29,354 research outputs found
Electroweakino constraints from LHC data
We investigate the sensitivity of existing LHC searches to the charginos and
neutralinos of the MSSM when all the other superpartners are decoupled. In this
limit, the underlying parameter space reduces to a simple four-dimensional set
. We examine the constraints placed on this
parameter space by a broad range of LHC searches taking into account the full
set of relevant production and decay channels. We find that the exclusions
implied by these searches exceed existing limits from LEP only for smaller
values of the Bino mass GeV. Our results have implications
for MSSM dark matter and electroweak baryogenesis.Comment: 30 pages, 15 figure
The Effect of Recent and Futuristic Changes in Cotton Production Technology on Direct and Fixed Costs Per Acre, Mississippi, 2004
The introduction of genetically modified seed technology dramatically changed cotton production practices. Production systems based on reduced tillage and BtRR varieties improved net returns by $47.35 per acre (53%) when compared to systems based on conventional tillage and non-transgenic varieties. The impact of other technology induced changes are reported.Crop Production/Industries,
OUTPUT CHANGE IN U.S. AGRICULTURE: AN INPUT-OUTPUT ANALYSIS
This paper analyzes output changes in the U.S. agricultural economy from 1972 to 1977 using a 477-sector input-output framework. The empirical model is based on benchmark input-output data from the U.S. Bureau of Economic analysis for 1972 and 1977. Output changes were decomposed into components attributable to technical change, domestic final demand change, export demand change and import substitution. A major advantage of the decomposition is its ability to identify the output change in a given sector due to general equilibrium effects in all sectors.Import substitution, Input-output, Output change, Technical change, Production Economics,
Coherent versus incoherent excitation dynamics in dissipative many-body Rydberg systems
We study the impact of dephasing on the excitation dynamics of a cloud of
ultracold two-level Rydberg atoms for both resonant and off-resonant laser
excitation, using the wave function Monte Carlo (MCWF) technique. We find that
while for resonant laser driving, dephasing mainly leads to an increase of the
Rydberg population and a decrease of the Mandel Q parameter, at off-resonant
driving strong dephasing toggles between direct excitation of pairs of atoms
and subsequent excitation of single atoms, respectively. These two excitation
mechanisms can be directly quantified via the pair correlation function, which
shows strong suppression of the two-photon resonance peak for strong dephasing.
Consequently, qualitatively different dynamics arise in the excitation
statistics for weak and strong dephasing in off-resonant excitation. Our
findings show that time-resolved excitation number measurements can serve as a
powerful tool to identify the dominating process in the system's excitation
dynamics.Comment: 10 pages, 10 figure
Collection and analysis of radar rainfall and satellite data for the Darwin TRMM experiment
The following subject areas are covered: video cloud camera (purpose, design, operation, data); special observing periods (SOP-2, SOP 2.5 - an extension of SOP-2); Garand algorithm; and warm rain
Two-channel Kondo physics in tunnel-coupled double quantum dots
We investigate theoretically the possibility of observing two-channel Kondo
(2CK) physics in tunnel-coupled double quantum dots (TCDQDs), at both zero and
finite magnetic fields; taking the two-impurity Anderson model (2AIM) as the
basic TCDQD model, together with effective low-energy models arising from it by
Schrieffer-Wolff transformations to second and third order in the tunnel
couplings. The models are studied primarily using Wilson's numerical
renormalization group. At zero-field our basic conclusion is that while 2CK
physics arises in principle provided the system is sufficiently
strongly-correlated, the temperature window over which it could be observed is
much lower than is experimentally feasible. This finding disagrees with recent
work on the problem, and we explain why. At finite field, we show that the
quantum phase transition known to arise at zero-field in the two-impurity Kondo
model (2IKM), with an essentially 2CK quantum critical point, persists at
finite fields. This raises the prospect of access to 2CK physics by tuning a
magnetic field, although preliminary investigation suggests this to be even
less feasible than at zero field.Comment: 10 pages, 8 figures. Version as published in PR
Particle-level pileup subtraction for jets and jet shapes
We present an extension to the jet area-based pileup subtraction for both jet
kinematics and jet shapes. A particle-level approach is explored whereby the
jet constituents are corrected or removed using an extension of the methods
currently being employed by the LHC experiments. Several jet shapes and nominal
jet radii are used to assess the performance in simulated events with pileup
levels equivalent to approximately 30 and 100 interactions per bunch crossing,
which are characteristic of both the LHC Run I and Run II conditions. An
improved performance in removing the pileup contributions is found when using
the new subtraction method. The performance of the new procedure is also
compared to other existing methods
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