5,618 research outputs found
Bosonic Quartic Couplings at LEP2
We list the set of C and P conserving anomalous quartic vector bosons
self-couplings which can be tested at LEP2 through triple vector boson
production. We show how this set can be embedded in manifestly SU(2)xU(1) gauge
invariant operators exhibiting an SU(2)_c global symmetry. We derive bounds on
these various couplings and show the most relevant distributions that can
enhance their contribution. We also find that an e+e- collider running at 500
GeV can improve the LEP2 limits by as much as three orders of magnitude.Comment: 21 pages, 7 figure
Non-volatile bistability effect based on electrically controlled phase transition in scaled magnetic semiconductor nanostructures
We explore the bistability effect in a dimensionally scaled semiconductor
nanostruncture consisting of a diluted magnetic semiconductor quantum dot (QD)
and a reservoir of itinerant holes separated by a barrier. The bistability
stems from the magnetic phase transition in the QD mediated by the changes in
the hole population. Our calculation shows that when properly designed, the
thermodynamic equilibrium of the scaled structure can be achieved at two
different configurations; i.e., the one with the QD in a ferromagnetic state
with a sufficient number of holes and the other with the depopulated QD in a
paramagnetic state. Subsequently, the parameter window suitable for this
bistability formation is discussed along with the the conditions for the
maximum robustness/non-volatility. To examine the issue of scaling, an
estimation of the bistabiity lifetime is made by considering the thermal
fluctuation in the QD hole population via the spontaneous transitions. A
numerical evaluation is carried out for a typical carrier-mediated magnetic
semiconductor (e.g., GaMnAs) as well as for a hypothetical case of high Curie
temperature for potential room temperature operation.Comment: 9 pages, 7 figure
Environmental and economic damage from the development of oil and gas fields in the Arctic shelf of the Russian Federation
The aim of the paper is the development of a technique of assessment of possible ecological and economic damage to air resources during the development of offshore fields for ensuring sustainable development of the Arctic region of Russia.
The use of a modified temporary method for determining the prevented environmental damage is proposed to point out the possible environmental and economic damage by Monte Carlo mathematical modelling.
After calculations authors made a conclusion about the most rational method for calculating damage from the offshore Arctic oil and gas projects in the water of the Ob-Taz Bay in the Kara Sea.
The practical significance of this work is that the proposed methodology can be applied to all oil and gas fields on the Arctic shelf of Russia for measuring potential damages from air pollution as well as soil and water pollution.peer-reviewe
Energy spectrum of cascades generated by muons in Baksan underground scintillation telescope
Spectrum of cascades generated by cosmic ray muons underground is presented. The mean zenith angle of the muon arrival is theta=35 deg the depth approx. 1000 hg/sq cm. In cascades energy range 700 GeV the measured spectrum is in agreement with the sea-level integral muon spectrum index gamma=3.0. Some decrease of this exponent has been found in the range 4000 Gev
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