814 research outputs found
Allowed slepton intergenerational mixing in light of light element abundances
We studied allowed region on the intergenerational mixing parameters of
sleptons from a viewpoint of big-bang nucleosynthesis in a slepton-neutralino
coannihilation scenario. In this scenario, Li and Li problems can be
solved by considering exotic reactions caused by bound-state effects with a
long-lived slepton. Light element abundances are calculated as functions of the
relic density and lifetime of the slepton which considerably depend on the
intergenerational mixing parameters. Compared with observational light element
abundances, we obtain allowed regions on the intergenerational mixing. Ratio of
selectron component to stau component, , is allowed in with solving both the Li and Li
problems. Similarly, the ratio for smuon, , is allowed in for mass difference between
slepton and neutralino, which is smaller than muon mass, and for the mass difference in
range between muon mass and 125 MeV. We also discuss collider signatures of the
slepton decays. We find characteristic double peaks in momentum distribution of
event number of the slepton decays with allowed mixing parameters. Discoveries
of the double peaks at future collider experiments should confirm our scenario.Comment: 10 pages, 6 figure
First-principles method justifying the Dieke diagram and beyond
We present a method to determine the model Hamiltonians to treat rare-earth
multiplets in solids from the results of the quasiparticle self-consistent
\textit{GW} (QSGW) method. We apply the method to trivalent Eu compounds
EuCl, EuN, and Eu-doped GaN after examining free rare-earth ions. We solve
the model Hamiltonian by the exact diagonalization. Our results justify
applying the Dieke diagram to ions in solid, while its limitation is clarified.
In particular, we show that the crystal fields cause sizable breaking of the
Russell-Saunders coupling.Comment: 7 pages, 3 figures, 2 table
Development of ballast water treatment technology by mechanochemical cavitations
In order to solve environmental problems caused by ballast water, which is a serious problem worldwide, ballast water purification using cavitation was investigated. Previously, only the collapse pressure of cavitation was used for the treatment of planktons. In this study, however, processing by cavitation containing a chemical and the mechanical processing of cavitation were applied. A Venturi nozzle and an ejector nozzle were used to inject sodium hypochlorite. It was found that the ejector nozzle had higher processing performance than the Venturi nozzle, and was effective for high flow rates of ballast water. It was clarified that high plankton extinction ratios could be obtained using mechanochemical cavitation provided by ejector nozzles.http://deepblue.lib.umich.edu/bitstream/2027.42/84238/1/CAV2009-final37.pd
User-Adaptive A Posteriori Restoration for Incorrectly Segmented Utterances in Spoken Dialogue Systems
Ideally, the users of spoken dialogue systems should be able to speak at their own tempo. Thus, the systems needs to interpret utterances from various users correctly, even when the utterances contain pauses. In response to this issue, we propose an approach based on a posteriori restoration for incorrectly segmented utterances. A crucial part of this approach is to determine whether restoration is required. We use a classification-based approach, adapted to each user. We focus on each user’s dialogue tempo, which can be obtained during the dialogue, and determine the correlation between each user’s tempo and the appropriate thresholds for classification. A linear regression function used to convert the tempos into thresholds is also derived. Experimental results show that the proposed user adaptation approach applied to two restoration classification methods, thresholding and decision trees, improves classification accuracies by 3.0% and 7.4%, respectively, in cross validation
Stau relic density at the Big-Bang nucleosynthesis era consistent with the abundance of the light element nuclei in the coannihilation scenario
We calculate the relic density of stau at the beginning of the Big-Bang
Nucleosynthesis (BBN) era in the coannihilation scenario of minimal
supersymmetric standard model (MSSM). In this scenario, stau can be long-lived
and form bound states with nuclei. We put constraints on the parameter space of
MSSM by connecting the calculation of the relic density of stau to the
observation of the light elements abundance, which strongly depends on the
relic density of stau. Consistency between the theoretical prediction and the
observational result, both of the dark matter abundance and the light elements
abundance, requires the mass difference between the lighter stau and the
lightest neutralino to be around 100MeV, the stau mass to be 300 -- 400 GeV,
and the mixing angle of the left and right-handed staus to be
.Comment: 9 pages, 5 figures, figure 5 correcte
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