the effective superpotential
compatible with the string selection rules. An automated selection of
semi-realistic vacua along flat directions in the non-Abelian singlet modes
field space is performed by requiring the presence of massless pairs of
electroweak Higgs bosons having trilinear superpotential couplings with
massless singlet modes and the decoupling of color triplet exotic modes needed
to suppress and number violating processes.Comment: revtex4 format, 21 pages, 7 tables, shortened version added
reference
The risks of developing adverse outcomes according to geriatric status in patients with coronary heart disease with plannedaorto-coronary artery bypass grafting
The article assesses the risks of developing adverse outcomes in patients with coronary heart disease who underwent planned aorto-coronary artery bypass grafting according to geriatric status using such scales as the cardiovascular health study frailt
Discrete R-symmetries and Anomaly Universality in Heterotic Orbifolds
We study discrete R-symmetries, which appear in 4D low energy effective field
theory derived from hetetoric orbifold models. We derive the R-symmetries
directly from geometrical symmetries of orbifolds. In particular, we obtain the
corresponding R-charges by requiring that the couplings be invariant under
these symmetries. This allows for a more general treatment than the explicit
computations of correlation functions made previously by the authors, including
models with discrete Wilson lines, and orbifold symmetries beyond
plane-by-plane rotational invariance. Surprisingly, for the cases covered by
earlier explicit computations, the R-charges differ from the previous result.
We study the anomalies associated with these R-symmetries, and comment on the
results.Comment: 21 pages, 2 figures. Minor changes, typos corrected. Matches JHEP
published versio
Damping Rate of a Hard Photon in a Relativistic Plasma
The damping rate of a hard photon in a hot relativistic QED and QCD plasma is
calculated using the resummation technique by Braaten and Pisarski.Comment: 4 pages, REVTeX, 2 figures (not included), UGI-MT-94-0
Central factorials under the Kontorovich-Lebedev transform of polynomials
We show that slight modifications of the Kontorovich-Lebedev transform lead
to an automorphism of the vector space of polynomials. This circumstance along
with the Mellin transformation property of the modified Bessel functions
perform the passage of monomials to central factorial polynomials. A special
attention is driven to the polynomial sequences whose KL-transform is the
canonical sequence, which will be fully characterized. Finally, new identities
between the central factorials and the Euler polynomials are found.Comment: also available at http://cmup.fc.up.pt/cmup/ since the 2nd August
201
The NuTeV Anomaly, Neutrino Mixing, and a Heavy Higgs Boson
Recent results from the NuTeV experiment at Fermilab and the deviation of the
Z invisible width, measured at LEP/SLC, from its Standard Model (SM) prediction
suggest the suppression of neutrino-Z couplings. Such suppressions occur
naturally in models which mix the neutrinos with heavy gauge singlet states. We
postulate a universal suppression of the Z-nu-nu couplings by a factor of
(1-epsilon) and perform a fit to the Z-pole and NuTeV observables with epsilon
and the oblique correction parameters S and T. Compared to a fit with S and T
only, inclusion of epsilon leads to a dramatic improvement in the quality of
the fit. The values of S and T preferred by the fit can be obtained within the
SM by a simple increase in the Higgs boson mass. However, if the W mass is also
included in the fit, a non-zero U parameter becomes necessary which cannot be
supplied within the SM. The preferred value of epsilon suggests that the seesaw
mechanism may not be the reason why neutrinos are so light.Comment: 19 pages, REVTeX4, 8 postscript figures. Updated references. Typos
correcte
- …