1,079 research outputs found
Gluino-mediated electroweak penguin with flavor-violating trilinear couplings
In light of a discrepancy of the direct violation in
decays, , we investigate gluino contributions to
the electroweak penguin, where flavor violations are induced by squark
trilinear couplings. Top-Yukawa contributions to observables are
taken into account, and vacuum stability conditions are evaluated in detail. It
is found that this scenario can explain the discrepancy of
for the squark mass smaller than 5.6 TeV. We also
show that the gluino contributions can amplify , and . Such large effects could be measured in future
experiments.Comment: 30 pages, 8 figures; references added, version published in JHE
Numerical study of the hadron-quark mixed phase
The Coulomb screening effect and the finite-size effect such as surface
tension are figured out in the hadron-quark deconfinement phase transition. We
study the mixed phase of the quark droplets immersed in hadron matter. We see
that the droplet phase is mechanically unstable if the surface tension is
strong enough. Once the Coulomb potential is properly taken into account, we
could effectively satisfy the condition for charge chemical equilibrium in the
Maxwell construction. As a result, we suggest the Maxwell construction revives
the physical meaning effectively.Comment: 4 pages, 4figures, proceeding of Phase Transitions in Strongly
Interacting Matter 18th International Nuclear Physics Divisional Conference
of the EPS (NPDC18)Europhysics Conferenc
Split Generation in the SUSY Mass Spectrum and B_s-{\bar B}_s Mixing
We show that the like-sign di-muon anomaly reported recently by the D0
Collaboration can be explained in the supersymmetric standard model (SM) if the
squarks and the sleptons in the first two generations have relatively small,
but degenerate mass spectrum, and those in the third generation are larger as
O(1-10)TeV. This split generation model provides large contributions to the
B_s-{\bar B}_s mixing, although most of the FCNC's are suppressed due to the
large masses of the third generation squarks or the GIM mechanism partially
acting on the first and second generations.Comment: 15 pages, 1 figur
A Novel Pollen-Pistil Interaction Conferring High-Temperature Tolerance during Reproduction via CLE45 Signaling
SummaryFlowering plants in the reproductive stage are particularly vulnerable to ambient temperature fluctuations [1–6]. Nevertheless, they maintain seed production under certain levels of exposure to temperature change. The mechanisms underlying this temperature tolerance are largely unknown. Using an in vitro Arabidopsis pollen tube culture, we found that a synthetic CLV3/ESR-related peptide, CLE45, prolonged pollen tube growth. A subsequent screen of Arabidopsis mutants of leucine-rich repeat receptor-like kinase genes identified two candidate receptors for CLE45 peptide, STERILITY-REGULATING KINASE MEMBER1 (SKM1) and SKM2. The double loss-of-function mutant was insensitive to CLE45 peptide in terms of pollen tube growth in vitro. The SKM1 protein actually interacted with CLE45 peptide. CLE45 was preferentially expressed in the stigma in the pistil at 22°C, but upon temperature shift to 30°C, its expression expanded to the transmitting tract, along which pollen tubes elongated. In contrast, both SKM1 and SKM2 were expressed in pollen. Disturbance of CLE45-SKM1/SKM2 signaling transduction by either RNAi suppression of CLE45 expression or introduction of a kinase-dead version of SKM1 into skm1 plants reduced seed production at 30°C, but not at 22°C. Taken together with the finding that CLE45 peptide application alleviated mitochondrial decay during the in vitro pollen tube culture, these results strongly suggest that the pollen-pistil interaction via the CLE45-SKM1/SKM2 signaling pathway sustains pollen performance under higher temperatures, leading to successful seed production
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