746 research outputs found
LHC phenomenology of natural MSSM with non-universal gaugino masses at the unification scale
In this letter, we study collider phenomenology in the supersymmetric
Standard Model with a certain type of non-universal gaugino masses at the gauge
coupling unification scale, motivated by the little hierarchy problem. In this
scenario, especially the wino mass is relatively large compared to the gluino
mass at the unification scale, and the heavy wino can relax the fine-tuning of
the higgsino mass parameter, so-called -parameter. Besides, it will
enhance the lightest Higgs boson mass due to the relatively large left-right
mixing of top squarks through the renormalization group (RG) effect. Then
GeV Higgs boson could be accomplished, even if the top squarks are lighter than
TeV and the parameter is within a few hundreds GeV. The right-handed
top squark tends to be lighter than the other sfermions due to the RG runnings,
then we focus on the top squark search at the LHC. Since the top squark is
almost right-handed and the higgsinos are nearly degenerate, channel is the most sensitive to this scenario. We figure out current
and expected experimental bounds on the lightest top squark mass and model
parameters at the gauge coupling unification scale.Comment: 15 pages, 5 figures, 1 table; added references and clarification
Duality cascade of softly broken supersymmetric theories
We study the duality cascade of softly broken supersymmetric theories. We
investigate the renormalization group (RG) flow of SUSY breaking terms as well
as supersymmetric couplings. It is found that the magnitudes of SUSY breaking
terms are suppressed in most regimes of the RG flow through the duality
cascade. At one stage of cascading, the gaugino mass of the strongly coupled
sector and scalar masses converge to certain values, which are determined by
the gauge coupling and the gaugino mass of the weakly coupled sector. At the
next stage, the strongly and weakly coupled sectors are interchanged with each
other. We also show the possibility that cascading would be terminated by the
gauge symmetry breaking, which is induced by the so-called B-term.Comment: 25 pages, 5 figure
Addition of Some Transition Elements and their Effects on the Electrochemical Properties of MgNi
In this study, some transition elements, Ag, Co, Pd, Re, Ru and Ti, at 6 and 10mol% compositions, were selected to ball mill with Mg2Ni and Ni, and the effects of transition elements on the electrochemical properties of amorphous MgNi were investigated. Three distinct effects on the electrochemical properties of MgNi were found: Ti and Pd dissolved into the bulk of MgNi during ball milling and the degradation of discharge capacity was decreased by addition of Ti and Pd. Ag and Co also dissolved in the MgNi powder, but there was no appreciable influence on the electrochemical behavior of MgNi. Re and Ru neither dissolved into MgNi nor improved the properties of MgNi
Effects of Pd Addition on the Electrochemical Properties of MgNi
Two groups of Pd-modified MgNi samples were prepared: sample Ⅰ, ball-milling Pd (1, 6 and 10 mol%) with amorphous MgNi for 10 min, 2hr or 10 hr, sample Ⅱ, ball-milling 10 mol% Pd with Mg2Ni and Ni for 80 hr. Effects of the addition of Pd on the electrochemical properties of MgNi were investigated. For sample Ⅰ, the effects of Pd depended on both the Pd ratio and the time of ball-milling. During ball-milling, Pd bebame amorphous and was distributed uniformly on the surface of MgNi particle. At 6 mol% and 10 mol% Pd, degradation of the discharge capacity of MgNi was significantly decreased. As for sample Ⅱ, the cycle life of MgNi was remarkably improved by Pd modification. The roles of Pd in the behavior of MgNi were analyzed, and the improvements in MgNi properties arising from both modifications by Pd were thought to be due to the prevention of the formation of Mg(OH)2
Dark matter physics, flavor physics and LHC constraints in the dark matter model with a bottom partner
In the scenario that a dark matter (DM) is a weakly interacting massive
particle, there are many possibilities of the interactions with the Standard
Model (SM) particles to achieve the relic density of DM. In this paper, we
consider one simple DM model where the DM candidate is a complex scalar and
interacts with the SM particles via exchange of the Higgs particle and an extra
quark, named bottom partner. The extra quark carries the same quantum number as
the right-handed down-type quarks and has Yukawa couplings with the DM
candidate and the right-handed down-type quarks. The Yukawa interactions are
not only relevant to the thermal relic density of the DM, but also contribute
to the flavor physics, such as the processes. In addition, the
flavor alignment of the Yukawa couplings is related to the decay modes of the
extra quark. Then, we can find the explicit correlations among the physical
observables in DM physics, flavor physics and the signals at the LHC. Based on
the numerical analyses of the thermal relic density, the direct detection of
the DM and the current LHC bounds using the latest results, we survey our
predictions for the processes. We investigate the perturbative
bound on the Yukawa coupling, as well. Study of a fermionic DM model with extra
scalar quarks is also given for comparison.Comment: 18 pages, 8 figures, 2 tables; some typos corrected, version
published in JHE
GOGOT: a method for the identification of differentially expressed fragments from cDNA-AFLP data
<p>Abstract</p> <p>Background</p> <p>One-dimensional (1-D) electrophoretic data obtained using the cDNA-AFLP method have attracted great interest for the identification of differentially expressed transcript-derived fragments (TDFs). However, high-throughput analysis of the cDNA-AFLP data is currently limited by the need for labor-intensive visual evaluation of multiple electropherograms. We would like to have high-throughput ways of identifying such TDFs.</p> <p>Results</p> <p>We describe a method, GOGOT, which automatically detects the differentially expressed TDFs in a set of time-course electropherograms. Analysis by GOGOT is conducted as follows: correction of fragment lengths of TDFs, alignment of identical TDFs across different electropherograms, normalization of peak heights, and identification of differentially expressed TDFs using a special statistic. The output of the analysis is a highly reduced list of differentially expressed TDFs. Visual evaluation confirmed that the peak alignment was performed perfectly for the TDFs by virtue of the correction of peak fragment lengths before alignment in step 1. The validity of the automated ranking of TDFs by the special statistic was confirmed by the visual evaluation of a third party.</p> <p>Conclusion</p> <p>GOGOT is useful for the automated detection of differentially expressed TDFs from cDNA-AFLP temporal electrophoretic data. The current algorithm may be applied to other electrophoretic data and temporal microarray data.</p
- …